Tools

MCP tool: resolve_datachain

Compose a thin DatachainInstance plus the pinned schema slice into a ResolvedDatachainInstance.

`resolve_datachain`

Soft-failure (isError: false) on parse and semantic-validate errors. The 512 KB cap returns a payload_too_large error envelope.

Summary

MCP sibling to POST /schemas/:version/resolve. Composes a thin DatachainInstance and the pinned schema's lean subset (datachain_type + referenced categories + referenced elements) into a single self-contained ResolvedDatachainInstance.

Input

{
  "version": "dtpr@2026-09-01-beta",
  "datachain": { /* DatachainInstance — `id`, `schema_version`, `created_at`, and a non-empty `elements[]` are required */ }
}

Output — success

{
  "structuredContent": {
    "ok": true,
    "data": {
      "id": "acme-resume-screener",
      "schema_version": "dtpr@2026-09-01-beta",
      "created_at": "2026-09-01T00:00:00Z",
      "elements": [ "/* the placements from the request, unchanged */" ],
      "schema_snapshot": { "datachain_type": {...}, "categories": [...], "elements": [...] },
      "suggested_elements": []
    },
    "meta": { "content_hash": "sha256-…", "version": "dtpr@2026-09-01-beta" }
  },
  "content": [{ "type": "text", "text": "{...}" }]
}

Output — semantic failure

{
  "structuredContent": {
    "ok": false,
    "errors": [{ "code": "INSTANCE_ELEMENT_UNKNOWN", "message": "…", "path": "elements[0]" }]
  }
}

Output — payload too large

When the resolved bundle exceeds 512 KB, the soft-failure envelope carries a typed payload_too_large error (no HTTP semantics in MCP):

{
  "structuredContent": {
    "ok": false,
    "errors": [
      {
        "code": "payload_too_large",
        "message": "Resolved bundle exceeds 524288-byte cap (got 612904).",
        "fix_hint": "Reduce locales/elements/categories pinned by the schema, or fetch the schema content separately."
      }
    ]
  }
}

Example

curl -s https://api.dtpr.io/mcp \
  -H 'content-type: application/json' \
  -H 'accept: application/json, text/event-stream' \
  --data '{
    "jsonrpc":"2.0","id":1,
    "method":"tools/call",
    "params":{
      "name":"resolve_datachain",
      "arguments":{
        "version":"dtpr@2026-09-01-beta",
        "datachain":{
          "id":"acme-resume-screener",
          "schema_version":"dtpr@2026-09-01-beta",
          "created_at":"2026-09-01T00:00:00Z",
          "elements":[
            {"element_id":"employment"},
            {"element_id":"organization","context_type_id":"deployer","variables":[
              {"id":"title","value":[{"locale":"en","value":"Acme Corp"}]},
              {"id":"description","value":[{"locale":"en","value":"Runs the screener."}]}]},
            {"element_id":"people","context_type_id":"subject","variables":[
              {"id":"title","value":[{"locale":"en","value":"Job applicants"}]},
              {"id":"description","value":[{"locale":"en","value":"Anyone who submits a resume."}]}]},
            {"element_id":"recommends","context_type_id":"human_decides"}
          ]
        }
      }
    }
  }'