An Alibi is the public record of one purchase an AI agent made under a Keelson mandate. This guide checks a real one, from a purchase paid on the PayPal sandbox, against production.

{% walkthrough %}
{% steps %}
{% step title="Take a real Alibi" file="verify.sh" lines="1-2" %}
This Alibi was issued on 9 November 2026 and is committed to the repository as a test fixture, so it never changes under you.
{% /step %}
{% step title="Send it to the verifier" file="verify.sh" lines="4-8" %}
`POST /v1/alibis/verify` runs the browser verifier's checks against pinned trust roots and a public Arbitrum RPC. It needs no account, and it stores nothing.
{% /step %}
{% step title="Read the verdict" file="verify.sh" lines="9-11" %}
`verified 2of2` means both TEE legs, Intel TDX and AWS Nitro, countersigned this purchase, and every check that applies to it passed.
{% /step %}
{% step title="Do it from code" file="verify.ts" lines="5-12" %}
The same request from TypeScript. The idempotency key makes a retry the same request.
{% /step %}
{% step title="See what was checked" file="response.json" lines="4-12" %}
Each check names one thing it proves: the mandate's passkey, both attestations, the countersignature, inclusion in the public log, the witnesses and the anchor on chain. Checks for features this purchase did not use, such as zero-knowledge proofs, are `absent`.
{% /step %}
{% step title="Trust no server" file="verify.sh" lines="1-2" %}
Download [the same file](/samples/01M6ZWZJHWRRHQEYNJAT7NMSV8.alibi) and drop it on [verify.keelson.finance](https://verify.keelson.finance). The checks run in your browser against roots pinned in its code; only the chain reads leave your machine.
{% /step %}
{% /steps %}
{% files %}
```sh {% file="verify.sh" check="verify-one-command" %}
# A real Alibi from the PayPal sandbox, countersigned by both TEEs
ALIBI=https://raw.githubusercontent.com/DavidZapataOh/keelson-paypal/main/packages/alibi/test/fixtures/01M6ZWZJHWRRHQEYNJAT7NMSV8.alibi

curl -sL "$ALIBI" \
| curl -s https://api.keelson.finance/v1/alibis/verify \
    -H 'content-type: application/vnd.keelson.alibi.v1+json' \
    -H "idempotency-key: docs-$RANDOM$RANDOM" \
    --data-binary @- \
| jq -r '"\(.verdict) \(.mode)"'

# expect: ^verified 2of2$
```
```ts {% file="verify.ts" %}
const alibi = await fetch(
  "https://raw.githubusercontent.com/DavidZapataOh/keelson-paypal/main/packages/alibi/test/fixtures/01M6ZWZJHWRRHQEYNJAT7NMSV8.alibi",
).then((r) => r.arrayBuffer());

const res = await fetch("https://api.keelson.finance/v1/alibis/verify", {
  method: "POST",
  headers: {
    "content-type": "application/vnd.keelson.alibi.v1+json",
    "idempotency-key": crypto.randomUUID(),
  },
  body: alibi,
});

const { verdict, mode, checks } = await res.json();
console.log(verdict, mode); // verified 2of2
```
```json {% file="response.json" %}
{
  "verdict": "verified",
  "mode": "2of2",
  "checks": [
    {
      "id": "bundle.format",
      "status": "pass"
    },
    {
      "id": "leaf.view",
      "status": "pass"
    },
    {
      "id": "qr.leaf",
      "status": "absent"
    },
    {
      "id": "mandate.challenge",
      "status": "pass"
    },
    {
      "id": "mandate.passkey",
      "status": "pass"
    },
    {
      "id": "mandate.credentials",
      "status": "pass"
    },
    {
      "id": "tee.attestation.tdx",
      "status": "pass"
    },
    {
      "id": "tee.attestation.nitro",
      "status": "pass"
    },
    {
      "id": "tee.countersign",
      "status": "pass"
    },
    {
      "id": "tee.registry",
      "status": "pass"
    },
    {
      "id": "policy.replay",
      "status": "pass"
    },
    {
      "id": "log.policy",
      "status": "pass"
    },
    {
      "id": "log.inclusion",
      "status": "pass"
    },
    {
      "id": "log.witnesses",
      "status": "pass"
    },
    {
      "id": "anchor.consistency",
      "status": "pass"
    },
    {
      "id": "anchor.root",
      "status": "pass"
    },
    {
      "id": "anchor.tx",
      "status": "pass"
    },
    {
      "id": "timestamps",
      "status": "pass"
    },
    {
      "id": "zk.c1",
      "status": "absent"
    },
    {
      "id": "zk.c3",
      "status": "absent"
    },
    {
      "id": "evidence.manifest",
      "status": "pass"
    },
    {
      "id": "evidence.web_fact",
      "status": "absent"
    },
    {
      "id": "evidence.checkout",
      "status": "absent"
    },
    {
      "id": "evidence.conversion",
      "status": "absent"
    },
    {
      "id": "paypal.ids",
      "status": "pass"
    },
    {
      "id": "card.authorizations",
      "status": "absent"
    }
  ]
}
```
{% /files %}
{% /walkthrough %}

