Previous value: -"The target concept's RxNorm type, present on `rxcui_to_ingredients`, `rxcui_to_brands`, and `class_to_rxcuis` hits only. A class member may be any drug concept: an ingredient type below, or a drug product — \"SCD\"/\"SBD\" (clinical/branded drug) or \"GPCK\"/\"BPCK\" (generic/branded pack). Otherwise \"IN\" (ingredient), \"PIN\" (precise ingredient — a specific salt, ester, or isomer of an ingredient), \"MIN\" (multiple ingredients — a concept naming a combination, never a substance within it), or \"BN\" (brand name). Ingredient hits mix the first three, so the hit count is not the substance count: a \"MIN\" hit is the grouping concept and never counts, and a \"PIN\" names a form of a substance rather than an extra one — usually alongside the \"IN\" it refines, though two \"PIN\" esters can share a single \"IN\". Counting the \"IN\" hits is the closest reading, and under-counts those shared cases."New value: +"The target concept's RxNorm type, present on `name_to_rxcui`, `ndc_to_rxcui`, `rxcui_to_ingredients`, `rxcui_to_brands`, and `class_to_rxcuis` hits only. A drug-name match or a class member may be any drug concept: an ingredient type or brand name below, or a drug product — \"SCD\"/\"SBD\" (clinical/branded drug) or \"GPCK\"/\"BPCK\" (generic/branded pack), the four an `ndc_to_rxcui` hit always takes. Otherwise \"IN\" (ingredient), \"PIN\" (precise ingredient — a specific salt, ester, or isomer of an ingredient), \"MIN\" (multiple ingredients — a concept naming a combination, never a substance within it), or \"BN\" (brand name). Ingredient hits mix the first three, so the hit count is not the substance count: a \"MIN\" hit is the grouping concept and never counts, and a \"PIN\" names a form of a substance rather than an extra one — usually alongside the \"IN\" it refines, though two \"PIN\" esters can share a single \"IN\". Counting the \"IN\" hits is the closest reading, and under-counts those shared cases."

Previous value: -"Guidance whenever a resolvable source returns no hits, naming which of the two causes applies: it has no edge in the requested direction (a top-level code has no parent; a leaf has no children; ICD-10-PCS codes have no prefix parent; RxNorm concepts have no code hierarchy; no bundled class, or none of the requested `classType`, covers the RXCUI; a class has no direct member), or the `cursor` starts past the last page of a direction that does have results."New value: +"Guidance whenever a resolvable source returns no hits, naming which of the two causes applies: it has no edge in the requested direction (a top-level code has no parent; a leaf has no children; an ICD-10-PCS table row has no parent; RxNorm concepts have no code hierarchy; no bundled class, or none of the requested `classType`, covers the RXCUI; a class has no direct member), or the `cursor` starts past the last page of a direction that does have results."

Previous value: -"Machine-readable failure mode. Declared by this tool: `field_not_applicable`: A `system`, `classType`, `limit`, or `cursor` was sent on a direction that does not use it. `no_mapping`: The source value did not resolve to any bundled code, drug, or class. `direction_unavailable`: A drug-crosswalk direction was requested but this build carries no RxNorm tables, or a class direction was requested but it carries no RxClass class layer. `ambiguous_system`: The source code is present in more than one system and no `system` was given. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `field_not_applicable`: A `system`, `classType`, `limit`, or `cursor` was sent on a direction that does not use it. `no_mapping`: The source value did not resolve to a bundled code, drug, or class the direction reads. The rxcui_to_* directions read RxNorm concepts only, and their miss names any other bundled system that holds the value. `direction_unavailable`: A drug-crosswalk direction was requested but this build carries no RxNorm tables, or a class direction was requested but it carries no RxClass class layer. `ambiguous_system`: The source code is present in more than one system and no `system` was given. Other values are possible when a failure originates below the handler."

