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Receipts and sessions are the two response-level artifacts you use after verifying the gateway attestation report.
  • A receipt is the signed record for one response.
  • A session is the immutable verified security context for a confidential upstream channel.

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Receipt Lifecycle

Every inference response includes x-receipt-id. Fetch it with Get Receipt: 
curl "https://inference.phala.com/v1/aci/receipts/$RECEIPT_ID" \
  -H "Authorization: Bearer $API_KEY"
The receipt records ordered events with hashes and facts, not prompt text.
EventWhat it records
request.receivedHash of the request body observed by the gateway.
route.selectedSelected backend route.
request.forwardedHash of the provider-facing request.
upstream.verifiedProvider verification result, channel binding, claims, and session_id.
response.receivedHash of the provider response before post-processing.
response.returnedHash of the final wire response.

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What a Receipt Proves

A verified receipt proves:
  1. The receipt was signed by a key in the attested gateway keyset.
  2. workload_id and workload_keyset_digest match the attestation report.
  3. The returned response bytes match response.returned.wire_hash.
  4. The upstream verification result for that response is recorded.

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Streaming Responses

For streaming, x-receipt-id can arrive before the stream ends. Fetch the receipt after the stream completes because response.returned.wire_hash covers the full response body.

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Attested Sessions

When the gateway verifies a confidential upstream, it records an attested session. A receipt references it from upstream.verified.session_id. A session captures:
  • Verified upstream identity and endpoint.
  • Enforced channel binding.
  • Typed claims and reasons.
  • Evidence digest and evidence payload.
The session_id is content-addressed. If the verified material changes, the session id changes.

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Trace a Response

response -> x-receipt-id
receipt  -> upstream.verified.session_id
session  -> provider identity, binding, claims, evidence
For most applications, the receipt has enough data to decide whether a response was confidential. Fetch the session when you need deeper audit evidence.

Verify a Response

TCB and Claims