## In your browser

The command above asks Keelson's API to run the checks. To trust no Keelson server at all, download [the same Alibi](/samples/01M6ZWZJHWRRHQEYNJAT7NMSV8.alibi) and drop it on [verify.keelson.finance](https://verify.keelson.finance). The page runs every check in your browser against trust roots pinned in its code; it reads the chain from a public Arbitrum RPC that you can replace with your own.

## What each check means

Each row is one check the verifier runs, the party whose signature or record it rests on, and how it came out for this Alibi.

| Check | What it checks | Who answers for it | This Alibi |
| --- | --- | --- | --- |
| `bundle.format` | Bundle format | Keelson | Passed |
| `leaf.view` | Log leaf matches the bundle | Keelson | Passed |
| `qr.leaf` | Matches the QR link | Keelson | Not used by this purchase |
| `evidence.manifest` | Evidence manifest | Agent operator | Passed |
| `evidence.web_fact` | Store's product endpoint, notarized (TLSNotary) | Keelson | Not used by this purchase |
| `evidence.checkout` | Checkout total and its breakdown | Agent operator | Not used by this purchase |
| `evidence.conversion` | Currency conversion within the mandate's spread | Agent operator | Not used by this purchase |
| `paypal.ids` | PayPal ids | Keelson | Passed |
| `card.authorizations` | Card charges approved by both TEEs | Keelson | Not used by this purchase |
| `mandate.challenge` | Mandate challenge | User | Passed |
| `mandate.passkey` | User's passkey signature | User | Passed |
| `mandate.credentials` | Mandate credentials | Keelson | Passed |
| `tee.attestation.tdx` | Intel TDX attestation | Keelson | Passed |
| `tee.attestation.nitro` | AWS Nitro attestation | Keelson | Passed |
| `tee.registry` | Signers registered on-chain | Keelson | Passed |
| `tee.countersign` | TEE countersignature | Keelson | Passed |
| `policy.replay` | Policy decision replayed with Cedar | Keelson | Passed |
| `log.policy` | Log policy is the pinned one | Keelson | Passed |
| `log.inclusion` | Included in the log | Keelson | Passed |
| `log.witnesses` | Witness cosignatures | Witnesses | Passed |
| `anchor.consistency` | Anchor consistent with the log | Keelson | Passed |
| `anchor.root` | Root anchored on-chain | Arbitrum | Passed |
| `anchor.tx` | Anchor transaction | Arbitrum | Passed |
| `timestamps` | RFC 3161 timestamps | Timestamp authorities | Passed |
| `zk.c1` | Zero-knowledge proof | Keelson | Not used by this purchase |
| `zk.c3` | Signed by a registered user, anonymously | Arbitrum | Not used by this purchase |

{% callout type="caution" title="Sandbox and testnet" %}
The purchase was paid on the PayPal sandbox and its bond lives on Arbitrum Sepolia. The TEEs, the public log and its witnesses run in production.
{% /callout %}