Added value: +{
+  "description": "For rxcui_to_classes and class_to_rxcuis only: keep only classes of this RxClass type — EPC (FDA established pharmacologic class), MOA (mechanism of action), PE (physiologic effect), PK (pharmacokinetics), TC (therapeutic category), CHEM (chemical structure), DISEASE (diseases the drug may treat, prevent, diagnose, or induce, or is contraindicated with), VA (VA drug class, recorded almost only on drug products), SCHEDULE (DEA controlled-substance schedule, recorded on drug products only), CVX (CDC vaccine code). Omit for every type. Rejected on every other direction.",
+  "enum": [
+    "EPC",
+    "MOA",
+    "PE",
+    "PK",
+    "TC",
+    "CHEM",
+    "DISEASE",
+    "VA",
+    "SCHEDULE",
+    "CVX"
+  ],
+  "type": "string"
+}

Previous value: -"Opaque continuation token from a previous response's `nextCursor`, for the paginated directions only (children, name_to_rxcui, rxcui_to_ndc). Omit for the first page; an empty string counts as omitted. A non-empty cursor on any other direction is rejected."New value: +"Opaque continuation token from a previous response's `nextCursor`, for the paginated directions only (children, name_to_rxcui, rxcui_to_ndc, rxcui_to_classes, class_to_rxcuis). Omit for the first page; an empty string counts as omitted. A non-empty cursor on any other direction is rejected."

Previous value: -"What to map to. parents/children return the immediate parent or children only (depth-1) — call iteratively to walk a full path; the rxcui/ndc/name directions are RxNorm drug crosswalks."New value: +"What to map to. parents/children return the immediate parent or children only (depth-1) — call iteratively to walk a full path; the rxcui/ndc/name directions are RxNorm drug crosswalks; rxcui_to_classes and class_to_rxcuis are RxClass drug-class crosswalks."

Previous value: -[
-  "parents",
-  "children",
-  "name_to_rxcui",
-  "ndc_to_rxcui",
-  "rxcui_to_ndc",
-  "rxcui_to_ingredients",
-  "rxcui_to_brands"
-]New value: +[
+  "parents",
+  "children",
+  "name_to_rxcui",
+  "ndc_to_rxcui",
+  "rxcui_to_ndc",
+  "rxcui_to_ingredients",
+  "rxcui_to_brands",
+  "rxcui_to_classes",
+  "class_to_rxcuis"
+]

Previous value: -"The source value: a code (for parents/children), a drug name, an NDC, or an RXCUI. Must not be blank or whitespace-only."New value: +"The source value: a code (for parents/children), a drug name, an NDC, an RXCUI, or an RxClass class ID (for class_to_rxcuis). Must not be blank or whitespace-only."

Previous value: -"Max results per page, for the paginated directions only (children, name_to_rxcui, rxcui_to_ndc). Defaults to MEDCODE_MAX_RESULTS (50), ceiling 200. Rejected on every other direction."New value: +"Max results per page, for the paginated directions only (children, name_to_rxcui, rxcui_to_ndc, rxcui_to_classes, class_to_rxcuis). Defaults to MEDCODE_MAX_RESULTS (50), ceiling 200. Rejected on every other direction."

Previous value: -"For parents/children, force the source code into this system. Omit to auto-detect. The drug directions resolve in RxNorm and accept only \"RXNORM\" (no effect); any other value there is rejected."New value: +"For parents/children, force the source code into this system. Omit to auto-detect. The drug and class directions resolve in RxNorm and accept only \"RXNORM\" (no effect); any other value there is rejected."

Previous value: -"Machine-readable failure mode. Declared by this tool: `field_not_applicable`: A `system`, `limit`, or `cursor` was sent on a direction that does not use it. `no_mapping`: The source value did not resolve to any bundled code. `direction_unavailable`: A drug-crosswalk direction was requested but this build carries no RxNorm tables. `ambiguous_system`: The source code is present in more than one system and no `system` was given. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `field_not_applicable`: A `system`, `classType`, `limit`, or `cursor` was sent on a direction that does not use it. `no_mapping`: The source value did not resolve to any bundled code, drug, or class. `direction_unavailable`: A drug-crosswalk direction was requested but this build carries no RxNorm tables, or a class direction was requested but it carries no RxClass class layer. `ambiguous_system`: The source code is present in more than one system and no `system` was given. Other values are possible when a failure originates below the handler."

Added value: +{
+  "description": "The RxClass class type, on `rxcui_to_classes` and `class_to_rxcuis` hits only — the values the `classType` input takes.",
+  "enum": [
+    "EPC",
+    "MOA",
+    "PE",
+    "PK",
+    "TC",
+    "CHEM",
+    "DISEASE",
+    "VA",
+    "SCHEDULE",
+    "CVX"
+  ],
+  "type": "string"
+}

