# signatures.prepare

Start signing an agreement in your own portal session. Only you can, interactively; agents can't sign for you.

`POST /api/v1/contractor/signatures.prepare`

Permissions: `contractor:read`, `contractor:write` · Roles: contractor · Send `expectedRevision`

**INTERACTIVE_SIGNATURE_REQUIRED.** The contractor signs or declines in their own portal session. API and MCP calls are refused with a portalUrl to the agreement.

Not available over MCP: The named contractor signs or declines in person, after verifying again.

## Fields

| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `id` | string (ID) | Yes | The record's ID. |
| `expectedRevision` | integer | Yes | The record's current revision, from the last time you read it. If someone changed the record since, the request is refused with a conflict so you can reload and check before trying again. at most 9007199254740991; greater than 0. |

## Example request

```bash
curl https://app.getoatmilk.com/api/v1/contractor/signatures.prepare \
  -H "Authorization: Bearer $OATMILK_OAUTH_TOKEN" \
  -H "X-Accounting-Organization: $OATMILK_ORGANIZATION_ID" \
  -H "Content-Type: application/json" \
  -d '{
  "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d",
  "expectedRevision": 3
}'
```

Reference page: https://app.getoatmilk.com/docs/api/contractor/signatures.prepare