pubchem-mcp-server

Previous value: -"Filter to assays against this target protein accession (UniProt/RefSeq/GenBank/PDB chain), e.g. \"P35354\", including assays recorded only under a Gene ID or another accession this compound's assay table pairs with it. Uppercased before matching; a PDB chain ID (the \"A\" in \"1ZHH_A\") is kept as given. With targetGeneId, both must name the same target — when the table ties them to different targets, nothing matches. Obtain accessions from pubchem_search_assays or the targetAccession field of an unfiltered result here."New value: +"Filter to assays against this target protein accession (UniProt/RefSeq/GenBank/PDB chain), e.g. \"P35354\", including assays recorded only under a Gene ID or another accession this compound's assay table pairs with it. Uppercased before matching; a PDB chain ID (the \"A\" in \"1ZHH_A\") is kept as given. With targetGeneId, both must name the same target — when the table ties them to different targets, nothing matches. Obtain accessions from an assay's targets in pubchem_get_summary (entityType \"assay\"), the accession:X in a pubchem_get_compound_interactions target entry's partner, or the targetAccession field of a result here without a target filter."

Previous value: -"Filter to assays against this NCBI Gene ID (1 to 2147483647), including assays recorded only under a protein accession this compound's assay table pairs with the Gene ID (e.g. 5742 also reaches rows carrying only P23219 when another row pairs the two). Obtain Gene IDs from pubchem_search_assays or the targetGeneId field of an unfiltered result here. Combine with outcomeFilter=\"active\" to answer \"is this compound active against target T?\"."New value: +"Filter to assays against this NCBI Gene ID (1 to 2147483647), including assays recorded only under a protein accession this compound's assay table pairs with the Gene ID (e.g. 5742 also reaches rows carrying only P23219 when another row pairs the two). Obtain Gene IDs from the GeneID:N in a pubchem_get_compound_interactions target entry's partner (kinds: [\"target\"]) or the targetGeneId field of a result here without a target filter (rows from untargeted screens carry none). Combine with outcomeFilter=\"active\" to answer \"is this compound active against target T?\"."

Previous value: -"Interaction kinds that could not be retrieved (comma-separated). The returned entries cover the kinds that succeeded. The notice says, per failed kind, whether a retry can help: a timeout or upstream error can clear, while a refusal from PubChem's SDQ service (drug-drug) does not."New value: +"Interaction kinds that could not be retrieved (comma-separated). The returned entries cover the kinds that succeeded. The notice says, per failed kind, whether a retry can help: a timeout, rate limit, network error, unreadable response, or upstream 5xx other than 501 can clear, while an HTTP 400, 403, or 501, a response in a shape the server does not expect, or a refusal from PubChem's SDQ service (drug-drug) does not."

Previous value: -"Target identifier type. \"genesymbol\" and \"proteinname\" accept text names. \"geneid\" accepts NCBI Gene IDs. \"proteinaccession\" accepts UniProt accessions."New value: +"Target identifier type. \"genesymbol\" and \"proteinname\" accept text names; a genesymbol matches the symbol case-insensitively across species, so a human symbol also returns assays on other species' orthologs. \"geneid\" accepts NCBI Gene IDs. \"proteinaccession\" accepts UniProt accessions. \"geneid\" and \"proteinaccession\" each pin one protein, but return overlapping, different assay sets for it, since PubChem records some assays under only one of the two identifiers; for a complete list for one protein, union both."

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_target_query`: targetQuery is empty or whitespace-only. `invalid_geneid_query`: targetType is \"geneid\" but targetQuery contains characters other than digits. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_target_query`: targetQuery is empty or whitespace-only. `invalid_geneid_query`: targetType is \"geneid\" but targetQuery contains characters other than digits. `target_query_rejected`: PubChem refused the target lookup with HTTP 400 — its answer for a targetQuery carrying a line break, another C0 control character other than tab and NUL, or DEL. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "blank_target_query",
-  "invalid_geneid_query"
-]New value: +[
+  "blank_target_query",
+  "invalid_geneid_query",
+  "target_query_rejected"
+]

Previous value: -"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted or blank. `missing_structure_args`: substructure/superstructure/similarity search with query or queryType omitted, or a blank query. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not an integer CID from 1 to 2147483647. `offset_ceiling_exceeded`: formula, substructure, superstructure, or similarity search with offset above 10000. `missing_aid`: searchType is \"assay\" but aid was omitted. `aid_not_found`: assay search where PubChem has no live assay with the given AID. `identifier_rejected`: identifier search where PubChem rejected every identifier in the batch as unreadable (HTTP 400) — for SMILES or InChI, a string it could not standardize into a structure. A batch with any other outcome lists rejected inputs in unresolvedIdentifiers instead. `search_query_rejected`: PubChem failed a formula, substructure, superstructure, or similarity search with HTTP 500 \"Search status indicates failure\" — its answer for a malformed SMILES or formula, a SMILES with a \"*\" wildcard atom, or a CID with no record. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted or blank. `missing_structure_args`: substructure/superstructure/similarity search with query or queryType omitted, or a blank query. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not an integer CID from 1 to 2147483647. `offset_ceiling_exceeded`: formula, substructure, superstructure, or similarity search with offset above 10000. `missing_aid`: searchType is \"assay\" but aid was omitted. `aid_not_found`: assay search where PubChem has no live assay with the given AID. `identifier_rejected`: identifier search where PubChem rejected every identifier in the batch as unreadable (HTTP 400) — for SMILES or InChI, a string it could not standardize into a structure. A batch with any other outcome lists rejected inputs in unresolvedIdentifiers instead. `search_query_rejected`: PubChem failed a formula, substructure, superstructure, or similarity search with HTTP 500 \"Search status indicates failure\" — its answer for a malformed SMILES or formula, a SMILES with a \"*\" wildcard atom, or a CID with no record — or refused any of these searches with HTTP 400, as it does a formula carrying a line break, another C0 control character other than tab and NUL, or DEL. Other values are possible when a failure originates below the handler."

Added value: +{
+  "description": "Keep only assays of these types: \"confirmatory\" (dose-response and other follow-up assays), \"screening\" (primary high-throughput screens), \"summary\" (records summarizing a project's assays), \"other\". Matched against PubChem's Assay Type regardless of case; an assay with no recorded type matches none. Combines with outcomeFilter and the target filters — an assay must pass all of them. Omit to keep every type.",
+  "items": {
+    "enum": [
+      "confirmatory",
+      "screening",
+      "summary",
+      "other"
+    ],
+    "type": "string"
+  },
+  "minItems": 1,
+  "type": "array"
+}

Added value: +{
+  "description": "Assay types kept, comma-separated (e.g. \"confirmatory, summary\"), when assayType is set.",
+  "type": "string"
+}

Previous value: -"Exact number of assays matching the outcome and target filters, across all pages."New value: +"Exact number of assays matching the outcome, target, and assay-type filters, across all pages."

Added value: +{
+  "description": "PubChem's assay type as written: Confirmatory, Screening, Summary, or Other. Omitted when PubChem records none.",
+  "type": "string"
+}

Added value: +{
+  "description": "PubMed IDs of the publications the assay cites, highest (most recently assigned) first. Omitted when it cites none.",
+  "items": {
+    "type": "number"
+  },
+  "type": "array"
+}

Previous value: -[
-  "drug-drug"
-]New value: +[
+  "drug-food"
+]

Previous value: -"Interaction kinds to fetch. \"drug-drug\" (interactions with other drugs), \"drug-food\" (dietary interactions), \"target\" (binding/activity against molecular targets). \"drug-drug\" and \"target\" come from PubChem's SDQ service, which can refuse automated requests; \"drug-food\" comes from PUG View. Per-target activity is also available from pubchem_get_bioactivity. Default: [\"drug-drug\"]."New value: +"Interaction kinds to fetch. \"drug-food\" (dietary interactions, from PUG View), \"target\" (molecular targets from the compound's assay summary: one entry per Gene ID with the accessions the table pairs with it, and one per identifier it never pairs, so a Gene ID and an accession that no row pairs are separate entries even when they name the same protein), \"drug-drug\" (interactions with other drugs, from PubChem's SDQ service, which refuses automated requests, so it is reported in failedKinds). Default: [\"drug-food\"]."

Previous value: -"Zero-based start position within each requested kind, counted in source records rather than returned entries. The same offset applies to every kind in the call, and the kinds advance at different rates — when paging past the first page, request one kind per call and pass that kind's nextOffset. Default: 0."New value: +"Zero-based start position within each requested kind, counted in records (molecular targets, for target) rather than returned entries. The same offset applies to every kind in the call, and the kinds advance at different rates — when paging past the first page, request one kind per call and pass that kind's nextOffset. Default: 0."

Previous value: -"Interacting compound, food, or target name as the source reports it."New value: +"Interacting compound as the source reports it. For a target: its gene or protein name and organism, then the identifier pubchem_get_bioactivity filters on (GeneID:N → targetGeneId, accession:X → targetAccession); the identifier alone when no name resolves. A target whose identifiers join several Gene IDs is named by the accession they share and says \"group of N Gene IDs\"."

Previous value: -"Originating source (e.g. \"DrugBank\", \"BindingDB\")."New value: +"Originating source (e.g. \"DrugBank\", \"PubChem BioAssay\")."

Previous value: -"The interaction statement."New value: +"The interaction statement. For a target: the assays naming it by outcome and its most potent Active value with that AID, in µM."

Previous value: -"Interaction kinds that could not be retrieved (comma-separated). The returned entries cover the kinds that succeeded. The notice says, per failed kind, whether a retry can help: a timeout or upstream error can clear, while a refusal from PubChem's SDQ service (drug-drug, target) does not."New value: +"Interaction kinds that could not be retrieved (comma-separated). The returned entries cover the kinds that succeeded. The notice says, per failed kind, whether a retry can help: a timeout or upstream error can clear, while a refusal from PubChem's SDQ service (drug-drug) does not."

Previous value: -"Guidance when a kind failed, when no interaction data was found, when the offset runs past every requested kind, or when further pages remain. Absent when this page is complete and every kind resolved."New value: +"Guidance when a kind failed, when no interaction data was found, when the offset runs past every requested kind, when target names could not be retrieved, or when further pages remain. Absent when this page is complete and every kind resolved."

Previous value: -"Source records available for this kind, across all pages. Entries are derived from these records and can be fewer: a \"target\" record naming no molecular target and a \"drug-drug\" record carrying no statement both yield nothing, and duplicate measurements collapse within a page. Pages divide the records, not the entries, so a duplicate split across two pages is reported on both."New value: +"Records available for this kind, across all pages: interaction records for drug-drug and drug-food, molecular targets for target. Entries are derived from these records and can be fewer: a drug-drug record carrying no statement yields nothing. Pages divide the records, not the entries."

Previous value: -"Cross-reference types to retrieve. String IDs: RegistryID (DSSTox/EPA registry numbers), RN (CAS numbers), PatentID. Numeric IDs: PubMedID, GeneID (NCBI Gene), ProteinGI (legacy NCBI Protein GI), TaxonomyID."New value: +"Cross-reference types to retrieve. String IDs: CAS (the CAS Registry Numbers deposited for this compound, most-attested first, each with the number of source records that deposited it — the first is the value most source records agree on), EC (European Community numbers, ordered and counted the same way), RN (every registry number PubChem associates with the record, unranked: the CAS number alongside deprecated and related CAS RNs, CAS RNs of other substances mapped to the structure, and EC numbers), RegistryID (DSSTox/EPA registry numbers), PatentID. Numeric IDs: PubMedID, GeneID (NCBI Gene — use it for gene/protein associations), ProteinGI (legacy NCBI Protein GI; PubChem currently returns no data for it, so use GeneID instead), TaxonomyID."

Previous value: -[
-  "RegistryID",
-  "RN",
-  "PubMedID",
-  "PatentID",
-  "GeneID",
-  "ProteinGI",
-  "TaxonomyID"
-]New value: +[
+  "RegistryID",
+  "RN",
+  "PubMedID",
+  "PatentID",
+  "GeneID",
+  "ProteinGI",
+  "TaxonomyID",
+  "CAS",
+  "EC"
+]

Added value: +{
+  "description": "Requested xref types that could not be retrieved (comma-separated). The returned groups cover the types that loaded. A retry can recover a type that failed transiently (a timeout, network error, rate limit, or 5xx), and the notice names those; a type PubChem rejected fails the same way again.",
+  "type": "string"
+}

Previous value: -"Recovery guidance when every requested xref type returned zero IDs, when the offset runs past every type, or when further pages remain. Absent when this page is complete and non-empty."New value: +"Guidance when a type failed to load, when every requested xref type returned zero IDs, when the offset runs past every type, when further pages remain, or when ProteinGI came back empty (PubChem serves no ProteinGI data). Absent when this page is complete and non-empty."

Previous value: -"Cross-references grouped by type."New value: +"Cross-references grouped by type, one group per requested type that loaded. A type listed in failedTypes is absent — its IDs are unknown, not empty."

Previous value: -"Cross-reference IDs on this page (window of offset + maxPerType). PubMedID is sorted numerically descending, so page one holds the highest, most recently assigned PMIDs; GeneID, ProteinGI and TaxonomyID numerically ascending; RegistryID, RN and PatentID keep PubChem's order."New value: +"Cross-reference IDs on this page (window of offset + maxPerType). PubMedID is sorted numerically descending, so page one holds the highest, most recently assigned PMIDs; GeneID, ProteinGI and TaxonomyID numerically ascending; CAS and EC by the number of source records that deposited each, most first (ties in PubChem's order), so ids[0] is the value most source records agree on; RegistryID, RN and PatentID keep PubChem's order."

