API reference · Trust Fabric

Why this decision came out the way it did, and which run it belongs to

GET /fabric/decisions/{decision_id}/explain

Last reviewed 2026-11-06

GET /fabric/decisions/{decision_id}/explain

Every trajectory step and the developer portal have linked here since the trajectory work; until 2026-09-27 the route did not exist and the link 404ed.

Built only from the stored record: the stages that denied, held or could not answer, each with the detail it recorded. Nothing is re-evaluated.

Parameters

Name	In	Type	Meaning
`decision_id` required	path	string
`X-CAIN-Session`	header	string or null

Responses

Status	Meaning	Body
`200`	Successful Response	JSON
`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 onlydecision_id pathX-CAIN-Session header

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 GET 'https://cainstudio.online/fabric/decisions/<decision_id>/explain' \
  -H "X-API-Key: $CAIN_API_KEY"

import json, os, urllib.request

req = urllib.request.Request('https://cainstudio.online/fabric/decisions/<decision_id>/explain', method='GET',
    headers={"X-API-Key": os.environ["CAIN_API_KEY"]})
with urllib.request.urlopen(req, timeout=60) as r:
    print(r.status, json.load(r))

const res = await fetch("https://cainstudio.online/fabric/decisions/<decision_id>/explain", {
  method: "GET",
  headers: {
    "X-API-Key": process.env.CAIN_API_KEY!,
  },
});
console.log(res.status, await res.json());

Schemas used

Error · HTTPValidationError · ValidationError

← Retrieve one recorded decision (Evidence) · all 81 Trust Fabric calls · Check whether a recorded decision has been altered since it was written →

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