Previous value: -"The target concept's RxNorm type, present on `rxcui_to_ingredients` and `rxcui_to_brands` hits only: \"IN\" (ingredient), \"PIN\" (precise ingredient — a specific salt, ester, or isomer of an ingredient), \"MIN\" (multiple ingredients — a concept naming a combination, never a substance within it), or \"BN\" (brand name). Ingredient hits mix the first three, so the hit count is not the substance count: a \"MIN\" hit is the grouping concept and never counts, and a \"PIN\" names a form of a substance rather than an extra one — usually alongside the \"IN\" it refines, though two \"PIN\" esters can share a single \"IN\". Counting the \"IN\" hits is the closest reading, and under-counts those shared cases."New value: +"The target concept's RxNorm type, present on `rxcui_to_ingredients`, `rxcui_to_brands`, and `class_to_rxcuis` hits only. A class member may be any drug concept: an ingredient type below, or a drug product — \"SCD\"/\"SBD\" (clinical/branded drug) or \"GPCK\"/\"BPCK\" (generic/branded pack). Otherwise \"IN\" (ingredient), \"PIN\" (precise ingredient — a specific salt, ester, or isomer of an ingredient), \"MIN\" (multiple ingredients — a concept naming a combination, never a substance within it), or \"BN\" (brand name). Ingredient hits mix the first three, so the hit count is not the substance count: a \"MIN\" hit is the grouping concept and never counts, and a \"PIN\" names a form of a substance rather than an extra one — usually alongside the \"IN\" it refines, though two \"PIN\" esters can share a single \"IN\". Counting the \"IN\" hits is the closest reading, and under-counts those shared cases."

Previous value: -"Description of the target when available: the code description for hierarchy hits, the official RxNorm name for the `name_to_rxcui`, `ndc_to_rxcui`, `rxcui_to_ingredients`, and `rxcui_to_brands` drug concepts. Absent for `rxcui_to_ndc`, whose targets are package identifiers with no description of their own."New value: +"Description of the target when available: the code description for hierarchy hits, the official RxNorm name for the `name_to_rxcui`, `ndc_to_rxcui`, `rxcui_to_ingredients`, `rxcui_to_brands`, and `class_to_rxcuis` drug concepts, and the class name for `rxcui_to_classes`. Absent for `rxcui_to_ndc`, whose targets are package identifiers with no description of their own."

Added value: +{
+  "description": "The RxClass relationship between the drug and the class, on `rxcui_to_classes` and `class_to_rxcuis` hits only: has_epc, has_moa, has_pe, has_pk, site_of_metabolism, has_tc, has_ingredient / has_chemical_structure / has_active_metabolites (CHEM), may_treat / may_prevent / may_diagnose / induces (DISEASE), has_vaclass / has_vaclass_extended, has_schedule, isa_cvx. A `ci_` relation (ci_with, ci_moa, ci_pe, ci_chemclass) is a contraindication: the drug is contraindicated with that disease or class — never an indication, and never class membership.",
+  "type": "string"
+}

Previous value: -"Which system or relationship edge produced this hit (e.g. \"ICD10CM\", \"has_ingredient\", \"NDC\")."New value: +"Which system or relationship edge produced this hit (e.g. \"ICD10CM\", \"has_ingredient\", \"NDC\"). On the class directions, the RxClass source asserting the drug–class edge: \"MEDRT\" (VA MED-RT), \"FDASPL\" (FDA structured product labels), \"FMTSME\" (Federal Medication Terminologies), \"VA\" (VA National Formulary classes), \"RXNORM\" (DEA schedules as RxNorm records them), or \"CDC\" (CVX vaccine codes)."

Previous value: -"The code system of the target value, or null when the target is not a system code (e.g. an NDC)."New value: +"The code system of the target value, or null when the target is not a system code (an NDC, or an RxClass class ID)."

Previous value: -"The mapped target value (a code, RXCUI, or NDC)."New value: +"The mapped target value (a code, RXCUI, NDC, or RxClass class ID)."

Added value: +{
+  "description": "On `rxcui_to_classes` hits only: the ingredient RXCUI a drug product inherits this class through — RxClass attaches most classes to ingredients. Absent when the class attaches to the source RXCUI itself. When several ingredients carry the same class, names an ingredient (\"IN\") over its precise ingredient (\"PIN\"), then the lowest RXCUI.",
+  "type": "string"
+}

Previous value: -"Guidance whenever a resolvable source returns no hits, naming which of the two causes applies: it has no edge in the requested direction (a top-level code has no parent; a leaf has no children; ICD-10-PCS codes have no prefix parent; RxNorm concepts have no code hierarchy), or the `cursor` starts past the last page of a direction that does have results."New value: +"Guidance whenever a resolvable source returns no hits, naming which of the two causes applies: it has no edge in the requested direction (a top-level code has no parent; a leaf has no children; ICD-10-PCS codes have no prefix parent; RxNorm concepts have no code hierarchy; no bundled class, or none of the requested `classType`, covers the RXCUI; a class has no direct member), or the `cursor` starts past the last page of a direction that does have results."

