# Create an API access token {#top}

**Change** · `POST /v1/access-tokens` · MCP tool `issue-access-token`

Creates a long-lived token for scripts and MCP clients. Send it in the `X-Tarsana-Access-Token` header. The token is shown only once, so copy it now; if you lose it, create a new one and revoke the old one. A token cannot create, list or revoke tokens, and it expires at `expires_at`. You need to be signed in with a session to create one.

Roles that can call it: `viewer`, `builder`, `deployer`.

## Parameters

| Name | In | Required | Description |
|---|---|---|---|
| `token_label` | body | no | Optional: a name for this token, so that you can tell your tokens apart |

## Returns

A JSON object with these keys: `access_token`, `token_id`, `token_label`, `login`, `carrier`, `scopes`, `tenants`, `issued_at`, `expires_at`, `guarantee`, `caller_authenticated`.

## Example request

```sh
curl -X POST https://api.tarsana.io/v1/access-tokens \
  -H "X-Tarsana-Session: $SESSION" \
  -H "Content-Type: application/json" \
  --data '{"token_label": "laptop-mcp"}'
```

## Example response

```json
{
  "access_token": "YOUR-ACCESS-TOKEN",
  "token_id": "67e94a06c977c24c",
  "token_label": "laptop-mcp",
  "login": "you@example.com",
  "carrier": "X-Tarsana-Access-Token",
  "scopes": [
    "operate",
    "read",
    "submit"
  ],
  "tenants": [
    "acme"
  ],
  "issued_at": "2026-10-05T02:15:39Z",
  "expires_at": "2027-01-03T02:15:39Z",
  "guarantee": "namespaces are separated, callers are not authenticated",
  "caller_authenticated": false
}
```

## Errors

| Code | HTTP | What it means |
|---|---|---|
| [`invalid_parameter`](/api/errors#invalid_parameter) | 400 | A value in your request does not have the expected format, for example a submission ID that is not a spec hash. Check the value against the field's description and try again. |
| [`unauthenticated`](/api/errors#unauthenticated) | 401 | Your request has no credential, or one that Tarsana does not recognise. Sign in with `login`, or send a valid access token. |
| [`forbidden`](/api/errors#forbidden) | 403 | Your role does not allow this operation. The response names the roles that do; ask for a credential with one of them. |
| [`rate_limited`](/api/errors#rate_limited) | 429 | You sent too many requests in a short time. Wait for the number of seconds in `retry_after_seconds`, then try again. |
| [`surface_fault`](/api/errors#surface_fault) | 500 | Something went wrong on our side. Try again later, and contact Tarsana support if it keeps happening. |