Added value: +{
+  "description": "CAS and EC only: how many source records deposited each ID on this page, aligned with ids — sourceCounts[i] is the count for ids[i]. One source can deposit several records, so this counts records, not distinct source names. More than one ID means the source records disagree; the counts show by how much.",
+  "items": {
+    "description": "Number of source records that deposited the ID at this index.",
+    "type": "number"
+  },
+  "type": "array"
+}

Previous value: -"Cross-reference type: RegistryID, RN, PubMedID, PatentID, GeneID, ProteinGI, or TaxonomyID."New value: +"Cross-reference type: CAS, EC, RN, RegistryID, PubMedID, PatentID, GeneID, ProteinGI, or TaxonomyID. PubChem currently returns no data for ProteinGI; GeneID carries gene/protein associations."

Previous value: -"Entity identifiers. A comma-joined string is split into one identifier per piece, with whitespace trimmed. The per-call cap is 10 pieces: the first 10 are looked up, and any past that are returned in unprocessed, in input order, and reported in cappedInputs. More than 1000 pieces in all fails the call. ID form depends on entityType:\n- assay: AID, a positive integer, e.g. [\"1000\"]\n- gene: NCBI Gene ID, a positive integer, e.g. [\"1956\"]\n- protein: UniProt accession, e.g. [\"P00533\"]\n- taxonomy: NCBI Taxonomy ID, a positive integer, e.g. [\"9606\"]\nFor assay, gene, and taxonomy, a piece that is not a positive integer written in digits is marked invalid and not looked up."New value: +"Entity identifiers. A comma-joined string is split into one identifier per piece, with whitespace trimmed. The per-call cap is 10 pieces: the first 10 are looked up, and any past that are returned in unprocessed, in input order, and reported in cappedInputs. More than 1000 pieces in all fails the call. ID form depends on entityType:\n- assay: AID, a positive integer, e.g. [\"1000\"]\n- gene: NCBI Gene ID, a positive integer, e.g. [\"1956\"]\n- protein: UniProt accession, e.g. [\"P00533\"]\n- taxonomy: NCBI Taxonomy ID, a positive integer, e.g. [\"9606\"]\nFor assay, gene, and taxonomy, a piece that is not a positive integer up to 2147483647 written in digits is marked invalid and not looked up."

Previous value: -"Machine-readable failure mode. Declared by this tool: `too_many_identifiers`: Comma splitting yields more than 1000 identifier pieces. `invalid_identifier`: No identifier piece is usable: every piece is blank, or, for assay, gene, or taxonomy, not a positive integer. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `too_many_identifiers`: Comma splitting yields more than 1000 identifier pieces. `invalid_identifier`: No identifier piece is usable: every piece is blank, or, for assay, gene, or taxonomy, not a positive integer up to 2147483647. Other values are possible when a failure originates below the handler."

Previous value: -"Assay method as PubChem labels it, e.g. \"confirmatory\" (dose-response) or \"screening\" (assay summaries). Omitted when PubChem records none."New value: +"Assay method as PubChem labels it (assay summaries): \"confirmatory\" (dose-response), \"screening\" (primary screen), \"summary\", or \"other\". Omitted when PubChem records none."

Previous value: -"Required for identifier search. Type of chemical identifier: \"name\", \"smiles\", or \"inchikey\"."New value: +"Required for identifier search. Type of chemical identifier: \"name\", \"smiles\", \"inchi\" (a full InChI string, case-sensitive), or \"inchikey\"."

Previous value: -[
-  "name",
-  "smiles",
-  "inchikey"
-]New value: +[
+  "name",
+  "smiles",
+  "inchi",
+  "inchikey"
+]

Previous value: -"Required for identifier search. Array of identifiers to resolve. The per-call cap is 25: the first 25 are looked up, and any past that (up to 1000 in all) are returned in unprocessed, in input order, and reported in cappedInputs. Examples: [\"aspirin\", \"ibuprofen\"] for name, [\"CC(=O)OC1=CC=CC=C1C(=O)O\"] for SMILES, [\"BSYNRYMUTXBXSQ-UHFFFAOYSA-N\"] for inchikey (27-char block format; uppercased before lookup, any case accepted)."New value: +"Required for identifier search. Array of identifiers to resolve. The per-call cap is 25: the first 25 are looked up, and any past that (up to 1000 in all) are returned in unprocessed, in input order, and reported in cappedInputs. Examples: [\"aspirin\", \"ibuprofen\"] for name, [\"CC(=O)OC1=CC=CC=C1C(=O)O\"] for SMILES, [\"InChI=1S/C9H8O4/c1-6(10)13-8-5-3-2-4-7(8)9(11)12/h2-5H,1H3,(H,11,12)\"] for inchi (sent exactly as written, case kept), [\"BSYNRYMUTXBXSQ-UHFFFAOYSA-N\"] for inchikey (27-char block format; uppercased before lookup, any case accepted)."

Previous value: -"Zero-based index of the first CID to return. Pass the nextOffset from a previous call to read the following page. Identifier lookups resolve every match up front, so paging them is free, and assay searches fetch only the requested page; formula, substructure, superstructure, and similarity searches have to ask PubChem for offset + maxResults records to reach a page, so deep pages cost progressively more upstream — hence the 10000 ceiling. Default: 0."New value: +"Zero-based index of the first CID to return. Pass the nextOffset from a previous call to read the following page. Identifier lookups resolve every match up front, so paging them is free, and assay searches fetch only the requested page, so both page to the end of their matches. Formula, substructure, superstructure, and similarity searches have to ask PubChem for offset + maxResults records to reach a page, so deep pages cost progressively more upstream: those four accept an offset up to 10000. Default: 0."

Previous value: -10000New value: +9007199254740991

Previous value: -"Search strategy; each mode needs its own fields. \"identifier\": name/SMILES/InChIKey lookup — requires identifierType and identifiers. \"formula\": molecular formula — requires formula. \"substructure\": find compounds containing the query as a substructure. \"superstructure\": find compounds that are themselves substructures of the query. \"similarity\": 2D Tanimoto similarity to the query. substructure, superstructure, and similarity require query and queryType. \"assay\": compounds tested in a PubChem bioassay — requires aid; activeOnly (default true) keeps only the compounds the assay marked active."New value: +"Search strategy; each mode needs its own fields. \"identifier\": name/SMILES/InChI/InChIKey lookup — requires identifierType and identifiers. \"formula\": molecular formula — requires formula. \"substructure\": find compounds containing the query as a substructure. \"superstructure\": find compounds that are themselves substructures of the query. \"similarity\": 2D Tanimoto similarity to the query. substructure, superstructure, and similarity require query and queryType. \"assay\": compounds tested in a PubChem bioassay — requires aid; activeOnly (default true) keeps only the compounds the assay marked active."

Previous value: -"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted or blank. `missing_structure_args`: substructure/superstructure/similarity search with query or queryType omitted, or a blank query. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not an integer CID from 1 to 2147483647. `missing_aid`: searchType is \"assay\" but aid was omitted. `aid_not_found`: assay search where PubChem has no live assay with the given AID. `identifier_rejected`: identifier search where PubChem rejected every identifier in the batch as unreadable (HTTP 400) — for SMILES, a string it could not standardize into a structure. A batch with any other outcome lists rejected inputs in unresolvedIdentifiers instead. `search_query_rejected`: PubChem failed a formula, substructure, superstructure, or similarity search with HTTP 500 \"Search status indicates failure\" — its answer for a malformed SMILES or formula, a SMILES with a \"*\" wildcard atom, or a CID with no record. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted or blank. `missing_structure_args`: substructure/superstructure/similarity search with query or queryType omitted, or a blank query. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not an integer CID from 1 to 2147483647. `offset_ceiling_exceeded`: formula, substructure, superstructure, or similarity search with offset above 10000. `missing_aid`: searchType is \"assay\" but aid was omitted. `aid_not_found`: assay search where PubChem has no live assay with the given AID. `identifier_rejected`: identifier search where PubChem rejected every identifier in the batch as unreadable (HTTP 400) — for SMILES or InChI, a string it could not standardize into a structure. A batch with any other outcome lists rejected inputs in unresolvedIdentifiers instead. `search_query_rejected`: PubChem failed a formula, substructure, superstructure, or similarity search with HTTP 500 \"Search status indicates failure\" — its answer for a malformed SMILES or formula, a SMILES with a \"*\" wildcard atom, or a CID with no record. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "missing_identifier_args",
-  "missing_formula",
-  "missing_structure_args",
-  "invalid_cid_query",
-  "missing_aid",
-  "aid_not_found",
-  "identifier_rejected",
-  "search_query_rejected"
-]New value: +[
+  "missing_identifier_args",
+  "missing_formula",
+  "missing_structure_args",
+  "invalid_cid_query",
+  "offset_ceiling_exceeded",
+  "missing_aid",
+  "aid_not_found",
+  "identifier_rejected",
+  "search_query_rejected"
+]

Previous value: -"Offset to pass on the next call to continue past this page. Omitted when no further matches remain."New value: +"Offset to pass on the next call to continue past this page. Omitted when no further matches remain, and when a formula, substructure, superstructure, or similarity page would continue past the 10000 offset ceiling (truncated stays true, and the notice says how to narrow the search and names the page at offset 10000 when it still reaches further matches)."

Previous value: -"Recovery guidance when no compounds matched (for an assay search, when the assay recorded none of the requested kind), when the offset runs past the matches observed, when identifiers had no match or could not be interpreted, when identifiers collided on one CID, or when further pages remain. Absent when this page is complete and every identifier resolved to its own CID."New value: +"Recovery guidance when no compounds matched (for an assay search, when the assay recorded none of the requested kind), when the offset runs past the matches observed, when identifiers had no match or could not be interpreted, when identifiers collided on one CID, when further pages remain, or when a bounded search reached the offset ceiling. Absent when this page is complete and every identifier resolved to its own CID."

Previous value: -9007199254740991New value: +2147483647

Previous value: -"Max assay results to return per page (1-100). Well-studied compounds have thousands of records; use offset to reach the ones past this page. Default: 20."New value: +"Max assay results to return per page. The per-call cap is 100: a larger value (up to 1000) returns a page of 100 and is reported in cappedInputs. Well-studied compounds have thousands of records; use offset to reach the ones past this page. Default: 20."

Previous value: -100New value: +1000

Previous value: -"Filter by activity outcome. \"active\" shows only assays where the compound showed activity — most useful for understanding biological profile. Default: \"all\"."New value: +"Filter by activity outcome against each assay's reported target: the target a target filter matched, else the first target the assay lists. For a multi-target assay, outcomes against its other targets (in otherTargets) do not count. \"active\" keeps assays where that outcome is Active — most useful for understanding biological profile. Default: \"all\"."

Previous value: -"Filter to assays against this target protein accession (UniProt/GenBank), e.g. \"P35354\". Obtain accessions from pubchem_search_assays or the targetAccession field of an unfiltered result here."New value: +"Filter to assays against this target protein accession (UniProt/RefSeq/GenBank/PDB chain), e.g. \"P35354\", including assays recorded only under a Gene ID or another accession this compound's assay table pairs with it. Uppercased before matching; a PDB chain ID (the \"A\" in \"1ZHH_A\") is kept as given. With targetGeneId, both must name the same target — when the table ties them to different targets, nothing matches. Obtain accessions from pubchem_search_assays or the targetAccession field of an unfiltered result here."

Previous value: -"Filter to assays against this NCBI Gene ID. Obtain Gene IDs from pubchem_search_assays or the targetGeneId field of an unfiltered result here. Combine with outcomeFilter=\"active\" to answer \"is this compound active against target T?\"."New value: +"Filter to assays against this NCBI Gene ID (1 to 2147483647), including assays recorded only under a protein accession this compound's assay table pairs with the Gene ID (e.g. 5742 also reaches rows carrying only P23219 when another row pairs the two). Obtain Gene IDs from pubchem_search_assays or the targetGeneId field of an unfiltered result here. Combine with outcomeFilter=\"active\" to answer \"is this compound active against target T?\"."

Previous value: -9007199254740991New value: +2147483647

Previous value: -"Assays with \"Active\" outcome."New value: +"Assays whose outcome against their first listed target is \"Active\", across all assays and before any filter. A multi-target assay counts by its first target only."

Previous value: -"The maxResults cap that was applied."New value: +"The page size applied: maxResults, or the per-call cap when maxResults exceeds it."

Added value: +{
+  "description": "Inputs that asked for more than their per-call cap, with the value requested and the value served. An ID batch lists the IDs past the cap in unprocessed. Omitted when every input was within its cap.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One input served at its per-call cap.",
+    "properties": {
+      "input": {
+        "description": "Input name, e.g. \"maxResults\" or \"cids\".",
+        "type": "string"
+      },
+      "requested": {
+        "description": "Value requested: the page size, or the number of IDs in the batch.",
+        "type": "number"
+      },
+      "served": {
+        "description": "Value served: the per-call cap.",
+        "type": "number"
+      },
+      "unprocessed": {
+        "description": "ID batches only: IDs past the cap, listed in unprocessed in input order.",
+        "type": "number"
+      }
+    },
+    "required": [
+      "input",
+      "requested",
+      "served"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Assays with \"Inactive\" outcome."New value: +"Assays whose outcome against their first listed target is \"Inactive\", across all assays and before any filter. A multi-target assay counts by its first target only."

