API reference · CAIN Trajectory

Evaluate Action

POST /fabric/trajectories/{trajectory_id}/evaluate

Last reviewed 2026-10-02

POST /fabric/trajectories/{trajectory_id}/evaluate

Evaluate whether an action is allowed without recording it. Simulation endpoint - does not mutate trajectory state.

Parameters

Name	In	Type
`trajectory_id` required	path	string
`action`	query	string or null
`tool`	query	string or null
`resource`	query	string or null
`intent`	query	string or null
`policy_id`	query	string or null

Request body

EvaluateActionRequest 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 onlytrajectory_id pathaction querytool queryresource queryintent querypolicy_id queryRequest 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/trajectories/<trajectory_id>/evaluate' \
  -H "X-API-Key: $CAIN_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"action": "action"}'

import json, os, urllib.request

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

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

Schemas used

EvaluateActionRequest · HTTPValidationError · ValidationError

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