API reference · CAG-L5 System Governor

Evolution Propose

POST /fabric/mcp/system/{tenant}/evolution/propose

Last reviewed 2026-11-06

POST /fabric/mcp/system/{tenant}/evolution/propose

Agent-signed EvolutionProposal (MODEL | TOOL_CONFIGURATION). Unsigned -> 401, nothing recorded.

Parameters

Name	In	Type	Meaning
`tenant` required	path	string

Request body

ProposeBody (required)

Field	Type	Meaning
`proposal` required	object
`evaluation_report`	object

Responses

Status	Meaning	Body
`200`	Successful Response	object
`401`	The X-API-Key header is missing, or the key is unknown, revoked or replaced.	`Error`
`403`	The key is valid but may not do this (for example an agent key approving its own held action).	`Error`
`422`	Validation Error	`HTTPValidationError`
`429`	Rate limit or monthly quota reached. Wait for the number of seconds in Retry-After when it is sent.	`Error`

Try it

Your API key X-API-Key Remember the key in this tab onlytenant pathRequest body application/json

This call changes data in the account the key belongs to.

The request goes from your browser straight to this site. Your key is not stored unless you tick the box, and then only in this tab's session storage.

Code

curl -sS -X POST 'https://cainstudio.online/fabric/mcp/system/<tenant>/evolution/propose' \
  -H "X-API-Key: $CAIN_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"proposal": {}}'

import json, os, urllib.request

req = urllib.request.Request('https://cainstudio.online/fabric/mcp/system/<tenant>/evolution/propose', method='POST',
    headers={"X-API-Key": os.environ["CAIN_API_KEY"], "Content-Type": "application/json"},
    data=json.dumps({
      "proposal": {}
    }).encode())
with urllib.request.urlopen(req, timeout=60) as r:
    print(r.status, json.load(r))

const res = await fetch("https://cainstudio.online/fabric/mcp/system/<tenant>/evolution/propose", {
  method: "POST",
  headers: {
    "X-API-Key": process.env.CAIN_API_KEY!,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "proposal": {}
  }),
});
console.log(res.status, await res.json());

Schemas used

Error · HTTPValidationError · ProposeBody · ValidationError

← Governance Key · all 2 CAG-L5 System Governor calls

Try CAIN-42 on your own agents

Create a free account and every new account starts with a 30-day trial of the full platform. Or try the sandbox first, with no account at all.

Create a free account → · Try the sandbox · See the whole ecosystem