Previous value: -"Quantitative activity measurements."New value: +"Quantitative activity measurements against the reported target."

Added value: +{
+  "description": "The assay's other targets, each with its own outcome and measurements. Present only for an assay whose rows name more than one target.",
+  "items": {
+    "additionalProperties": false,
+    "description": "Another target of the assay, with its own outcome and values.",
+    "properties": {
+      "accession": {
+        "description": "Protein accession. Omitted when the row names none.",
+        "type": "string"
+      },
+      "activityValues": {
+        "description": "Quantitative activity measurements against this target.",
+        "items": {
+          "additionalProperties": false,
+          "description": "Quantitative activity measurement entry.",
+          "properties": {
+            "name": {
+              "description": "Measurement name (e.g. IC50, EC50, Ki). Omitted when not reported.",
+              "type": "string"
+            },
+            "unit": {
+              "description": "Unit of measurement (e.g. uM, nM). Omitted when not reported.",
+              "type": "string"
+            },
+            "value": {
+              "description": "Measured value.",
+              "type": "number"
+            }
+          },
+          "required": [
+            "value"
+          ],
+          "type": "object"
+        },
+        "type": "array"
+      },
+      "geneId": {
+        "description": "NCBI Gene ID. Omitted when the row names none.",
+        "type": "number"
+      },
+      "outcome": {
+        "description": "Activity outcome against this target.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "outcome",
+      "activityValues"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Activity outcome: Active, Inactive, Inconclusive, Unspecified."New value: +"Activity outcome against the reported target — the one a target filter matched, else the assay's first: Active, Inactive, Inconclusive, Unspecified."

Previous value: -"Target protein accession (UniProt/GenBank)."New value: +"Reported target's protein accession (UniProt/RefSeq/GenBank/PDB chain)."

Previous value: -"Target NCBI Gene ID."New value: +"Reported target's NCBI Gene ID."

Previous value: -"Target filter applied (gene ID and/or protein accession), when set."New value: +"Target identifiers matched, when a target filter is set: those passed plus every Gene ID and accession the compound's assay table pairs with them. When the two inputs name different targets, only the two inputs."

Previous value: -9007199254740991New value: +2147483647

Previous value: -"Machine-readable failure mode. Declared by this tool: `no_3d_structure`: PubChem has no computed 3D conformer for the requested CID. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `no_3d_structure`: PubChem returned 404 for the CID's 3D record, its answer both when the compound has no computed 3D conformer (common for very large molecules, mixtures, and undefined salts) and when no compound has the CID. Other values are possible when a failure originates below the handler."

Previous value: -"PubChem Compound IDs to fetch (1-100). Resolve from names/SMILES with pubchem_search_compounds."New value: +"PubChem Compound IDs to fetch. The per-call cap is 100: the first 100 are fetched, and any past that (up to 1000 in all) are returned in unprocessed, in input order, and reported in cappedInputs. Resolve from names/SMILES with pubchem_search_compounds."

Previous value: -9007199254740991New value: +2147483647

Previous value: -100New value: +1000

Previous value: -"Max number of distinct description entries per compound per page (1-20). PubChem returns near-duplicate summaries from many depositors; duplicates are collapsed before this cap applies. Default: 3."New value: +"Max number of distinct description entries per compound per page. The per-call cap is 20: a larger value (up to 1000) returns 20 per compound and is reported in cappedInputs. PubChem returns near-duplicate summaries from many depositors; duplicates are collapsed before this cap applies. Default: 3."

Previous value: -20New value: +1000

Previous value: -"Max synonyms returned per compound per page (1-100). PubChem lists hundreds for common drugs; use synonymOffset to reach the ones past this page. Default: 20."New value: +"Max synonyms returned per compound per page. The per-call cap is 100: a larger value (up to 1000) returns 100 per compound and is reported in cappedInputs. PubChem lists hundreds for common drugs; use synonymOffset to reach the ones past this page. Default: 20."

Previous value: -100New value: +1000

Added value: +{
+  "description": "Inputs that asked for more than their per-call cap, with the value requested and the value served. An ID batch lists the IDs past the cap in unprocessed. Omitted when every input was within its cap.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One input served at its per-call cap.",
+    "properties": {
+      "input": {
+        "description": "Input name, e.g. \"maxResults\" or \"cids\".",
+        "type": "string"
+      },
+      "requested": {
+        "description": "Value requested: the page size, or the number of IDs in the batch.",
+        "type": "number"
+      },
+      "served": {
+        "description": "Value served: the per-call cap.",
+        "type": "number"
+      },
+      "unprocessed": {
+        "description": "ID batches only: IDs past the cap, listed in unprocessed in input order.",
+        "type": "number"
+      }
+    },
+    "required": [
+      "input",
+      "requested",
+      "served"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Compound detail records."New value: +"Compound detail records, one per CID fetched, in input order. CIDs past the per-call cap are in unprocessed instead."

Previous value: -"ATC codes with hierarchical descriptions."New value: +"Human ATC codes in the order PubChem lists them. ATCvet codes and codes named only by a WHO Essential Medicines list are excluded."

Previous value: -"ATC code entry with hierarchical description."New value: +"One human ATC code with its WHO hierarchy."

Previous value: -"ATC code."New value: +"ATC level-5 (substance) code, e.g. \"N02BA01\"."

Previous value: -"ATC code description."New value: +"WHO ATC name for the code, e.g. \"Acetylsalicylic acid\". Empty when PubChem lists the code without a WHO ATC hierarchy entry."

Added value: +{
+  "description": "Levels 1-4 of the code, top-down: anatomical main group, therapeutic subgroup, pharmacological subgroup, chemical subgroup. Empty when PubChem lists the code without a WHO ATC hierarchy entry.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One ancestor level of the code.",
+    "properties": {
+      "code": {
+        "description": "ATC code at this level, e.g. \"N02\".",
+        "type": "string"
+      },
+      "description": {
+        "description": "WHO ATC name at this level, e.g. \"Analgesics\".",
+        "type": "string"
+      }
+    },
+    "required": [
+      "code",
+      "description"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -[
-  "code",
-  "description"
-]New value: +[
+  "code",
+  "description",
+  "levels"
+]

Previous value: -"True when this response is not the whole picture: a compound has further synonyms or descriptions past this page, or CIDs were skipped by the per-call fan-out limit. Per-compound totals are in compounds[].synonymsTotal / compounds[].descriptionsTotal; the skipped CIDs are in skippedCids."New value: +"True when this response is not the whole picture: a compound has further synonyms or descriptions past this page, CIDs were skipped by the per-call fan-out limit, or CIDs past the per-call cap were left unfetched. Per-compound totals are in compounds[].synonymsTotal / compounds[].descriptionsTotal; the skipped CIDs are in skippedCids, the unfetched ones in unprocessed."

Added value: +{
+  "description": "CIDs past the per-call cap of 100, in input order, not fetched. Pass them in a follow-up call. Omitted when every CID was fetched.",
+  "items": {
+    "type": "number"
+  },
+  "type": "array"
+}

Previous value: -9007199254740991New value: +2147483647

Previous value: -9007199254740991New value: +2147483647

Previous value: -"Interaction kinds to fetch. \"drug-drug\" (interactions with other drugs), \"drug-food\" (dietary interactions), \"target\" (binding/activity against molecular targets). Default: [\"drug-drug\"]."New value: +"Interaction kinds to fetch. \"drug-drug\" (interactions with other drugs), \"drug-food\" (dietary interactions), \"target\" (binding/activity against molecular targets). \"drug-drug\" and \"target\" come from PubChem's SDQ service, which can refuse automated requests; \"drug-food\" comes from PUG View. Per-target activity is also available from pubchem_get_bioactivity. Default: [\"drug-drug\"]."

Previous value: -"Max entries per kind per page (1-50). Well-studied drugs have a long tail of interactions; use offset to reach the ones past this page. Default: 10."New value: +"Max entries per kind per page. The per-call cap is 50: a larger value (up to 1000) reads a page of 50 per kind and is reported in cappedInputs. Well-studied drugs have a long tail of interactions; use offset to reach the ones past this page. Default: 10."

Previous value: -50New value: +1000

Added value: +{
+  "description": "Inputs that asked for more than their per-call cap, with the value requested and the value served. An ID batch lists the IDs past the cap in unprocessed. Omitted when every input was within its cap.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One input served at its per-call cap.",
+    "properties": {
+      "input": {
+        "description": "Input name, e.g. \"maxResults\" or \"cids\".",
+        "type": "string"
+      },
+      "requested": {
+        "description": "Value requested: the page size, or the number of IDs in the batch.",
+        "type": "number"
+      },
+      "served": {
+        "description": "Value served: the per-call cap.",
+        "type": "number"
+      },
+      "unprocessed": {
+        "description": "ID batches only: IDs past the cap, listed in unprocessed in input order.",
+        "type": "number"
+      }
+    },
+    "required": [
+      "input",
+      "requested",
+      "served"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Interaction kinds that could not be retrieved (comma-separated). The returned entries cover the kinds that succeeded; retry to re-attempt the failed ones."New value: +"Interaction kinds that could not be retrieved (comma-separated). The returned entries cover the kinds that succeeded. The notice says, per failed kind, whether a retry can help: a timeout or upstream error can clear, while a refusal from PubChem's SDQ service (drug-drug, target) does not."

Previous value: -"PubChem Compound IDs to fetch safety data for (1-25). Resolve from names/SMILES with pubchem_search_compounds."New value: +"PubChem Compound IDs to fetch safety data for. The per-call cap is 25: the first 25 are looked up, and any past that (up to 1000 in all) are returned in unprocessed, in input order, and reported in cappedInputs. Resolve from names/SMILES with pubchem_search_compounds."

Previous value: -9007199254740991New value: +2147483647

Previous value: -25New value: +1000

Added value: +{
+  "description": "Inputs that asked for more than their per-call cap, with the value requested and the value served. An ID batch lists the IDs past the cap in unprocessed. Omitted when every input was within its cap.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One input served at its per-call cap.",
+    "properties": {
+      "input": {
+        "description": "Input name, e.g. \"maxResults\" or \"cids\".",
+        "type": "string"
+      },
+      "requested": {
+        "description": "Value requested: the page size, or the number of IDs in the batch.",
+        "type": "number"
+      },
+      "served": {
+        "description": "Value served: the per-call cap.",
+        "type": "number"
+      },
+      "unprocessed": {
+        "description": "ID batches only: IDs past the cap, listed in unprocessed in input order.",
+        "type": "number"
+      }
+    },
+    "required": [
+      "input",
+      "requested",
+      "served"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Recovery guidance when one or more CIDs returned no GHS data, listing the unrecognized CIDs to verify separately from the CIDs that exist but carry no deposited classification."New value: +"Guidance when one or more CIDs returned no hazard classification, listing the unrecognized CIDs to verify, the CIDs that exist but carry no deposited classification, and the CIDs whose only classifications are \"Not Classified\" verdicts, each separately."

Previous value: -"CIDs requested."New value: +"CIDs requested, including any past the per-call cap left in unprocessed."

Previous value: -"Safety results, one per requested CID (input order preserved)."New value: +"Safety results, one per CID looked up (input order preserved). CIDs past the per-call cap are in unprocessed instead."

Added value: +{
+  "description": "Each source's classification in PubChem's order — EU harmonised, the ECHA C&L aggregate, single-company ECHA notifications, NITE-CMC revisions, and others. Sources can disagree; the top-level fields merge them.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One source's GHS classification, kept whole.",
+    "properties": {
+      "hazardCodes": {
+        "description": "Hazard codes this classification assigns. Empty for a \"Not Classified\" verdict.",
+        "items": {
+          "additionalProperties": false,
+          "description": "Hazard code assigned by this classification.",
+          "properties": {
+            "agreement": {
+              "description": "Share of notifying companies that assigned this code, exactly as PubChem prints it (e.g. \"37.7%\", \"> 99.9%\"). Present only where PubChem prints one beside the code, which is ECHA C&L classifications; read it against \"notifications\" — a single-company notification reports 100%.",
+              "type": "string"
+            },
+            "code": {
+              "description": "H-code (e.g. \"H319\"). Statement text is in the top-level hazardStatements.",
+              "type": "string"
+            }
+          },
+          "required": [
+            "code"
+          ],
+          "type": "object"
+        },
+        "type": "array"
+      },
+      "notClassified": {
+        "description": "True when this classification is ECHA's \"Not Classified\" verdict: notifiers assessed the compound and found it meets no GHS hazard criteria. Omitted otherwise.",
+        "type": "boolean"
+      },
+      "notifications": {
+        "description": "Notifier counts behind an ECHA classification: the first line of ECHA's C&L notifications summary (e.g. \"Aggregated GHS information provided per 13886 reports by companies from 79 notifications…\"), or for a \"Not Classified\" verdict the verdict line (e.g. \"Reported as not meeting GHS hazard criteria by 188 of 203 companies…\"). Omitted for sources that deposit no counts.",
+        "type": "string"
+      },
+      "pictograms": {
+        "description": "This classification's pictogram labels.",
+        "items": {
+          "type": "string"
+        },
+        "type": "array"
+      },
+      "signalWord": {
+        "description": "This classification's signal word. Omitted when the source assigns none.",
+        "type": "string"
+      },
+      "source": {
+        "description": "Depositing source (e.g. \"European Chemicals Agency (ECHA)\", \"NITE-CMC\"). Omitted when PubChem names no reference for the classification.",
+        "type": "string"
+      },
+      "sourceRecord": {
+        "description": "The source's own record title (e.g. \"Ethanol - FY2013 (Revised classification)\", \"Ethanol (EC: 200-578-6)\"). Tells revisions of one source, and the ECHA C&L aggregate from single-company ECHA notifications, apart.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "pictograms",
+      "hazardCodes"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"GHS hazard statements."New value: +"GHS hazard statements, union across classifications. A code here may come from a single source — see classifications for which source assigned it and with what notifier agreement."

