What do omitted, null, [] and "" mean in this PATCH body under merge-patch, JSON Patch or a declared dialect?

$0.005 USDC per call · Agent infrastructure · POST /api/v1/update-dialect · Id update-dialect

For an agent about to send a PATCH or update body: states, per field, what omitted / null / [] / "" mean under the declared dialect (RFC 7396 merge patch, RFC 6902 JSON Patch, or caller-declared semantics) and checks the body against stated intents such as 'clear this field', 'leave this alone' or 'set to empty array'. With a target document it applies the patch and compares the result; without one it reasons about the patch alone and says when an intent cannot be verified. Does not know which dialect a given API uses: the caller declares it. Merge patch cannot store a null (null deletes); JSON Patch can.

What you get

Stops 'null means clear' being sent to an API where null deletes, or [] wiping a list the agent meant to leave alone.

Call it

Send the JSON body below to https://agents.writerslogic.com/api/v1/update-dialect. An unpaid request answers 402 with the price and how to pay; a request that fails with a 5xx status is not charged.

curl -i -X POST https://agents.writerslogic.com/api/v1/update-dialect \
  -H 'content-type: application/json' \
  -d '{"dialect":"merge-patch","payload":{"nickname":null,"tags":[]},"intents":[{"path":"/nickname","expect":"null"},{"path":"/email","expect":"unchanged"}]}'

Input

Field	Type	Required	Description
`dialect`	string; one of "merge-patch", "json-patch", "caller"	yes	merge-patch = RFC 7396, json-patch = RFC 6902 (payload is an array of operations), caller = semantics in callerSemantics.
`payload`	any	yes	The PATCH body.
`target`	any	no	Current document, if available. Enables applying the patch and exact checks.
`intents`	array<object>; max 100 items	no
`callerSemantics`	object	no	Required when dialect is 'caller': what each payload form means in that API.

Example request body

{
  "dialect": "merge-patch",
  "payload": {
    "nickname": null,
    "tags": []
  },
  "intents": [
    {
      "path": "/nickname",
      "expect": "null"
    },
    {
      "path": "/email",
      "expect": "unchanged"
    }
  ]
}

Result

The response is { "data": ..., "_provenance": ... }. data carries these fields; _provenance is a signed W3C Verifiable Credential with a C2PA-style manifest, checked free at POST /api/v1/verify-provenance.

Field	Type	Required	Description
`status`	string; one of "pass", "fail", "unknown", "unsupported"	no	pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass.
`effects`	array<object>	no	At most 500 listed, in payload order.
`effectCount`	integer	no	Total effects found, which can exceed the number listed.
`verdicts`	array<object>	no
`applied`	any	no	The document after applying the patch; present only when a target was given and the patch applied.
`witnesses`	array<object>	no
`versions`	object	no	Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile).
`limits`	array<string>	no
`deterministic`	boolean	no	Always true: pure code, no model.

Pay and connect

Available through: x402 (USDC on Base), MCP. MCP clients reach it through the execution-safety-kit package.

Machine-readable

This agent as JSON (schemas, example, OpenAPI operation)
Free signed sample response
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