> ## Documentation Index
> Fetch the complete documentation index at: https://docs.redpill.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Receipts

> A signed receipt is a per-response transparency log that binds your request and response hashes to the attested gateway.

A receipt is the gateway's signed record of one request. It is an ordered event log that captures
what the gateway received, which upstream it selected and verified, what it forwarded, and what it
returned, with a hash at each step. The gateway signs the receipt with a key published in its
[attestation report](/confidential-ai/attestation-report), so a verified receipt proves the response
came from the attested workload and was not altered.

Every inference response includes the receipt id in the `x-receipt-id` header. Fetch the receipt:

```bash theme={null}
curl "https://api.redpill.ai/v1/aci/receipts/$RECEIPT_ID" \
  -H "Authorization: Bearer $API_KEY"
```

`{id}` accepts the receipt id (`rcpt-…`) or the response `id` (chat id). See
[`GET /v1/aci/receipts/{id}`](/api-reference/receipts) for the response shape.

## What a receipt commits to

`GET /v1/aci/receipts/{id}` returns the receipt directly, signed by a key from the attested keyset:

| Field                                   | Meaning                                                                               |
| --------------------------------------- | ------------------------------------------------------------------------------------- |
| `receipt_id`, `chat_id`                 | The receipt id and the response/chat id.                                              |
| `workload_id`, `workload_keyset_digest` | Must match the attestation report you verified.                                       |
| `endpoint`, `method`, `served_at`       | The route, HTTP method, and time served.                                              |
| `event_log`                             | The ordered transparency events below.                                                |
| `signature`                             | Signature over the receipt, by a `receipt_signing_keys` entry in the attested keyset. |

The `event_log` carries the two hashes that matter most: `request.received.body_hash` (the request
the gateway observed) and `response.returned.wire_hash` (the response it returned). Comparing these to
the bytes you sent and received proves the receipt covers your exact exchange.

<Note>
  The legacy alias `GET /v1/signature/{id}` returns the same receipt wrapped in a compatibility envelope
  that adds a `text` field (`"<request body hash>:<response hash>"`), a top-level `signature`, and
  `signing_address`, for earlier API clients. New integrations should use the canonical
  `/v1/aci/receipts/{id}` response above.
</Note>

## The transparency event log

The `event_log` records the request's path through the gateway. Each event carries a hash or a fact,
never your prompt text.

| Event                            | Author   | What it records                                                        |
| -------------------------------- | -------- | ---------------------------------------------------------------------- |
| `request.received`               | Frontend | Hash of the request body the gateway observed.                         |
| `middleware.forwarded`           | Frontend | Effective body hash after any middleware rewrite.                      |
| `route.selected`                 | Backend  | The target route id the backend accepted.                              |
| `request.forwarded`              | Backend  | Hash of the provider-facing request body.                              |
| `transparency.request_modified`  | Backend  | Present when the forwarded body differs from the received body.        |
| `upstream.verified`              | Backend  | The upstream verification result and binding (see below).              |
| `response.received`              | Backend  | The provider response before any post-processing.                      |
| `transparency.response_modified` | Backend  | Present when the returned response differs from the received response. |
| `response.returned`              | Frontend | `cleartext_hash` and `wire_hash` of the final response.                |

The `request.received.body_hash` and `response.returned.wire_hash` are the two values combined into
the signed `text`. That is what lets you prove the signature covers the exact bytes you sent and
received.

## The `upstream.verified` event

This event tells you whether the model that ran your prompt was itself attested:

```json theme={null}
{
  "type": "upstream.verified",
  "provider": "near-ai",
  "model_id": "Qwen/Qwen3.6-35B-A3B-FP8",
  "url_origin": "https://cloud-api.near.ai",
  "verifier_id": "private-ai-verifier/near-ai-gateway/v1",
  "result": "verified",
  "required": true,
  "session_id": "as_3681736b33b9b8191216968e37e350bf…"
}
```

* For a [confidential model](/confidential-ai/confidential-models), `result` is `verified`,
  `required` is `true`, and `session_id` references the
  [attested session](/confidential-ai/attested-sessions) the channel was bound to.
* For a routed model, `result` is `failed`, `required` is `false`, and there is no `session_id`. The
  gateway still served the request, but the upstream provider was not attested.

## Why hashes, not bodies

The gateway does not store your request or response. Receipts hold hashes, so they prove integrity
without warehousing your data. If the response
was modified in transit, a `transparency.*_modified` event records that the forwarded bytes differed,
again by hash.

## Streaming

For streaming responses the gateway can return `x-receipt-id` early, but the signed receipt is
complete only after the stream finishes, because `response.returned.wire_hash` covers the full
streamed body. Fetch the receipt after the stream ends.

## Next

<CardGroup cols={2}>
  <Card title="Attested sessions" icon="link" href="/confidential-ai/attested-sessions">
    Follow `session_id` to the verified security context behind a confidential response.
  </Card>

  <Card title="Verify a response" icon="circle-check" href="/guides/verify-a-response">
    Check a receipt signature and hashes yourself.
  </Card>
</CardGroup>