Previous value: -"GHS pictogram labels (e.g. \"Flammable\", \"Toxic\")."New value: +"GHS pictogram labels (e.g. \"Flammable\", \"Acute Toxic\"), union across classifications."

Previous value: -"GHS precautionary statements."New value: +"GHS precautionary statements, union across classifications."

Previous value: -"GHS signal word: \"Danger\" or \"Warning\"."New value: +"GHS signal word, \"Danger\" or \"Warning\": the most severe any classification assigns. Omitted when none assigns one."

Previous value: -[
-  "pictograms",
-  "hazardStatements",
-  "precautionaryStatements"
-]New value: +[
+  "pictograms",
+  "hazardStatements",
+  "precautionaryStatements",
+  "classifications"
+]

Previous value: -"Whether GHS safety data is available for this compound."New value: +"Whether a GHS classification is on file for this compound (status \"ok\" or \"not_classified\"); \"ghs\" is present exactly when this is true."

Previous value: -"Data source attribution."New value: +"Sources that deposited a GHS classification, in PubChem's order, joined with \"; \"."

Previous value: -"Outcome for this CID. \"ok\": GHS data returned. \"no_ghs_data\": the compound exists in PubChem but has no deposited GHS classification. \"cid_not_found\": PubChem has no record for this CID at all — the identifier is wrong, so verify it with pubchem_search_compounds rather than concluding the compound is unclassified."New value: +"Outcome for this CID. \"ok\": GHS hazard classification returned. \"not_classified\": every deposited classification is an ECHA \"Not Classified\" verdict — notifiers assessed the compound and found it meets no GHS hazard criteria; the verdicts and their notifier counts are in ghs.classifications. \"no_ghs_data\": the compound exists in PubChem but has no deposited GHS classification. \"cid_not_found\": PubChem has no record for this CID at all — the identifier is wrong, so verify it with pubchem_search_compounds rather than concluding the compound is unclassified."

Previous value: -[
-  "ok",
-  "no_ghs_data",
-  "cid_not_found"
-]New value: +[
+  "ok",
+  "not_classified",
+  "no_ghs_data",
+  "cid_not_found"
+]

Added value: +{
+  "description": "CIDs past the per-call cap of 25, in input order, not looked up. Pass them in a follow-up call. Omitted when every CID was looked up.",
+  "items": {
+    "type": "number"
+  },
+  "type": "array"
+}

Previous value: -"CIDs with GHS safety data available."New value: +"CIDs with a GHS classification on file (status \"ok\" or \"not_classified\")."

Previous value: -9007199254740991New value: +2147483647

Previous value: -"Max IDs to return per xref type per page (1-500). A compound may have thousands of PubMed references; use offset to reach the ones past this page. Total count always reported. Default: 50."New value: +"Max IDs to return per xref type per page. The per-call cap is 500: a larger value (up to 1000) returns 500 per type and is reported in cappedInputs. A compound may have thousands of PubMed references; use offset to reach the ones past this page. Total count always reported. Default: 50."

Previous value: -500New value: +1000

Added value: +{
+  "description": "Inputs that asked for more than their per-call cap, with the value requested and the value served. An ID batch lists the IDs past the cap in unprocessed. Omitted when every input was within its cap.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One input served at its per-call cap.",
+    "properties": {
+      "input": {
+        "description": "Input name, e.g. \"maxResults\" or \"cids\".",
+        "type": "string"
+      },
+      "requested": {
+        "description": "Value requested: the page size, or the number of IDs in the batch.",
+        "type": "number"
+      },
+      "served": {
+        "description": "Value served: the per-call cap.",
+        "type": "number"
+      },
+      "unprocessed": {
+        "description": "ID batches only: IDs past the cap, listed in unprocessed in input order.",
+        "type": "number"
+      }
+    },
+    "required": [
+      "input",
+      "requested",
+      "served"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Cross-reference IDs on this page (window of offset + maxPerType)."New value: +"Cross-reference IDs on this page (window of offset + maxPerType). PubMedID is sorted numerically descending, so page one holds the highest, most recently assigned PMIDs; GeneID, ProteinGI and TaxonomyID numerically ascending; RegistryID, RN and PatentID keep PubChem's order."

Previous value: -"Entity identifiers (1-10). Type depends on entityType:\n- assay: AID (number), e.g. [1000]\n- gene: Gene ID (number), e.g. [1956]\n- protein: UniProt accession (string), e.g. [\"P00533\"]\n- taxonomy: Tax ID (number), e.g. [9606]"New value: +"Entity identifiers. A comma-joined string is split into one identifier per piece, with whitespace trimmed. The per-call cap is 10 pieces: the first 10 are looked up, and any past that are returned in unprocessed, in input order, and reported in cappedInputs. More than 1000 pieces in all fails the call. ID form depends on entityType:\n- assay: AID, a positive integer, e.g. [\"1000\"]\n- gene: NCBI Gene ID, a positive integer, e.g. [\"1956\"]\n- protein: UniProt accession, e.g. [\"P00533\"]\n- taxonomy: NCBI Taxonomy ID, a positive integer, e.g. [\"9606\"]\nFor assay, gene, and taxonomy, a piece that is not a positive integer written in digits is marked invalid and not looked up."

Removed value: -[
-  {
-    "description": "String identifier (e.g. UniProt accession).",
-    "type": "string"
-  },
-  {
-    "description": "Numeric identifier (e.g. AID, Gene ID, Tax ID).",
-    "type": "number"
-  }
-]

Previous value: -"Entity identifier — string or number depending on entityType."New value: +"Entity identifier, or several joined with commas."

Added value: +"string"

Previous value: -10New value: +1000

Added value: +{
+  "description": "Inputs that asked for more than their per-call cap, with the value requested and the value served. An ID batch lists the IDs past the cap in unprocessed. Omitted when every input was within its cap.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One input served at its per-call cap.",
+    "properties": {
+      "input": {
+        "description": "Input name, e.g. \"maxResults\" or \"cids\".",
+        "type": "string"
+      },
+      "requested": {
+        "description": "Value requested: the page size, or the number of IDs in the batch.",
+        "type": "number"
+      },
+      "served": {
+        "description": "Value served: the per-call cap.",
+        "type": "number"
+      },
+      "unprocessed": {
+        "description": "ID batches only: IDs past the cap, listed in unprocessed in input order.",
+        "type": "number"
+      }
+    },
+    "required": [
+      "input",
+      "requested",
+      "served"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Machine-readable failure mode."New value: +"Machine-readable failure mode. Declared by this tool: `too_many_identifiers`: Comma splitting yields more than 1000 identifier pieces. `invalid_identifier`: No identifier piece is usable: every piece is blank, or, for assay, gene, or taxonomy, not a positive integer. Other values are possible when a failure originates below the handler."

Added value: +[
+  "too_many_identifiers",
+  "invalid_identifier"
+]

Previous value: -"Recovery guidance when one or more identifiers were not found."New value: +"Recovery guidance when identifiers were invalid or not found."

Previous value: -"Identifiers requested."New value: +"Identifier pieces requested, counted after comma splitting."

Previous value: -"Summary results."New value: +"Summary results, one per identifier piece looked up, in input order."

Added value: +{
+  "description": "Date the assay's data last changed, YYYY-MM-DD (assay summaries).",
+  "type": "string"
+}

Added value: +{
+  "description": "Assay method as PubChem labels it, e.g. \"confirmatory\" (dose-response) or \"screening\" (assay summaries). Omitted when PubChem records none.",
+  "type": "string"
+}

Added value: +{
+  "description": "Compounds (CIDs) the assay marked active (assay summaries).",
+  "type": "number"
+}

Added value: +{
+  "description": "Compounds (CIDs) tested (assay summaries). List them with pubchem_search_compounds searchType \"assay\" and activeOnly: false — its default lists only the actives.",
+  "type": "number"
+}

Added value: +{
+  "description": "Number of targets PubChem lists for the assay (assay summaries).",
+  "type": "number"
+}

Added value: +{
+  "description": "Assay targets, the first 25 PubChem lists (assay summaries); targetCount gives the full number.",
+  "items": {
+    "additionalProperties": false,
+    "description": "Assay target.",
+    "properties": {
+      "accession": {
+        "description": "Target protein or gene accession.",
+        "type": "string"
+      },
+      "name": {
+        "description": "Target name.",
+        "type": "string"
+      }
+    },
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Queried identifier."New value: +"Queried identifier: a number for assay, gene, and taxonomy; the accession for protein; the piece as sent when invalid."

Added value: +{
+  "description": "True when the identifier is not in the form entityType expects; it was not looked up. Omitted otherwise.",
+  "type": "boolean"
+}

Added value: +{
+  "description": "Identifier pieces past the per-call cap of 10, in input order, not looked up. Pass them in a follow-up call. Omitted when every piece was served.",
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

Previous value: -"Max AIDs to return per page (1-200). Popular targets may have thousands of assays; use offset to reach the ones past this page. Default: 50."New value: +"Max AIDs to return per page. The per-call cap is 200: a larger value (up to 1000) returns a page of 200 and is reported in cappedInputs. Popular targets may have thousands of assays; use offset to reach the ones past this page. Default: 50."

Previous value: -200New value: +1000

Previous value: -"Target identifier. Examples: \"EGFR\" (genesymbol), \"Epidermal growth factor receptor\" (proteinname), \"1956\" (geneid), \"P00533\" (proteinaccession)."New value: +"Target identifier. Examples: \"EGFR\" (genesymbol), \"Epidermal growth factor receptor\" (proteinname), \"1956\" (geneid), \"P00533\" (proteinaccession; uppercased before lookup, except a PDB chain ID such as the \"A\" in \"1ZHH_A\", which is kept as given)."

Previous value: -"The maxResults cap that was applied."New value: +"The page size applied: maxResults, or the per-call cap when maxResults exceeds it."

Added value: +{
+  "description": "Inputs that asked for more than their per-call cap, with the value requested and the value served. An ID batch lists the IDs past the cap in unprocessed. Omitted when every input was within its cap.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One input served at its per-call cap.",
+    "properties": {
+      "input": {
+        "description": "Input name, e.g. \"maxResults\" or \"cids\".",
+        "type": "string"
+      },
+      "requested": {
+        "description": "Value requested: the page size, or the number of IDs in the batch.",
+        "type": "number"
+      },
+      "served": {
+        "description": "Value served: the per-call cap.",
+        "type": "number"
+      },
+      "unprocessed": {
+        "description": "ID batches only: IDs past the cap, listed in unprocessed in input order.",
+        "type": "number"
+      }
+    },
+    "required": [
+      "input",
+      "requested",
+      "served"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_target_query`: targetQuery is empty or whitespace-only. `invalid_geneid_query`: targetType is \"geneid\" but targetQuery is not a positive integer. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_target_query`: targetQuery is empty or whitespace-only. `invalid_geneid_query`: targetType is \"geneid\" but targetQuery contains characters other than digits. Other values are possible when a failure originates below the handler."

Added value: +{
+  "default": true,
+  "description": "Assay search only. When true (default), lists only the compounds the assay marked active; false lists every compound it tested.",
+  "type": "boolean"
+}

Added value: +{
+  "description": "Required for assay search. PubChem Assay ID (AID) whose compounds to list, from 1 to 2147483647, e.g. 1000. Find AIDs for a biological target with pubchem_search_assays.",
+  "maximum": 2147483647,
+  "minimum": 1,
+  "type": "integer"
+}

Previous value: -"Required for identifier search. Array of identifiers to resolve (1-25). Examples: [\"aspirin\", \"ibuprofen\"] for name, [\"CC(=O)OC1=CC=CC=C1C(=O)O\"] for SMILES, [\"BSYNRYMUTXBXSQ-UHFFFAOYSA-N\"] for inchikey (27-char block format)."New value: +"Required for identifier search. Array of identifiers to resolve. The per-call cap is 25: the first 25 are looked up, and any past that (up to 1000 in all) are returned in unprocessed, in input order, and reported in cappedInputs. Examples: [\"aspirin\", \"ibuprofen\"] for name, [\"CC(=O)OC1=CC=CC=C1C(=O)O\"] for SMILES, [\"BSYNRYMUTXBXSQ-UHFFFAOYSA-N\"] for inchikey (27-char block format; uppercased before lookup, any case accepted)."

Previous value: -25New value: +1000

Previous value: -"Maximum CIDs to return per page (1-200). Use offset to reach matches past this page. Default: 20."New value: +"Maximum CIDs to return per page. The per-call cap is 200: a larger value (up to 1000) returns a page of 200 and is reported in cappedInputs. Use offset to reach matches past this page. Default: 20."

