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

# A2A AgentCard Export

> One-way projection of the canonical alignment card into the A2A AgentCard envelope, with the AAP attestation token attached as an A2A extension.

The **A2A AgentCard export** is a public-discovery surface that projects a Mnemom-composed canonical alignment card into the [A2A AgentCard](https://github.com/google/A2A) v1.x envelope. The endpoint is **unauthenticated**: any consumer can fetch it; per-agent opt-in keeps the surface explicit.

The export is **one-way**. Mnemom doesn't accept inbound A2A registration in v1; that's deferred to a future phase. The export pattern is the standard "publish for discovery" half of A2A.

## Endpoint

```
GET /v1/agents/{agent_id}/a2a-agent-card
```

| Property       | Value                                                                                                                                |
| -------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| Auth           | None — public surface                                                                                                                |
| Per-agent gate | `agents.a2a_export_enabled` — when false, the endpoint returns **404 (not 403)** to avoid leaking which agents exist on the platform |
| Caching        | `Cache-Control: public, max-age=60, stale-while-revalidate=300`                                                                      |
| ETag           | `"sha256:<canonical content_hash>"` — clients can issue `If-None-Match` for cheap revalidation                                       |
| CORS           | `*` — the endpoint is intentionally cross-origin                                                                                     |

## What the projection includes

```json theme={null}
{
  "schemaVersion": "1.0",
  "name": "support-agent",
  "description": "Mnemom-composed alignment card declaring deliberation_before_action, policy_attentiveness, evidence_grounded.",
  "url": "https://mnemom.ai/v1/agents/smolt-e2ca60ef",
  "version": "1.17.0",
  "capabilities": { "streaming": false, "pushNotifications": false },
  "skills": [
    { "id": "campfire_create_chart_account", "name": "campfire_create_chart_account" }
  ],
  "extensions": [
    {
      "uri": "https://aap.mnemom.ai/v1/attestation",
      "required": false,
      "body": {
        "token": "<jws-compact>",
        "jwks_uri": "https://mnemom.ai/v1/.well-known/jwks.json"
      }
    },
    {
      "uri": "https://aap.mnemom.ai/v1/alignment",
      "required": false,
      "body": { "autonomy_mode": "observe", "values": { "declared": [...] }, "principal": {...} }
    }
  ],
  "metadata": {
    "content_hash": "<sha256-hex>",
    "composed_at": "2026-05-22T12:00:00Z"
  }
}
```

| Field                         | Source                                                                           |
| ----------------------------- | -------------------------------------------------------------------------------- |
| `name`                        | `principal.identifier` from the alignment card; falls back to `agent_id`         |
| `description`                 | Care-framed summary of the first six declared values                             |
| `version`                     | `1.<canonical version>.0` (semver shape)                                         |
| `skills`                      | First 50 entries of `autonomy.bounded_actions`                                   |
| `extensions[aap/attestation]` | Present when `AAP_ATTESTATION_SIGNING_ENABLED=true`; soft-omits on signing error |
| `extensions[aap/alignment]`   | Public-safe subset of the canonical card                                         |

## What the projection deliberately excludes

The public-discovery surface filters operator-internal fields:

* `card_id` (smolt-internal)
* `_composition.source_card_id` / `_composition.source_policy_id`
* `field_provenance` (caller-aware redaction is server-side; A2A consumers don't get a redacted view, they get no view)
* Internal connector grants beyond the bare tool name surface

If you'd benefit from the full composed view including provenance, use `GET /v1/agents/{id}/state` under an authenticated principal.

## Opt-in

Agents default to **opted out**. An org admin flips the per-agent flag:

```bash theme={null}
curl -X PUT https://api.mnemom.ai/v1/agents/<agent_id>/settings \
  -H "Authorization: Bearer $MNEMOM_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"a2a_export_enabled": true}'
```

Once flipped, the AgentCard is live within seconds. Flipping back returns to 404 immediately (the per-request flag check happens on every fetch).

## Verifying the embedded attestation

Any A2A consumer can extract the `extensions[aap/attestation].body.token` and verify it offline against the published JWKS. The [`mnemom verify-card`](/guides/verify-card) CLI does this for you in one command:

```bash theme={null}
mnemom verify-card smolt-e2ca60ef
```

For programmatic verification, the wire format is [documented](/specifications/attestation-token); any JOSE/JWT library that supports EdDSA can verify.

## See also

* [AAP attestation tokens](/concepts/aap-attestation) — the JWS extension
* [Transparency log](/concepts/transparency-log) — durable historic verification
* [`mnemom verify-card`](/guides/verify-card) — offline verification CLI
* [Card lifecycle](/concepts/card-lifecycle) — where the export fits in the lifecycle