Previous value: -"Paginated directions (children, name_to_rxcui, rxcui_to_ndc) only: true when more results exist beyond this page."New value: +"Paginated directions (children, name_to_rxcui, rxcui_to_ndc, rxcui_to_classes, class_to_rxcuis) only: true when more results exist beyond this page."

Previous value: -"Opaque continuation token from a previous response's `nextCursor`, for the paginated directions (children, name_to_rxcui, rxcui_to_ndc). Omit for the first page."New value: +"Opaque continuation token from a previous response's `nextCursor`, for the paginated directions only (children, name_to_rxcui, rxcui_to_ndc). Omit for the first page; an empty string counts as omitted. A non-empty cursor on any other direction is rejected."

Previous value: -"Max results per page for the paginated directions (children, name_to_rxcui, rxcui_to_ndc). Defaults to MEDCODE_MAX_RESULTS (50), ceiling 200. Ignored by the point directions."New value: +"Max results per page, for the paginated directions only (children, name_to_rxcui, rxcui_to_ndc). Defaults to MEDCODE_MAX_RESULTS (50), ceiling 200. Rejected on every other direction."

Previous value: -"For parents/children, force the source code into this system. Omit to auto-detect."New value: +"For parents/children, force the source code into this system. Omit to auto-detect. The drug directions resolve in RxNorm and accept only \"RXNORM\" (no effect); any other value there is rejected."

Previous value: -"Machine-readable failure mode. Declared by this tool: `no_mapping`: The source value did not resolve to any bundled code. `direction_unavailable`: A drug-crosswalk direction was requested but this build carries no RxNorm tables. `ambiguous_system`: The source code is present in more than one system and no `system` was given. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `field_not_applicable`: A `system`, `limit`, or `cursor` was sent on a direction that does not use it. `no_mapping`: The source value did not resolve to any bundled code. `direction_unavailable`: A drug-crosswalk direction was requested but this build carries no RxNorm tables. `ambiguous_system`: The source code is present in more than one system and no `system` was given. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "no_mapping",
-  "direction_unavailable",
-  "ambiguous_system"
-]New value: +[
+  "field_not_applicable",
+  "no_mapping",
+  "direction_unavailable",
+  "ambiguous_system"
+]

Previous value: -"Guidance whenever a resolvable source returns no hits, naming which of the two causes applies: it has no edge in the requested direction (a top-level code has no parent; a leaf has no children; ICD-10-PCS codes have no prefix parent), or the `cursor` starts past the last page of a direction that does have results."New value: +"Guidance whenever a resolvable source returns no hits, naming which of the two causes applies: it has no edge in the requested direction (a top-level code has no parent; a leaf has no children; ICD-10-PCS codes have no prefix parent; RxNorm concepts have no code hierarchy), or the `cursor` starts past the last page of a direction that does have results."

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

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

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

Added value: +[
+  "string",
+  "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": [
+      "from",
+      "direction",
+      "resolvedSystem",
+      "hits"
+    ]
+  },
+  {
+    "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_mapping`: The source value did not resolve to any bundled code. `direction_unavailable`: A drug-crosswalk direction was requested but this build carries no RxNorm tables. `ambiguous_system`: The source code is present in more than one system and no `system` was given. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "no_mapping",
+            "direction_unavailable",
+            "ambiguous_system"
+          ],
+          "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: -[
-  "from",
-  "direction",
-  "resolvedSystem",
-  "hits"
-]

Previous value: -"Opaque continuation token from a previous response's `nextCursor`, for the paginated directions (children, name_to_rxcui). Omit for the first page."New value: +"Opaque continuation token from a previous response's `nextCursor`, for the paginated directions (children, name_to_rxcui, rxcui_to_ndc). Omit for the first page."

Previous value: -"Max results per page for the paginated directions (children, name_to_rxcui). Defaults to MEDCODE_MAX_RESULTS (50), ceiling 200. Ignored by the point directions."New value: +"Max results per page for the paginated directions (children, name_to_rxcui, rxcui_to_ndc). Defaults to MEDCODE_MAX_RESULTS (50), ceiling 200. Ignored by the point directions."