Previous value: -200New value: +1000

Previous value: -"Zero-based index of the first CID to return. Pass the nextOffset from a previous call to read the following page. Identifier lookups resolve every match up front, so paging them is free; formula, substructure, superstructure, and similarity searches have to ask PubChem for offset + maxResults records to reach a page, so deep pages cost progressively more upstream — hence the 10000 ceiling. Default: 0."New value: +"Zero-based index of the first CID to return. Pass the nextOffset from a previous call to read the following page. Identifier lookups resolve every match up front, so paging them is free, and assay searches fetch only the requested page; formula, substructure, superstructure, and similarity searches have to ask PubChem for offset + maxResults records to reach a page, so deep pages cost progressively more upstream — hence the 10000 ceiling. Default: 0."

Previous value: -"Required for substructure/superstructure/similarity searches. A SMILES string (e.g. \"CC(=O)O\") or PubChem CID as a string (e.g. \"2244\")."New value: +"Required for substructure/superstructure/similarity searches. A SMILES string (e.g. \"CC(=O)O\") or PubChem CID as a string from 1 to 2147483647 (e.g. \"2244\")."

Previous value: -"Search strategy; each mode needs its own fields. \"identifier\": name/SMILES/InChIKey lookup — requires identifierType and identifiers. \"formula\": molecular formula — requires formula. \"substructure\": find compounds containing the query as a substructure. \"superstructure\": find compounds that are themselves substructures of the query. \"similarity\": 2D Tanimoto similarity to the query. substructure, superstructure, and similarity require query and queryType."New value: +"Search strategy; each mode needs its own fields. \"identifier\": name/SMILES/InChIKey lookup — requires identifierType and identifiers. \"formula\": molecular formula — requires formula. \"substructure\": find compounds containing the query as a substructure. \"superstructure\": find compounds that are themselves substructures of the query. \"similarity\": 2D Tanimoto similarity to the query. substructure, superstructure, and similarity require query and queryType. \"assay\": compounds tested in a PubChem bioassay — requires aid; activeOnly (default true) keeps only the compounds the assay marked active."

Previous value: -[
-  "identifier",
-  "formula",
-  "substructure",
-  "superstructure",
-  "similarity"
-]New value: +[
+  "identifier",
+  "formula",
+  "substructure",
+  "superstructure",
+  "similarity",
+  "assay"
+]

Added value: +{
+  "description": "Assay search only: true when the list holds only the compounds the assay marked active, false when it holds every compound tested.",
+  "type": "boolean"
+}

Previous value: -"The maxResults cap that was applied."New value: +"The page size applied: maxResults, or the per-call cap when maxResults exceeds it."

Added value: +{
+  "description": "Inputs that asked for more than their per-call cap, with the value requested and the value served. An ID batch lists the IDs past the cap in unprocessed. Omitted when every input was within its cap.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One input served at its per-call cap.",
+    "properties": {
+      "input": {
+        "description": "Input name, e.g. \"maxResults\" or \"cids\".",
+        "type": "string"
+      },
+      "requested": {
+        "description": "Value requested: the page size, or the number of IDs in the batch.",
+        "type": "number"
+      },
+      "served": {
+        "description": "Value served: the per-call cap.",
+        "type": "number"
+      },
+      "unprocessed": {
+        "description": "ID batches only: IDs past the cap, listed in unprocessed in input order.",
+        "type": "number"
+      }
+    },
+    "required": [
+      "input",
+      "requested",
+      "served"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted or blank. `missing_structure_args`: substructure/superstructure/similarity search with query or queryType omitted, or a blank query. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not a positive integer CID. `identifier_rejected`: identifier search where PubChem rejected every identifier in the batch as unreadable (HTTP 400) — for SMILES, a string it could not standardize into a structure. A batch with any other outcome lists rejected inputs in unresolvedIdentifiers instead. `search_query_rejected`: PubChem failed a formula, substructure, superstructure, or similarity search with HTTP 500 \"Search status indicates failure\" — its answer for a malformed SMILES or formula, a SMILES with a \"*\" wildcard atom, or a CID with no record. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted or blank. `missing_structure_args`: substructure/superstructure/similarity search with query or queryType omitted, or a blank query. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not an integer CID from 1 to 2147483647. `missing_aid`: searchType is \"assay\" but aid was omitted. `aid_not_found`: assay search where PubChem has no live assay with the given AID. `identifier_rejected`: identifier search where PubChem rejected every identifier in the batch as unreadable (HTTP 400) — for SMILES, a string it could not standardize into a structure. A batch with any other outcome lists rejected inputs in unresolvedIdentifiers instead. `search_query_rejected`: PubChem failed a formula, substructure, superstructure, or similarity search with HTTP 500 \"Search status indicates failure\" — its answer for a malformed SMILES or formula, a SMILES with a \"*\" wildcard atom, or a CID with no record. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "missing_identifier_args",
-  "missing_formula",
-  "missing_structure_args",
-  "invalid_cid_query",
-  "identifier_rejected",
-  "search_query_rejected"
-]New value: +[
+  "missing_identifier_args",
+  "missing_formula",
+  "missing_structure_args",
+  "invalid_cid_query",
+  "missing_aid",
+  "aid_not_found",
+  "identifier_rejected",
+  "search_query_rejected"
+]

Previous value: -"Recovery guidance when no compounds matched, when the offset runs past the matches observed, when identifiers had no match or could not be interpreted, when identifiers collided on one CID, or when further pages remain. Absent when this page is complete and every identifier resolved to its own CID."New value: +"Recovery guidance when no compounds matched (for an assay search, when the assay recorded none of the requested kind), when the offset runs past the matches observed, when identifiers had no match or could not be interpreted, when identifiers collided on one CID, or when further pages remain. Absent when this page is complete and every identifier resolved to its own CID."

Previous value: -"Search strategy used: identifier, formula, substructure, superstructure, or similarity."New value: +"Search strategy used: identifier, formula, substructure, superstructure, similarity, or assay."

Added value: +{
+  "description": "Identifier-mode only: identifiers past the per-call cap of 25, in input order, not looked up. Pass them in a follow-up call. Omitted when every identifier was looked up.",
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Removed value: -0

Added value: +1

Previous value: -"Search strategy. \"identifier\": name/SMILES/InChIKey lookup. \"formula\": molecular formula. \"substructure\": find compounds containing the query as a substructure. \"superstructure\": find compounds that are themselves substructures of the query. \"similarity\": 2D Tanimoto similarity to the query."New value: +"Search strategy; each mode needs its own fields. \"identifier\": name/SMILES/InChIKey lookup — requires identifierType and identifiers. \"formula\": molecular formula — requires formula. \"substructure\": find compounds containing the query as a substructure. \"superstructure\": find compounds that are themselves substructures of the query. \"similarity\": 2D Tanimoto similarity to the query. substructure, superstructure, and similarity require query and queryType."

Previous value: -"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted. `missing_structure_args`: substructure/superstructure/similarity search missing query or queryType. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not a positive integer CID. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted or blank. `missing_structure_args`: substructure/superstructure/similarity search with query or queryType omitted, or a blank query. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not a positive integer CID. `identifier_rejected`: identifier search where PubChem rejected every identifier in the batch as unreadable (HTTP 400) — for SMILES, a string it could not standardize into a structure. A batch with any other outcome lists rejected inputs in unresolvedIdentifiers instead. `search_query_rejected`: PubChem failed a formula, substructure, superstructure, or similarity search with HTTP 500 \"Search status indicates failure\" — its answer for a malformed SMILES or formula, a SMILES with a \"*\" wildcard atom, or a CID with no record. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "missing_identifier_args",
-  "missing_formula",
-  "missing_structure_args",
-  "invalid_cid_query"
-]New value: +[
+  "missing_identifier_args",
+  "missing_formula",
+  "missing_structure_args",
+  "invalid_cid_query",
+  "identifier_rejected",
+  "search_query_rejected"
+]

Previous value: -"Recovery guidance when no compounds matched, when the offset runs past the matches observed, when identifiers failed to resolve, or when further pages remain. Absent when this page is complete and every identifier resolved."New value: +"Recovery guidance when no compounds matched, when the offset runs past the matches observed, when identifiers had no match or could not be interpreted, when identifiers collided on one CID, or when further pages remain. Absent when this page is complete and every identifier resolved to its own CID."

Previous value: -"Identifier-mode only: input identifiers that resolved to no CID. Omitted when every identifier resolved and for non-identifier searches."New value: +"Identifier-mode only: input identifiers that resolved to no CID — PubChem had no match, or could not interpret the input as identifierType (the notice says which). Omitted when every identifier resolved and for non-identifier searches."

Previous value: -"Machine-readable failure mode. Declared by this tool: `no_3d_structure`: PubChem has no computed 3D conformer for the requested CID Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `no_3d_structure`: PubChem has no computed 3D conformer for the requested CID. Other values are possible when a failure originates below the handler."

Previous value: -"Machine-readable failure mode. Declared by this tool: `cid_not_found`: PubChem returned 404 for the requested CID Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `cid_not_found`: PubChem returned 404 for the requested CID. Other values are possible when a failure originates below the handler."

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_target_query`: targetQuery is empty or whitespace-only `invalid_geneid_query`: targetType is \"geneid\" but targetQuery is not a positive integer Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_target_query`: targetQuery is empty or whitespace-only. `invalid_geneid_query`: targetType is \"geneid\" but targetQuery is not a positive integer. Other values are possible when a failure originates below the handler."

Previous value: -"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted `missing_formula`: searchType is \"formula\" but the formula field was omitted `missing_structure_args`: substructure/superstructure/similarity search missing query or queryType `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not a positive integer CID Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted. `missing_formula`: searchType is \"formula\" but the formula field was omitted. `missing_structure_args`: substructure/superstructure/similarity search missing query or queryType. `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not a positive integer CID. Other values are possible when a failure originates below the handler."

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "boolean",
+  "null"
+]

Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "number",
+  "null"
+]

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "boolean",
+  "null"
+]

Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "number",
+  "null"
+]

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "boolean",
+  "null"
+]

Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "number",
+  "null"
+]

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "boolean",
+  "null"
+]

Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "number",
+  "null"
+]

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "boolean",
+  "null"
+]

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "boolean",
+  "null"
+]

Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "number",
+  "null"
+]

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "boolean",
+  "null"
+]

Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "number",
+  "null"
+]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "cid",
+      "totalAssays",
+      "activeCount",
+      "inactiveCount",
+      "results",
+      "outcomeFilter",
+      "filteredCount",
+      "returnedCount",
+      "offset"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode.",
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Removed value: -[
-  "cid",
-  "totalAssays",
-  "activeCount",
-  "inactiveCount",
-  "results",
-  "outcomeFilter",
-  "filteredCount",
-  "returnedCount",
-  "offset"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "cid",
+      "atomCount",
+      "bondCount"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode. Declared by this tool: `no_3d_structure`: PubChem has no computed 3D conformer for the requested CID Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "no_3d_structure"
+          ],
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Removed value: -[
-  "cid",
-  "atomCount",
-  "bondCount"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "compounds",
+      "truncated"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode.",
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Added value: +{
+  "description": "True when this response is not the whole picture: a compound has further synonyms or descriptions past this page, or CIDs were skipped by the per-call fan-out limit. Per-compound totals are in compounds[].synonymsTotal / compounds[].descriptionsTotal; the skipped CIDs are in skippedCids.",
+  "type": "boolean"
+}

Removed value: -[
-  "compounds"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "cid",
+      "imageBase64",
+      "mimeType",
+      "width",
+      "height"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode. Declared by this tool: `cid_not_found`: PubChem returned 404 for the requested CID Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "cid_not_found"
+          ],
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Removed value: -[
-  "cid",
-  "imageBase64",
-  "mimeType",
-  "width",
-  "height"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "cid",
+      "entries",
+      "paging",
+      "requestedKinds",
+      "returnedCount",
+      "truncated",
+      "offset"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode.",
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Added value: +{
+  "description": "True when at least one requested kind has source records remaining past this page. Which kinds, and how many records each holds, is in paging[].truncated / paging[].totalRecords.",
+  "type": "boolean"
+}

Removed value: -[
-  "cid",
-  "entries",
-  "paging",
-  "requestedKinds",
-  "returnedCount",
-  "offset"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "results",
+      "requestedCount",
+      "withDataCount"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode.",
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Removed value: -[
-  "results",
-  "requestedCount",
-  "withDataCount"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "cid",
+      "xrefs",
+      "offset",
+      "truncated"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode.",
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Added value: +{
+  "description": "True when at least one requested type has IDs remaining past this page. Which types, and how many IDs each holds in total, is in xrefs[].truncated / xrefs[].totalAvailable.",
+  "type": "boolean"
+}

Removed value: -[
-  "cid",
-  "xrefs",
-  "offset"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "entityType",
+      "summaries",
+      "requestedCount",
+      "foundCount"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode.",
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Removed value: -[
-  "entityType",
-  "summaries",
-  "requestedCount",
-  "foundCount"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "aids",
+      "targetType",
+      "targetQuery",
+      "totalFound",
+      "offset"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode. Declared by this tool: `blank_target_query`: targetQuery is empty or whitespace-only `invalid_geneid_query`: targetType is \"geneid\" but targetQuery is not a positive integer Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "blank_target_query",
+            "invalid_geneid_query"
+          ],
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Removed value: -[
-  "aids",
-  "targetType",
-  "targetQuery",
-  "totalFound",
-  "offset"
-]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "results",
+      "searchType",
+      "offset"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode. Declared by this tool: `missing_identifier_args`: searchType is \"identifier\" but identifierType or identifiers were omitted `missing_formula`: searchType is \"formula\" but the formula field was omitted `missing_structure_args`: substructure/superstructure/similarity search missing query or queryType `invalid_cid_query`: structure/similarity search with queryType \"cid\" but query is not a positive integer CID Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "missing_identifier_args",
+            "missing_formula",
+            "missing_structure_args",
+            "invalid_cid_query"
+          ],
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Removed value: -[
-  "results",
-  "searchType",
-  "offset"
-]

Previous value: -"Max assay results to return (1-100). Well-studied compounds have thousands of records. Default: 20."New value: +"Max assay results to return per page (1-100). Well-studied compounds have thousands of records; use offset to reach the ones past this page. Default: 20."

