# HTTP: locks

Arc agent documentation

All 4 locks endpoints, with request fields and access notes.

[HTTP directory](/arc/docs/reference/http) · [Transport guide](/arc/docs/guides/http)

Request fields and access notes below are partial. Additional constraints and permissions may apply. Prefer the corresponding MCP tool and schema where available.

## GET /v1/locks

List locks.

Query field names (types and requiredness not specified here): `active_only`, `agent_id`.

## POST /v1/locks

Acquire lock.

Access: LAN writes require an active session token. Local loopback requests are exempt from this requirement by default; other permissions still apply.

### Request body fields (partial)

| Field | Type | Required | Constraints |
| --- | --- | --- | --- |
| `agent_id` | string | yes | See operation notes. |
| `file_path` | string | yes | See operation notes. |
| `ttl_sec` | integer | no | At least 5 seconds. |
| `metadata` | object | no | See operation notes. |

Other constraints may apply, including for fields marked optional.

## POST /v1/locks/refresh

Refresh lock.

Access: LAN writes require an active session token. Local loopback requests are exempt from this requirement by default; other permissions still apply.

### Request body fields (partial)

| Field | Type | Required | Constraints |
| --- | --- | --- | --- |
| `agent_id` | string | yes | See operation notes. |
| `file_path` | string | yes | See operation notes. |
| `ttl_sec` | integer | no | At least 5 seconds. |

Other constraints may apply, including for fields marked optional.

## POST /v1/locks/release

Release lock.

Access: LAN writes require an active session token. Local loopback requests are exempt from this requirement by default; other permissions still apply.

### Request body fields (partial)

| Field | Type | Required | Constraints |
| --- | --- | --- | --- |
| `agent_id` | string | yes | See operation notes. |
| `file_path` | string | yes | See operation notes. |

Other constraints may apply, including for fields marked optional.