Weavers / MCP documentation

Propose a source change

Save a replacement strategy.py proposal for the owner to compare and apply.

Creates a draft or proposalpropose_python_source

Required permission: weavers.python_source.propose

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Propose a clearer strategy.py implementation and explain the changes. Leave it for me to review in Weavers.

How it works

Creates a stored proposal. The current source file stays unchanged until the owner applies it in Weavers.
Provide the complete replacement source, a reason, and the exact context revisions. Source is bounded to 512 KiB of UTF-8 text, with no null bytes or unpaired surrogates.
If no source exists, use baseSourceRevision: 0 and baseSourceSha256: null. Dataset ID/hash and draft ID/revision must each be supplied together or both null.
Use a new proposal UUID for a new proposal. Identical retries reuse the existing proposal; changed content with the same ID is rejected.
If the context changes, refresh it and prepare a new proposal. The returned URL opens the implementation review.

Inputs

Field	Required	Type & constraints
proposalId	Required	UUID string
strategyId	Required	UUID string
strategyRevision	Required	integer; greater than 0
baseSourceRevision	Required	integer; minimum 0
baseSourceSha256	Required	string; 64 lowercase hexadecimal characters or null
datasetVersionId	Required	UUID string or null
datasetSha256	Required	string; 64 lowercase hexadecimal characters or null
experimentDraftId	Required	UUID string or null
experimentDraftRevision	Required	integer; greater than 0 or null
source	Required	string; at least 1 characters; up to 524288 characters
reason	Required	string; at least 1 characters; up to 2000 characters

View complete input JSON schema

Input schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "proposalId": {
      "type": "string",
      "format": "uuid",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
    },
    "strategyId": {
      "type": "string",
      "format": "uuid",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
    },
    "strategyRevision": {
      "type": "integer",
      "exclusiveMinimum": 0,
      "maximum": 9007199254740991
    },
    "baseSourceRevision": {
      "type": "integer",
      "minimum": 0,
      "maximum": 9007199254740991
    },
    "baseSourceSha256": {
      "anyOf": [
        {
          "type": "string",
          "pattern": "^[a-f0-9]{64}$"
        },
        {
          "type": "null"
        }
      ]
    },
    "datasetVersionId": {
      "anyOf": [
        {
          "type": "string",
          "format": "uuid",
          "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
        },
        {
          "type": "null"
        }
      ]
    },
    "datasetSha256": {
      "anyOf": [
        {
          "type": "string",
          "pattern": "^[a-f0-9]{64}$"
        },
        {
          "type": "null"
        }
      ]
    },
    "experimentDraftId": {
      "anyOf": [
        {
          "type": "string",
          "format": "uuid",
          "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
        },
        {
          "type": "null"
        }
      ]
    },
    "experimentDraftRevision": {
      "anyOf": [
        {
          "type": "integer",
          "exclusiveMinimum": 0,
          "maximum": 9007199254740991
        },
        {
          "type": "null"
        }
      ]
    },
    "source": {
      "type": "string",
      "minLength": 1,
      "maxLength": 524288
    },
    "reason": {
      "type": "string",
      "minLength": 1,
      "maxLength": 2000
    }
  },
  "required": [
    "proposalId",
    "strategyId",
    "strategyRevision",
    "baseSourceRevision",
    "baseSourceSha256",
    "datasetVersionId",
    "datasetSha256",
    "experimentDraftId",
    "experimentDraftRevision",
    "source",
    "reason"
  ],
  "additionalProperties": false
}

What comes back

Field	Description
proposalId, strategyId, sourceSha256	String identifiers and SHA-256 of the proposed source.
status	Stored proposal status; pending for a new proposal.
created	Boolean. Whether this call created the proposal.
applied, readyToRun	Both false in this tool response.
url	Relative Weavers URL for reviewing the proposal.

This table describes the decoded tool result. MCP wraps it in text content and, for object results, structuredContent.

Worked example

Fictional data. Replace identifiers, revisions and hashes with values from your own Weavers workflow.

Request

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "propose_python_source",
    "arguments": {
      "proposalId": "55555555-5555-4555-8555-555555555555",
      "strategyId": "11111111-1111-4111-8111-111111111111",
      "strategyRevision": 3,
      "baseSourceRevision": 0,
      "baseSourceSha256": null,
      "datasetVersionId": null,
      "datasetSha256": null,
      "experimentDraftId": null,
      "experimentDraftRevision": null,
      "source": "# Draft implementation for review.\n",
      "reason": "Start a clearly documented implementation."
    }
  }
}

Decoded result

{
  "proposalId": "55555555-5555-4555-8555-555555555555",
  "strategyId": "11111111-1111-4111-8111-111111111111",
  "sourceSha256": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
  "status": "pending",
  "created": true,
  "applied": false,
  "readyToRun": false,
  "url": "/eureka?strategy=11111111-1111-4111-8111-111111111111&section=build&pythonView=implementation"
}

If the request fails

Sign in and grant weavers.python_source.propose before calling this tool.
Use resources you can access and refresh revision information when it changes.
Check result.isError even when HTTP returns 200.

Find the error and next step →