Previous value: -"number"New value: +"integer"

Added value: +{
+  "default": 0,
+  "description": "Zero-based index of the first assay to return, applied after the outcome and target filters. Pass the nextOffset from a previous call to read the following page. Default: 0.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Previous value: -"Assays matching the outcome and target filters, before the maxResults cap."New value: +"Exact number of assays matching the outcome and target filters, across all pages."

Added value: +{
+  "description": "Offset to pass on the next call to continue past this page. Omitted when no further assays match.",
+  "type": "number"
+}

Added value: +{
+  "description": "Zero-based index of the first assay returned.",
+  "type": "number"
+}

Previous value: -"Assays returned after the maxResults cap."New value: +"Assays returned on this page."

Previous value: -"Assays returned after the maxResults cap."New value: +"Assays returned on this page."

Previous value: -"True when results were capped at maxResults — more matching assays exist."New value: +"True when matching assays remain past this page."

Previous value: -[
-  "cid",
-  "totalAssays",
-  "activeCount",
-  "inactiveCount",
-  "results",
-  "outcomeFilter",
-  "filteredCount",
-  "returnedCount"
-]New value: +[
+  "cid",
+  "totalAssays",
+  "activeCount",
+  "inactiveCount",
+  "results",
+  "outcomeFilter",
+  "filteredCount",
+  "returnedCount",
+  "offset"
+]

Previous value: -"List the IDs of additional computed conformers beyond the default. Adds one extra API call. Default: false."New value: +"List the IDs of additional computed conformers beyond the default. Slower than the default response. Default: false."

Previous value: -"PubChem Compound IDs to fetch (1-100). Batched efficiently. Resolve from names/SMILES with pubchem_search_compounds."New value: +"PubChem Compound IDs to fetch (1-100). Resolve from names/SMILES with pubchem_search_compounds."

Added value: +{
+  "default": 0,
+  "description": "Zero-based index of the first description to return within each compound's description list. The same offset is applied to every compound in the batch. Pass the nextDescriptionOffset from a previous call to read the following page. Default: 0.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Previous value: -"Include pharmacological classification: FDA Established Pharmacologic Classes, mechanisms of action, MeSH classes, and ATC codes. Fetched only for the first 10 CIDs in the batch; remaining CIDs return without classification."New value: +"Include pharmacological classification: FDA Established Pharmacologic Classes, mechanisms of action, MeSH classes, and ATC codes. Fetched only for the first 10 CIDs in the batch; remaining CIDs return without classification and are listed in the response's skippedCids."

Previous value: -"Include textual descriptions (pharmacology, mechanism, therapeutic use) attributed by source. Well-studied compounds have many overlapping summaries — capped via maxDescriptions. Fetched only for the first 10 CIDs in the batch; remaining CIDs return without descriptions."New value: +"Include textual descriptions (pharmacology, mechanism, therapeutic use) attributed by source. Well-studied compounds have many overlapping summaries — paged via descriptionOffset/maxDescriptions. Fetched only for the first 10 CIDs in the batch; remaining CIDs return without descriptions and are listed in the response's skippedCids."

Previous value: -"Compute drug-likeness assessment: Lipinski Rule of Five (MW, XLogP, HBD, HBA) and Veber rules (TPSA, rotatable bonds). No extra API calls — computed from properties."New value: +"Compute drug-likeness assessment: Lipinski Rule of Five (MW, XLogP, HBD, HBA) and Veber rules (TPSA, rotatable bonds). Computed from the returned properties, so it adds no latency."

Previous value: -"Fetch all known names and synonyms (trade names, systematic names, registry numbers). One API call per CID — slower than the property batch for large CID lists."New value: +"Fetch known names and synonyms (trade names, systematic names, registry numbers), paged via synonymOffset/maxSynonyms. Fetched for every found CID in the batch. Slower for large CID lists."

Previous value: -"Max number of distinct description entries per compound (1-20). PubChem returns near-duplicate summaries from many depositors; we dedup and cap to keep responses focused. Default: 3."New value: +"Max number of distinct description entries per compound per page (1-20). PubChem returns near-duplicate summaries from many depositors; duplicates are collapsed before this cap applies. Default: 3."

Previous value: -"Max synonyms returned per compound (1-100). PubChem lists hundreds for common drugs; capped to keep the response focused. Default: 20."New value: +"Max synonyms returned per compound per page (1-100). PubChem lists hundreds for common drugs; use synonymOffset to reach the ones past this page. Default: 20."

Added value: +{
+  "default": 0,
+  "description": "Zero-based index of the first synonym to return within each compound's synonym list. The same offset is applied to every compound in the batch. Pass the nextSynonymOffset from a previous call to read the following page. Default: 0.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Previous value: -"Textual descriptions, deduplicated and capped at maxDescriptions. Each entry carries optional source attribution."New value: +"Textual descriptions on this page, deduplicated then windowed by descriptionOffset/maxDescriptions. Each entry carries optional source attribution. Empty when descriptionOffset runs past descriptionsTotal."

Previous value: -"Total distinct descriptions available before truncation. Larger than descriptions.length when more sources exist — increase maxDescriptions to see them."New value: +"Total distinct descriptions available for this compound, across all pages. Larger than descriptions.length when more sources exist — raise maxDescriptions or page with descriptionOffset to see them."

Previous value: -"Known names and synonyms."New value: +"Known names and synonyms on this page, windowed by synonymOffset/maxSynonyms. Empty when synonymOffset runs past synonymsTotal."

Previous value: -"Total synonyms available before truncation. Larger than synonyms.length when more exist — increase maxSynonyms to see them."New value: +"Total synonyms available for this compound, across all pages. Larger than synonyms.length when more exist — raise maxSynonyms or page with synonymOffset to see them."

Added value: +{
+  "description": "Zero-based index of the first description returned within each compound's list. Present when includeDescription is true.",
+  "type": "number"
+}

Added value: +{
+  "description": "CIDs whose descriptions and classification were fetched. Present only when the batch exceeded the per-call fan-out limit and other CIDs were skipped.",
+  "items": {
+    "type": "number"
+  },
+  "type": "array"
+}

Added value: +{
+  "description": "descriptionOffset to pass on the next call to continue past this page. Omitted when no compound in the batch has further descriptions.",
+  "type": "number"
+}

Added value: +{
+  "description": "synonymOffset to pass on the next call to continue past this page. Omitted when no compound in the batch has further synonyms.",
+  "type": "number"
+}

Added value: +{
+  "description": "Recovery guidance covering the skipped CIDs, an offset that runs past every compound, and pages that remain. Absent when nothing was skipped or truncated.",
+  "type": "string"
+}

Added value: +{
+  "description": "CIDs found in PubChem whose descriptions and classification were NOT fetched because the batch exceeded the per-call fan-out limit. Their absence from a record means \"not requested\", not \"PubChem has none\" — re-request these CIDs in a follow-up call. Present only when CIDs were skipped.",
+  "items": {
+    "type": "number"
+  },
+  "type": "array"
+}

Added value: +{
+  "description": "Zero-based index of the first synonym returned within each compound's list. Present when includeSynonyms is true.",
+  "type": "number"
+}

Previous value: -"Max entries per kind (1-50). Well-studied drugs have a long tail of interactions. Default: 10."New value: +"Max entries per kind per page (1-50). Well-studied drugs have a long tail of interactions; use offset to reach the ones past this page. Default: 10."

Added value: +{
+  "default": 0,
+  "description": "Zero-based start position within each requested kind, counted in source records rather than returned entries. The same offset applies to every kind in the call, and the kinds advance at different rates — when paging past the first page, request one kind per call and pass that kind's nextOffset. Default: 0.",
+  "maximum": 2147483646,
+  "minimum": 0,
+  "type": "integer"
+}

Removed value: -{
-  "description": "Raw severity as the source reports it — not normalized across sources, and frequently unset (most sources embed severity in the statement text).",
-  "type": "string"
-}

Added value: +{
+  "description": "Offset to pass on the next call, reported when exactly one requested kind has records remaining. Omitted when none do, and when several do — those advance to different positions, so read paging[].nextOffset instead.",
+  "type": "number"
+}

Previous value: -"Guidance when no interaction data was found for the requested kinds."New value: +"Guidance when a kind failed, when no interaction data was found, when the offset runs past every requested kind, or when further pages remain. Absent when this page is complete and every kind resolved."

Added value: +{
+  "description": "Zero-based start position read within each requested kind.",
+  "type": "number"
+}

Added value: +{
+  "description": "Per-kind page position, one entry per requested kind that was retrieved. A kind listed in failedKinds is absent — its position is unknown, not exhausted.",
+  "items": {
+    "additionalProperties": false,
+    "description": "Page position for one interaction kind.",
+    "properties": {
+      "kind": {
+        "description": "Interaction category this page covers.",
+        "enum": [
+          "drug-drug",
+          "drug-food",
+          "target"
+        ],
+        "type": "string"
+      },
+      "nextOffset": {
+        "description": "Offset to pass on the next call to continue this kind past the current page. Omitted when no records remain.",
+        "type": "number"
+      },
+      "returnedCount": {
+        "description": "Interaction entries returned for this kind.",
+        "type": "number"
+      },
+      "totalRecords": {
+        "description": "Source records available for this kind, across all pages. Entries are derived from these records and can be fewer: a \"target\" record naming no molecular target and a \"drug-drug\" record carrying no statement both yield nothing, and duplicate measurements collapse within a page. Pages divide the records, not the entries, so a duplicate split across two pages is reported on both.",
+        "type": "number"
+      },
+      "truncated": {
+        "description": "True when source records remain for this kind past the current page.",
+        "type": "boolean"
+      }
+    },
+    "required": [
+      "kind",
+      "returnedCount",
+      "totalRecords",
+      "truncated"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Previous value: -[
-  "cid",
-  "entries",
-  "requestedKinds",
-  "returnedCount"
-]New value: +[
+  "cid",
+  "entries",
+  "paging",
+  "requestedKinds",
+  "returnedCount",
+  "offset"
+]

Previous value: -"Cross-tool guidance when one or more CIDs have no GHS data, pointing to an alternative source."New value: +"Recovery guidance when one or more CIDs returned no GHS data, listing the unrecognized CIDs to verify separately from the CIDs that exist but carry no deposited classification."

Added value: +{
+  "description": "Whether \"statement\" carries the standard text. False for codes needing label-specific fill text the depositor must supply (disposal method, firefighting agent, first-aid reference) and for codes outside the decoder table; the code itself is still authoritative.",
+  "type": "boolean"
+}

Previous value: -"Precautionary statement text."New value: +"Standard precautionary statement text for the code. Empty string when \"decoded\" is false — PubChem deposits P-codes without text, so a blank statement means the code was not decoded, never that the depositor supplied an empty statement."

Previous value: -[
-  "code",
-  "statement"
-]New value: +[
+  "code",
+  "statement",
+  "decoded"
+]

Added value: +{
+  "description": "Outcome for this CID. \"ok\": GHS data returned. \"no_ghs_data\": the compound exists in PubChem but has no deposited GHS classification. \"cid_not_found\": PubChem has no record for this CID at all — the identifier is wrong, so verify it with pubchem_search_compounds rather than concluding the compound is unclassified.",
+  "enum": [
+    "ok",
+    "no_ghs_data",
+    "cid_not_found"
+  ],
+  "type": "string"
+}

Previous value: -[
-  "cid",
-  "hasData"
-]New value: +[
+  "cid",
+  "hasData",
+  "status"
+]

Previous value: -"Max IDs to return per xref type (1-500). A compound may have thousands of PubMed references. Total count always reported. Default: 50."New value: +"Max IDs to return per xref type per page (1-500). A compound may have thousands of PubMed references; use offset to reach the ones past this page. Total count always reported. Default: 50."

Previous value: -"number"New value: +"integer"

Added value: +{
+  "default": 0,
+  "description": "Zero-based index of the first ID to return within each xref type. The same offset is applied to every requested type. Pass the nextOffset from a previous call to read the following page. Default: 0.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Added value: +{
+  "description": "Offset to pass on the next call to continue past this page. Omitted when no requested type has further IDs.",
+  "type": "number"
+}

Previous value: -"Recovery guidance when every requested xref type returned zero IDs — hints to verify the CID. Absent when any cross-references were found."New value: +"Recovery guidance when every requested xref type returned zero IDs, when the offset runs past every type, or when further pages remain. Absent when this page is complete and non-empty."

