API reference · CAIN 16 MCP Enforcement

L5 Authorize

POST /fabric/mcp/l5/authorize

Last reviewed 2026-10-02

POST /fabric/mcp/l5/authorize

Authorize a tool call through the L5 identity + dynamic authority fabric (Prompt 2).

Request body

L5AuthorizeRequest (required)

Field	Type	Meaning
`tenant` required	string
`agent_id` required	string
`tool_name` required	string
`arguments`	object
`caller_assertion`	object or null

Responses

Status	Meaning	Body
`200`	Successful Response	object
`422`	Validation Error	`HTTPValidationError`
`401`	No key, or a key that is not valid	JSON `detail`
`429`	Rate limit for your plan reached; retry after the Retry-After seconds	JSON `detail`

Try it

Your API key X-API-Key Remember the key in this tab onlyRequest 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/l5/authorize' \
  -H "X-API-Key: $CAIN_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"tenant": "tenant", "agent_id": "agent-id", "tool_name": "tool-name"}'

import json, os, urllib.request

req = urllib.request.Request('https://cainstudio.online/fabric/mcp/l5/authorize', method='POST',
    headers={"X-API-Key": os.environ["CAIN_API_KEY"], "Content-Type": "application/json"},
    data=json.dumps({
      "tenant": "tenant",
      "agent_id": "agent-id",
      "tool_name": "tool-name"
    }).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/l5/authorize", {
  method: "POST",
  headers: {
    "X-API-Key": process.env.CAIN_API_KEY!,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "tenant": "tenant",
    "agent_id": "agent-id",
    "tool_name": "tool-name"
  }),
});
console.log(res.status, await res.json());

Schemas used

HTTPValidationError · L5AuthorizeRequest · ValidationError

← Enforce · all 2 CAIN 16 MCP Enforcement calls

Try CAIN-42 on your own agents

Create a free account and every new account starts with a 7-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