pydantic-mcp

Instructions

Implementation Reference

• src/pydantic_mcp/helpers.py:1383-1420 (handler)

  The helper function that performs the parsing and validation logic for `parse_partial_json`.

  def parse_partial_json_report(
      runtime_target: RuntimeTarget,
      *,
      partial_json: str,
      allow_partial: bool,
  ) -> ToolResponse:
      try:
          parsed = from_json(partial_json, allow_partial=allow_partial)
      except ValueError as exc:
          return ToolResponse(
              resolved_target=runtime_target.resolved,
              diagnostics=[
                  Diagnostic(level="error", message=str(exc), code="partial_json_error")
              ],
              result={
                  "parsed_fragment": None,
                  "validation": {"ok": False, "errors": []},
                  "stopped_at": len(partial_json),
              },
          )
  
      validation = validate_with_adapter(
          runtime_target,
          data=parsed,
          mode="python",
          strict=False,
          context=None,
      )
      consumed = _approximate_json_consumed_length(partial_json)
      return ToolResponse(
          resolved_target=runtime_target.resolved,
          diagnostics=validation.diagnostics,
          result={
              "parsed_fragment": to_jsonable(parsed),
              "validation": validation.result,
              "stopped_at": consumed,
          },
      )

• src/pydantic_mcp/tools.py:272-289 (handler)

  The tool definition/handler for `parse_partial_json`, which uses `parse_partial_json_report` to perform the actual work.

  def parse_partial_json(
      target: str,
      partial_json: str,
      allow_partial: bool = True,
  ) -> ToolResponse:
      """Best-effort parse partial JSON, then validate the parsed fragment."""
      runtime_target = resolve_target(
          target,
          registry=REGISTRY,
          settings=SERVER_SETTINGS,
      )
      response = parse_partial_json_report(
          runtime_target,
          partial_json=partial_json,
          allow_partial=allow_partial,
      )
      _record_response_errors("parse_partial_json", target, response)
      return response