Added value: +{
+  "description": "Zero-based index of the first ID returned within each type.",
+  "type": "number"
+}

Previous value: -"Cross-reference IDs (capped by maxPerType)."New value: +"Cross-reference IDs on this page (window of offset + maxPerType)."

Previous value: -"Total IDs available before truncation."New value: +"Total IDs available for this type, across all pages."

Previous value: -"Whether results were truncated."New value: +"True when IDs for this type remain past the current page."

Previous value: -[
-  "cid",
-  "xrefs"
-]New value: +[
+  "cid",
+  "xrefs",
+  "offset"
+]

Previous value: -"Parent taxonomy lineage (taxonomy summaries)."New value: +"Taxonomic lineage ordered from the most inclusive rank to the most specific, e.g. [\"Eukaryota\", \"Metazoa\", \"Chordata\"] (taxonomy summaries). Ranks that do not apply to the entity are omitted."

Previous value: -"Max AIDs to return (1-200). Popular targets may have thousands of assays. Default: 50."New value: +"Max AIDs to return per page (1-200). Popular targets may have thousands of assays; use offset to reach the ones past this page. Default: 50."

Previous value: -"number"New value: +"integer"

Added value: +{
+  "default": 0,
+  "description": "Zero-based index of the first AID to return. Pass the nextOffset from a previous call to read the following page. Default: 0.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Added value: +{
+  "description": "Offset to pass on the next call to continue past this page. Omitted when no further AIDs match.",
+  "type": "number"
+}

Previous value: -"Recovery guidance when no assays matched — echoes the target and suggests alternative search types. Absent when assays were returned."New value: +"Recovery guidance when no assays matched, when the offset runs past the result set, or when further pages remain. Absent when this page is complete and non-empty."

Added value: +{
+  "description": "Zero-based index of the first AID returned.",
+  "type": "number"
+}

Previous value: -"AIDs returned after the maxResults cap."New value: +"AIDs returned on this page."

Previous value: -"Total AIDs found before the maxResults cap."New value: +"Total AIDs found for this target, across all pages."

Previous value: -"True when AIDs were capped at maxResults — more assays exist than returned."New value: +"True when matching AIDs remain past this page."

Previous value: -[
-  "aids",
-  "targetType",
-  "targetQuery",
-  "totalFound"
-]New value: +[
+  "aids",
+  "targetType",
+  "targetQuery",
+  "totalFound",
+  "offset"
+]

Previous value: -"Maximum CIDs to return (1-200). Default: 20."New value: +"Maximum CIDs to return per page (1-200). Use offset to reach matches past this page. Default: 20."

Previous value: -"number"New value: +"integer"

Added value: +{
+  "default": 0,
+  "description": "Zero-based index of the first CID to return. Pass the nextOffset from a previous call to read the following page. Identifier lookups resolve every match up front, so paging them is free; formula, substructure, superstructure, and similarity searches have to ask PubChem for offset + maxResults records to reach a page, so deep pages cost progressively more upstream — hence the 10000 ceiling. Default: 0.",
+  "maximum": 10000,
+  "minimum": 0,
+  "type": "integer"
+}

Added value: +{
+  "description": "Offset to pass on the next call to continue past this page. Omitted when no further matches remain.",
+  "type": "number"
+}

Previous value: -"Recovery guidance when no compounds matched — echoes search strategy and suggests how to broaden. Absent when results were returned."New value: +"Recovery guidance when no compounds matched, when the offset runs past the matches observed, when identifiers failed to resolve, or when further pages remain. Absent when this page is complete and every identifier resolved."

Added value: +{
+  "description": "Zero-based index of the first CID returned.",
+  "type": "number"
+}

Previous value: -"CIDs returned after the maxResults cap."New value: +"CIDs returned on this page."

Previous value: -"Total CIDs found before the maxResults cap."New value: +"Exact number of matching CIDs across all pages. Omitted when a formula, substructure, superstructure, or similarity search saturated the records it requested — PubChem returns no match count for those, so totalFoundAtLeast reports a floor instead."

Added value: +{
+  "description": "Lower bound on matching CIDs, reported in place of totalFound when the exact count is unavailable. At least this many match, and the true total may be higher; page further with offset to observe more.",
+  "type": "number"
+}

Previous value: -"True when CIDs were capped at maxResults — more matches exist than returned."New value: +"True when matching CIDs remain past this page."

Previous value: -[
-  "results",
-  "searchType",
-  "totalFound"
-]New value: +[
+  "results",
+  "searchType",
+  "offset"
+]

Added value: +{
+  "default": false,
+  "description": "For format=\"sdf\", return the complete raw V2000 SDF even when it exceeds the safe line cap. Default false: an SDF longer than 500 lines is line-capped with disclosure. No effect when format=\"json\".",
+  "type": "boolean"
+}

Added value: +{
+  "description": "Cap the atoms returned in the format=\"json\" preview. atomCount always reports the full total; omitted rows are disclosed via the truncated/shownAtoms enrichment. Defaults to the first 200 atoms.",
+  "exclusiveMinimum": 0,
+  "maximum": 9007199254740991,
+  "type": "integer"
+}

Added value: +{
+  "description": "Cap the bonds returned in the format=\"json\" preview. bondCount always reports the full total; omitted rows are disclosed via the truncated/shownBonds enrichment. Defaults to the first 200 bonds.",
+  "exclusiveMinimum": 0,
+  "maximum": 9007199254740991,
+  "type": "integer"
+}

Added value: +{
+  "description": "The atom cap applied (explicit maxAtoms or the safe default), when the atom list was capped.",
+  "type": "number"
+}

Added value: +{
+  "description": "The bond cap applied (explicit maxBonds or the safe default), when the bond list was capped.",
+  "type": "number"
+}

Added value: +{
+  "description": "Guidance naming which lists were capped and how to widen them.",
+  "type": "string"
+}

Added value: +{
+  "description": "Atoms returned after the cap, when fewer than atomCount. Raise maxAtoms for more.",
+  "type": "number"
+}

Added value: +{
+  "description": "Bonds returned after the cap, when fewer than bondCount. Raise maxBonds for more.",
+  "type": "number"
+}

Added value: +{
+  "description": "SDF lines returned when format=\"sdf\" and the raw text was line-capped. Set includeRawSdf for the full record.",
+  "type": "number"
+}

Added value: +{
+  "description": "True when the atom list, bond list, or raw SDF was capped below its total. atomCount/bondCount always report the full totals.",
+  "type": "boolean"
+}

Added value: +{
+  "default": 20,
+  "description": "Max synonyms returned per compound (1-100). PubChem lists hundreds for common drugs; capped to keep the response focused. Default: 20.",
+  "maximum": 100,
+  "minimum": 1,
+  "type": "integer"
+}

Added value: +{
+  "description": "Total synonyms available before truncation. Larger than synonyms.length when more exist — increase maxSynonyms to see them.",
+  "type": "number"
+}

Added value: +{
+  "description": "Recovery guidance when every requested xref type returned zero IDs — hints to verify the CID. Absent when any cross-references were found.",
+  "type": "string"
+}

Added value: +{
+  "description": "Identifier-mode only: input identifiers that resolved to no CID. Omitted when every identifier resolved and for non-identifier searches.",
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

Added value: +{
+  "description": "The maxResults cap that was applied.",
+  "type": "number"
+}

Added value: +{
+  "description": "Assays returned after the maxResults cap.",
+  "type": "number"
+}

Added value: +{
+  "description": "True when results were capped at maxResults — more matching assays exist.",
+  "type": "boolean"
+}

Added value: +{
+  "description": "The maxResults cap that was applied.",
+  "type": "number"
+}

Added value: +{
+  "description": "AIDs returned after the maxResults cap.",
+  "type": "number"
+}

Added value: +{
+  "description": "True when AIDs were capped at maxResults — more assays exist than returned.",
+  "type": "boolean"
+}

Added value: +{
+  "description": "The maxResults cap that was applied.",
+  "type": "number"
+}

Added value: +{
+  "description": "CIDs returned after the maxResults cap.",
+  "type": "number"
+}

Added value: +{
+  "description": "True when CIDs were capped at maxResults — more matches exist than returned.",
+  "type": "boolean"
+}

Added value: +{
+  "description": "Filter to assays against this target protein accession (UniProt/GenBank), e.g. \"P35354\". Obtain accessions from pubchem_search_assays or the targetAccession field of an unfiltered result here.",
+  "type": "string"
+}

Added value: +{
+  "description": "Filter to assays against this NCBI Gene ID. Obtain Gene IDs from pubchem_search_assays or the targetGeneId field of an unfiltered result here. Combine with outcomeFilter=\"active\" to answer \"is this compound active against target T?\".",
+  "exclusiveMinimum": 0,
+  "maximum": 9007199254740991,
+  "type": "integer"
+}

Added value: +{
+  "description": "Assays matching the outcome and target filters, before the maxResults cap.",
+  "type": "number"
+}

Added value: +{
+  "description": "Recovery guidance when the filter yields no results or the compound has no bioactivity data.",
+  "type": "string"
+}

Added value: +{
+  "description": "Outcome filter applied: active, inactive, or all.",
+  "type": "string"
+}

Added value: +{
+  "description": "Assays returned after the maxResults cap.",
+  "type": "number"
+}

Added value: +{
+  "description": "Target filter applied (gene ID and/or protein accession), when set.",
+  "type": "string"
+}

Previous value: -[
-  "cid",
-  "totalAssays",
-  "activeCount",
-  "inactiveCount",
-  "results"
-]New value: +[
+  "cid",
+  "totalAssays",
+  "activeCount",
+  "inactiveCount",
+  "results",
+  "outcomeFilter",
+  "filteredCount",
+  "returnedCount"
+]

Removed value: -{
-  "description": "PubChem Compound ID. Resolve from name/SMILES with pubchem_search_compounds.",
-  "exclusiveMinimum": 0,
-  "maximum": 9007199254740991,
-  "type": "integer"
-}

Added value: +{
+  "description": "PubChem Compound IDs to fetch safety data for (1-25). Resolve from names/SMILES with pubchem_search_compounds.",
+  "items": {
+    "exclusiveMinimum": 0,
+    "maximum": 9007199254740991,
+    "type": "integer"
+  },
+  "maxItems": 25,
+  "minItems": 1,
+  "type": "array"
+}

Previous value: -[
-  "cid"
-]New value: +[
+  "cids"
+]

Removed value: -{
-  "description": "PubChem Compound ID.",
-  "type": "number"
-}

Removed value: -{
-  "additionalProperties": false,
-  "description": "GHS classification data.",
-  "properties": {
-    "hazardStatements": {
-      "description": "GHS hazard statements.",
-      "items": {
-        "additionalProperties": false,
-        "description": "GHS hazard statement entry.",
-        "properties": {
-          "code": {
-            "description": "H-code (e.g. \"H225\").",
-            "type": "string"
-          },
-          "statement": {
-            "description": "Hazard statement text.",
-            "type": "string"
-          }
-        },
-        "required": [
-          "code",
-          "statement"
-        ],
-        "type": "object"
-      },
-      "type": "array"
-    },
-    "pictograms": {
-      "description": "GHS pictogram labels (e.g. \"Flammable\", \"Toxic\").",
-      "items": {
-        "type": "string"
-      },
-      "type": "array"
-    },
-    "precautionaryStatements": {
-      "description": "GHS precautionary statements.",
-      "items": {
-        "additionalProperties": false,
-        "description": "GHS precautionary statement entry.",
-        "properties": {
-          "code": {
-            "description": "P-code (e.g. \"P210\").",
-            "type": "string"
-          },
-          "statement": {
-            "description": "Precautionary statement text.",
-            "type": "string"
-          }
-        },
-        "required": [
-          "code",
-          "statement"
-        ],
-        "type": "object"
-      },
-      "type": "array"
-    },
-    "signalWord": {
-      "description": "GHS signal word: \"Danger\" or \"Warning\".",
-      "type": "string"
-    }
-  },
-  "required": [
-    "pictograms",
-    "hazardStatements",
-    "precautionaryStatements"
-  ],
-  "type": "object"
-}

Removed value: -{
-  "description": "Whether GHS safety data is available for this compound.",
-  "type": "boolean"
-}

Added value: +{
+  "description": "Cross-tool guidance when one or more CIDs have no GHS data, pointing to an alternative source.",
+  "type": "string"
+}

