GET /v1/receipt/{session

Fetch a Session Receipt by session id. Fully public, no authentication required.

Returns the Session Receipt v1 JSON for a given session id. This endpoint is fully public: no authentication, no token, no expiry. The URL is permanent.

It is the A2A verification endpoint and the shareable-link primitive for Session Receipts. Any client (human, browser, agent, crawler) can fetch this URL programmatically and verify the receipt locally.

Request

GET /v1/receipt/{session_id}

No headers required. No authentication.

Path parameters

Name	Description
`session_id`	The session id to fetch

Response shapes

200 OK

{
  "type": "treeship/session-receipt/v1",
  "session": { ... },
  "participants": { ... },
  "agent_graph": { ... },
  "timeline": [...],
  "side_effects": { ... },
  "artifacts": [...],
  "merkle": { ... },
  "render": { ... }
}

The body is the raw receipt.json stored at upload time, returned verbatim. See the Session Receipts concept page for the full schema.

Response headers include:

Content-Type: application/json
Cache-Control: public, max-age=86400, immutable

The immutable cache directive reflects the fact that a receipt for a given session_id never changes. PUT is idempotent for the owning dock, and cross-dock overwrites are rejected with 403, so byte equality is guaranteed for the lifetime of the session id.

403 Forbidden

{ "error": "session still open" }

Returned when a row exists for this session_id but no receipt has been uploaded yet. This shape lets A2A consumers distinguish "session exists but is still running" from "no such session".

404 Not Found

{ "error": "session not found" }

Returned when no row exists for this session_id.

Local verification

Fetching the receipt from the hub is a convenience. The trust anchor is running treeship package verify against the downloaded bytes:

# Fetch
curl -o receipt.json https://api.treeship.dev/v1/receipt/ssn_42e740bd9eb238f6

# Place it inside a .treeship directory so the verifier can read it
mkdir -p verify-work/ssn.treeship
mv receipt.json verify-work/ssn.treeship/

# Verify offline
treeship package verify verify-work/ssn.treeship

If receipt.json has been tampered with, the determinism and merkle_root checks will FAIL. A serving hub cannot forge a passing result.

Example

curl https://api.treeship.dev/v1/receipt/ssn_42e740bd9eb238f6

# Programmatic fetch for A2A trust filtering
curl -sS https://api.treeship.dev/v1/receipt/$SESSION_ID \
  | jq '.participants.total_agents, .merkle.root'

Share URLs of the form https://treeship.dev/receipt/<session_id> in blog posts, dashboards, pull requests, and incident reports. Every recipient can fetch without auth and verify locally. No keys, no tokens, no expiry.

GET /v1/receipt/{session_id}

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