Added value: +"HOW YOU KNOW. This is the field the product is built around, so say what is true rather than what is strongest: `observed` you saw it stated directly, `imported` it came from a file or another system, `inferred` you worked it out, `user_supplied` a person told you in so many words. They rank, weakest first: inferred < imported < observed < user_supplied < confirmed. A weaker claim does not overwrite a stronger one; it is reported in `held[]` and the stored value stands, so an unattended re-run converges instead of eroding what somebody checked. `confirmed` is not accepted here: it means a person checked the value, and only a signed-in person can set it."

Added value: +"A short name for the work this write belongs to, shown beside the actor so one credential can distinguish separate jobs. It is recorded as CALLER-SUPPLIED and grants nothing: it changes no permission, no idempotency scope and no quota."

Previous value: -trueNew value: +{
+  "anyOf": [
+    {
+      "maxLength": 2000,
+      "type": "string"
+    },
+    {
+      "type": "integer"
+    },
+    {
+      "type": "boolean"
+    },
+    {
+      "type": "null"
+    }
+  ]
+}

Added value: +"Values for fields this workspace defined, keyed by the field's key. Read the schema first: a key that is not declared is REFUSED, with the available keys in the error, rather than stored where nobody will find it. Send null to clear one."

Added value: +"Report what this write WOULD do and commit nothing. The response carries the same change list, held fields and refusals as the real call, so it is the way to check a risky write, or a whole import, before it lands. Nothing is metered."

Added value: +"The version you read before deciding to write. If the record has moved since, the write is refused instead of overwriting whatever changed. Send it whenever you read, reasoned, and then wrote: without it the last writer wins and neither of you finds out."

Added value: +"Your own name for this write, so retrying it cannot do it twice. Send the same key again and you get the SAME result back rather than a second record, which is what makes a re-run safe after a timeout you never saw the answer to. Derive it from what the write is about, not from the clock: `nightly-sync-halden` retries correctly and a timestamp does not."

Added value: +"Apply this write even when the value standing in the record was asserted more strongly than this one. Absent means no, which is the safe answer for a re-run. WITHOUT IT, a write can be accepted and change nothing: precedence is confirmed > user_supplied > observed > imported > inferred, and a weaker claim leaves the standing value in place and reports the field in `held[]` rather than failing. That is the whole of why a write can return 200 and not take. WITH it, this write wins regardless of what it is overruling, INCLUDING a value a person confirmed, so an agent that sets it by default has switched the provenance mechanism off. Set it per write, when the caller knows its claim supersedes what is there."

Added value: +"The recorded source this claim came from, if one exists. It attaches evidence to the write, so a person reading the field later can see where it came from rather than only who sent it."

Added value: +"Only records in this stage. Stage ids come from the schema call, which lists every pipeline and its stages in order."

Added value: +"The records the evidence fits, when it fits more than one. Send the upsert again naming the `id` you mean."

Added value: +"Why this matched the record it matched, in words, when it matched one."

Added value: +"What the write did. Absent when nothing was written, which is the ambiguous case."

Added value: +"The record as it stands. Absent on an ambiguous upsert and on a dry run."

Added value: +"Whether this created a record, matched an existing one on real identity evidence, or found several and committed nothing. `ambiguous` is not an error: it means the evidence you sent fits more than one record, and `candidates` lists them so a caller can choose rather than have one picked for it."