Added value: +{
+  "description": "CIDs requested.",
+  "type": "number"
+}

Added value: +{
+  "description": "Safety results, one per requested CID (input order preserved).",
+  "items": {
+    "additionalProperties": false,
+    "description": "Per-CID safety result.",
+    "properties": {
+      "cid": {
+        "description": "PubChem Compound ID.",
+        "type": "number"
+      },
+      "ghs": {
+        "additionalProperties": false,
+        "description": "GHS classification data.",
+        "properties": {
+          "hazardStatements": {
+            "description": "GHS hazard statements.",
+            "items": {
+              "additionalProperties": false,
+              "description": "GHS hazard statement entry.",
+              "properties": {
+                "code": {
+                  "description": "H-code (e.g. \"H225\").",
+                  "type": "string"
+                },
+                "statement": {
+                  "description": "Hazard statement text.",
+                  "type": "string"
+                }
+              },
+              "required": [
+                "code",
+                "statement"
+              ],
+              "type": "object"
+            },
+            "type": "array"
+          },
+          "pictograms": {
+            "description": "GHS pictogram labels (e.g. \"Flammable\", \"Toxic\").",
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
+          "precautionaryStatements": {
+            "description": "GHS precautionary statements.",
+            "items": {
+              "additionalProperties": false,
+              "description": "GHS precautionary statement entry.",
+              "properties": {
+                "code": {
+                  "description": "P-code (e.g. \"P210\").",
+                  "type": "string"
+                },
+                "statement": {
+                  "description": "Precautionary statement text.",
+                  "type": "string"
+                }
+              },
+              "required": [
+                "code",
+                "statement"
+              ],
+              "type": "object"
+            },
+            "type": "array"
+          },
+          "signalWord": {
+            "description": "GHS signal word: \"Danger\" or \"Warning\".",
+            "type": "string"
+          }
+        },
+        "required": [
+          "pictograms",
+          "hazardStatements",
+          "precautionaryStatements"
+        ],
+        "type": "object"
+      },
+      "hasData": {
+        "description": "Whether GHS safety data is available for this compound.",
+        "type": "boolean"
+      },
+      "source": {
+        "description": "Data source attribution.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "cid",
+      "hasData"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Removed value: -{
-  "description": "Data source attribution.",
-  "type": "string"
-}

Added value: +{
+  "description": "CIDs with GHS safety data available.",
+  "type": "number"
+}

Previous value: -[
-  "cid",
-  "hasData"
-]New value: +[
+  "results",
+  "requestedCount",
+  "withDataCount"
+]

Added value: +{
+  "description": "Identifiers resolved to a summary.",
+  "type": "number"
+}

Added value: +{
+  "description": "Recovery guidance when one or more identifiers were not found.",
+  "type": "string"
+}

Added value: +{
+  "description": "Identifiers requested.",
+  "type": "number"
+}

Previous value: -[
-  "entityType",
-  "summaries"
-]New value: +[
+  "entityType",
+  "summaries",
+  "requestedCount",
+  "foundCount"
+]

Previous value: -"PubChem Compound ID."New value: +"PubChem Compound ID. Resolve from name/SMILES with pubchem_search_compounds."

Added value: +"Assay result entry."

Added value: +"Quantitative activity measurement entry."

Previous value: -"Measurement name (e.g. IC50, EC50, Ki)."New value: +"Measurement name (e.g. IC50, EC50, Ki). Omitted when not reported."

Previous value: -"Unit of measurement (e.g. uM, nM)."New value: +"Unit of measurement (e.g. uM, nM). Omitted when not reported."

Previous value: -[
-  "name",
-  "value",
-  "unit"
-]New value: +[
+  "value"
+]

Previous value: -"PubChem Compound IDs to fetch (1-100). Batched efficiently."New value: +"PubChem Compound IDs to fetch (1-100). Batched efficiently. Resolve from names/SMILES with pubchem_search_compounds."

Previous value: -"Fetch pharmacological classification from PUG View: FDA Established Pharmacologic Classes, mechanisms of action, MeSH classes, and ATC codes. Adds one API call per CID — consider limiting CID count when enabled."New value: +"Include pharmacological classification: FDA Established Pharmacologic Classes, mechanisms of action, MeSH classes, and ATC codes. Fetched only for the first 10 CIDs in the batch; remaining CIDs return without classification."

Previous value: -"Fetch textual description from PUG View (pharmacology, mechanism, therapeutic use). Adds one API call per CID — consider limiting CID count when enabled."New value: +"Include textual descriptions (pharmacology, mechanism, therapeutic use) attributed by source. Well-studied compounds have many overlapping summaries — capped via maxDescriptions. Fetched only for the first 10 CIDs in the batch; remaining CIDs return without descriptions."

Previous value: -"Fetch all known names and synonyms (trade names, systematic names, registry numbers)."New value: +"Fetch all known names and synonyms (trade names, systematic names, registry numbers). One API call per CID — slower than the property batch for large CID lists."

Added value: +{
+  "default": 3,
+  "description": "Max number of distinct description entries per compound (1-20). PubChem returns near-duplicate summaries from many depositors; we dedup and cap to keep responses focused. Default: 3.",
+  "maximum": 20,
+  "minimum": 1,
+  "type": "integer"
+}

Added value: +"Per-CID compound detail record."

Added value: +"ATC code entry with hierarchical description."

Removed value: -{
-  "description": "Textual description from PUG View.",
-  "type": "string"
-}

Added value: +{
+  "description": "Textual descriptions, deduplicated and capped at maxDescriptions. Each entry carries optional source attribution.",
+  "items": {
+    "additionalProperties": false,
+    "description": "Description entry with optional source attribution.",
+    "properties": {
+      "source": {
+        "description": "Depositor source (e.g. \"DrugBank\", \"Wikipedia\", \"ChEBI\").",
+        "type": "string"
+      },
+      "text": {
+        "description": "Description text.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "text"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Added value: +{
+  "description": "Total distinct descriptions available before truncation. Larger than descriptions.length when more sources exist — increase maxDescriptions to see them.",
+  "type": "number"
+}

Previous value: -"Molecular weight rule (≤500)."New value: +"Molecular weight rule (≤500 g/mol)."

Previous value: -"XLogP rule (≤5)."New value: +"XLogP rule (≤5; calculated logP)."

Added value: +[
+  {
+    "type": "boolean"
+  },
+  {
+    "type": "null"
+  }
+]

Previous value: -"Overall drug-likeness pass."New value: +"Overall drug-likeness pass. Null when insufficient properties were available."

Removed value: -"boolean"

Previous value: -"TPSA rule (≤140)."New value: +"Topological polar surface area rule (≤140 Ų)."

Added value: +{
+  "description": "False when the CID does not exist in PubChem (properties, description, etc. are empty).",
+  "type": "boolean"
+}

Previous value: -"Requested physicochemical properties."New value: +"Physicochemical properties keyed by name (echoes input.properties or the default core set; drug-likeness inputs are appended automatically when includeDrugLikeness is true)."

Previous value: -[
-  "cid",
-  "properties"
-]New value: +[
+  "cid",
+  "found",
+  "properties"
+]

Previous value: -"PubChem Compound ID."New value: +"PubChem Compound ID. Resolve from name/SMILES with pubchem_search_compounds."

Previous value: -"Image MIME type."New value: +"MIME type — always \"image/png\"."

Previous value: -"PubChem Compound ID."New value: +"PubChem Compound ID. Resolve from name/SMILES with pubchem_search_compounds."

Added value: +"GHS hazard statement entry."

Added value: +"GHS precautionary statement entry."

Previous value: -"PubChem Compound ID."New value: +"PubChem Compound ID. Resolve from name/SMILES with pubchem_search_compounds."

Previous value: -"Max IDs to return per xref type (1-500). A compound may have thousands of PubMed references — this cap prevents bloat. Total count always reported. Default: 50."New value: +"Max IDs to return per xref type (1-500). A compound may have thousands of PubMed references. Total count always reported. Default: 50."

Previous value: -"Cross-reference types to retrieve. Options: RegistryID, RN (CAS numbers), PubMedID, PatentID, GeneID, ProteinGI, TaxonomyID."New value: +"Cross-reference types to retrieve. String IDs: RegistryID (DSSTox/EPA registry numbers), RN (CAS numbers), PatentID. Numeric IDs: PubMedID, GeneID (NCBI Gene), ProteinGI (legacy NCBI Protein GI), TaxonomyID."

Added value: +"Cross-reference group for one type."

Previous value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "number"
-  }
-]New value: +[
+  {
+    "description": "String-form cross-reference ID (e.g. CAS number, patent).",
+    "type": "string"
+  },
+  {
+    "description": "Numeric cross-reference ID (e.g. PubMed ID, Gene ID).",
+    "type": "number"
+  }
+]

Added value: +"Cross-reference identifier — string or number depending on type."

Previous value: -"Cross-reference type."New value: +"Cross-reference type: RegistryID, RN, PubMedID, PatentID, GeneID, ProteinGI, or TaxonomyID."

Previous value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "number"
-  }
-]New value: +[
+  {
+    "description": "String identifier (e.g. UniProt accession).",
+    "type": "string"
+  },
+  {
+    "description": "Numeric identifier (e.g. AID, Gene ID, Tax ID).",
+    "type": "number"
+  }
+]

Added value: +"Entity identifier — string or number depending on entityType."

Added value: +"Per-identifier summary result."

Previous value: -{}New value: +false

Previous value: -"Entity summary data (shape varies by type)."New value: +"Entity summary data. Populated fields depend on entityType."

Added value: +{
+  "aid": {
+    "description": "Assay ID — present on assay summaries.",
+    "type": "number"
+  },
+  "commonName": {
+    "description": "Common name (taxonomy summaries).",
+    "type": "string"
+  },
+  "description": {
+    "description": "Descriptive text when available.",
+    "type": "string"
+  },
+  "geneId": {
+    "description": "NCBI Gene ID (gene summaries).",
+    "type": "number"
+  },
+  "lineage": {
+    "description": "Parent taxonomy lineage (taxonomy summaries).",
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  },
+  "name": {
+    "description": "Primary display name.",
+    "type": "string"
+  },
+  "numActive": {
+    "description": "Substances marked active (assay summaries).",
+    "type": "number"
+  },
+  "numSubstances": {
+    "description": "Substances tested (assay summaries).",
+    "type": "number"
+  },
+  "proteinAccession": {
+    "description": "Protein accession (protein summaries).",
+    "type": "string"
+  },
+  "rank": {
+    "description": "Taxonomic rank (taxonomy summaries).",
+    "type": "string"
+  },
+  "scientificName": {
+    "description": "Scientific name (taxonomy summaries).",
+    "type": "string"
+  },
+  "sourceName": {
+    "description": "Data source attribution (assay summaries).",
+    "type": "string"
+  },
+  "symbol": {
+    "description": "Gene symbol (gene summaries).",
+    "type": "string"
+  },
+  "synonyms": {
+    "description": "Known synonyms / other names.",
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  },
+  "taxonomy": {
+    "description": "Taxonomy scientific name (gene/protein summaries).",
+    "type": "string"
+  },
+  "taxonomyId": {
+    "description": "NCBI Taxonomy ID (gene/protein/taxonomy summaries).",
+    "type": "number"
+  }
+}

Removed value: -{
-  "type": "string"
-}

Previous value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "number"
-  }
-]New value: +[
+  {
+    "description": "String identifier (e.g. UniProt accession).",
+    "type": "string"
+  },
+  {
+    "description": "Numeric identifier (e.g. AID, Gene ID, Tax ID).",
+    "type": "number"
+  }
+]

Added value: +{
+  "description": "Recovery guidance when no assays matched — echoes the target and suggests alternative search types. Absent when assays were returned.",
+  "type": "string"
+}

Previous value: -"Target identifier type used."New value: +"Target identifier type used: genesymbol, proteinname, geneid, or proteinaccession."

Previous value: -"Total AIDs found."New value: +"Total AIDs found before the maxResults cap."

Previous value: -[
-  "targetType",
-  "targetQuery",
-  "totalFound",
-  "aids"
-]New value: +[
+  "aids",
+  "targetType",
+  "targetQuery",
+  "totalFound"
+]

Previous value: -"Required for identifier search. Array of identifiers to resolve (1-25). Examples: [\"aspirin\", \"ibuprofen\"] for name, [\"CC(=O)OC1=CC=CC=C1C(=O)O\"] for SMILES."New value: +"Required for identifier search. Array of identifiers to resolve (1-25). Examples: [\"aspirin\", \"ibuprofen\"] for name, [\"CC(=O)OC1=CC=CC=C1C(=O)O\"] for SMILES, [\"BSYNRYMUTXBXSQ-UHFFFAOYSA-N\"] for inchikey (27-char block format)."

Previous value: -"Required for substructure/superstructure/similarity searches. A SMILES string or PubChem CID (as string) for the query structure."New value: +"Required for substructure/superstructure/similarity searches. A SMILES string (e.g. \"CC(=O)O\") or PubChem CID as a string (e.g. \"2244\")."

Previous value: -"Search strategy: \"identifier\" (name/SMILES/InChIKey lookup), \"formula\", \"substructure\", \"superstructure\", or \"similarity\"."New value: +"Search strategy. \"identifier\": name/SMILES/InChIKey lookup. \"formula\": molecular formula. \"substructure\": find compounds containing the query as a substructure. \"superstructure\": find compounds that are themselves substructures of the query. \"similarity\": 2D Tanimoto similarity to the query."

Added value: +{
+  "description": "Recovery guidance when no compounds matched — echoes search strategy and suggests how to broaden. Absent when results were returned.",
+  "type": "string"
+}

Added value: +"Matching compound entry."

Previous value: -"Compound properties when requested."New value: +"Compound properties keyed by name (echoes input.properties; only present when requested)."

Previous value: -"The search strategy used."New value: +"Search strategy used: identifier, formula, substructure, superstructure, or similarity."

Previous value: -"Total CIDs found (before maxResults cap)."New value: +"Total CIDs found before the maxResults cap."

Previous value: -[
-  "searchType",
-  "totalFound",
-  "results"
-]New value: +[
+  "results",
+  "searchType",
+  "totalFound"
+]