Added value: +{
+  "description": "Other bundled systems holding the same `from` code string, present only when there is at least one (hierarchy directions only — a drug name, NDC, or RXCUI is not system-scoped). The hits above were walked in `resolvedSystem` alone; the code is a DIFFERENT code with a different hierarchy in each system listed here — \"B00\" is the ICD-10-CM category \"Herpesviral [herpes simplex] infections\" and also the ICD-10-PCS table row \"Imaging, Central Nervous System, Plain Radiography\". Re-call with `system` set to one of these values to walk it there.",
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

Added value: +{
+  "description": "The target concept's RxNorm type, present on `rxcui_to_ingredients` and `rxcui_to_brands` hits only: \"IN\" (ingredient), \"PIN\" (precise ingredient — a specific salt, ester, or isomer of an ingredient), \"MIN\" (multiple ingredients — a concept naming a combination, never a substance within it), or \"BN\" (brand name). Ingredient hits mix the first three, so the hit count is not the substance count: a \"MIN\" hit is the grouping concept and never counts, and a \"PIN\" names a form of a substance rather than an extra one — usually alongside the \"IN\" it refines, though two \"PIN\" esters can share a single \"IN\". Counting the \"IN\" hits is the closest reading, and under-counts those shared cases.",
+  "type": "string"
+}

Previous value: -"Description of the target when available."New value: +"Description of the target when available: the code description for hierarchy hits, the official RxNorm name for the `name_to_rxcui`, `ndc_to_rxcui`, `rxcui_to_ingredients`, and `rxcui_to_brands` drug concepts. Absent for `rxcui_to_ndc`, whose targets are package identifiers with no description of their own."

Previous value: -"Guidance when a resolvable code has no edge in the requested direction (e.g. a top-level code has no parent; a leaf has no children; ICD-10-PCS codes have no prefix parent)."New value: +"Guidance whenever a resolvable source returns no hits, naming which of the two causes applies: it has no edge in the requested direction (a top-level code has no parent; a leaf has no children; ICD-10-PCS codes have no prefix parent), or the `cursor` starts past the last page of a direction that does have results."

Previous value: -"Paginated directions (children, name_to_rxcui) only: true when more results exist beyond this page."New value: +"Paginated directions (children, name_to_rxcui, rxcui_to_ndc) only: true when more results exist beyond this page."

Previous value: -"The source value: a code (for parents/children), a drug name, an NDC, or an RXCUI."New value: +"The source value: a code (for parents/children), a drug name, an NDC, or an RXCUI. Must not be blank or whitespace-only."

Added value: +{
+  "description": "Opaque continuation token from a previous response's `nextCursor`, for the paginated directions (children, name_to_rxcui). Omit for the first page.",
+  "type": "string"
+}

Added value: +{
+  "description": "Max results per page for the paginated directions (children, name_to_rxcui). Defaults to MEDCODE_MAX_RESULTS (50), ceiling 200. Ignored by the point directions.",
+  "maximum": 200,
+  "minimum": 1,
+  "type": "integer"
+}

Added value: +{
+  "description": "Paginated directions only: the page size that was applied.",
+  "type": "number"
+}

Added value: +{
+  "description": "Paginated directions only: opaque token to pass back as `cursor` for the next page. Present only when more results exist beyond this page.",
+  "type": "string"
+}

Added value: +{
+  "description": "Paginated directions only: number of hits returned on this page.",
+  "type": "number"
+}

Added value: +{
+  "description": "Paginated directions (children, name_to_rxcui) only: true when more results exist beyond this page.",
+  "type": "boolean"
+}

Previous value: -"What to map to. parents/children return the immediate parent or children only (depth-1) — call iteratively to walk a full path; the rxcui/ndc/name directions are RxNorm drug crosswalks (phase 2)."New value: +"What to map to. parents/children return the immediate parent or children only (depth-1) — call iteratively to walk a full path; the rxcui/ndc/name directions are RxNorm drug crosswalks."

Previous value: -"What to map to. parents/children walk the code hierarchy; the rxcui/ndc/name directions are RxNorm drug crosswalks (phase 2)."New value: +"What to map to. parents/children return the immediate parent or children only (depth-1) — call iteratively to walk a full path; the rxcui/ndc/name directions are RxNorm drug crosswalks (phase 2)."

Added value: +{
+  "description": "Guidance when a resolvable code has no edge in the requested direction (e.g. a top-level code has no parent; a leaf has no children; ICD-10-PCS codes have no prefix parent).",
+  "type": "string"
+}