## Check whether a contact is known on a line

**get** `/api/v2/lines/contact-status`

Check whether a contact is known or new on one of your Sendblue lines.
The result uses the same message history and inactivity window as new-contact limits.
Incoming messages and outgoing messages accepted for sending count as activity; rejected requests do not.
A saved contact is not required, and activity on another line or account does not count.

The lookup does not reserve capacity. Other sending rules still apply.
Line-scoped temporary tokens can query only the lines they allow.
Only number and sendblue_number query parameters are accepted.

### Query Parameters

- `number: string`

  Contact phone number (E.164 format). Formatted phone numbers are converted to E.164; email addresses are not supported.

- `sendblue_number: string`

  Your Sendblue phone number (E.164 format). Old lines still available during a replacement grace period are also supported.

### Returns

- `LineContactStatusResponse object { classification, known_contact, new_contact_lookback_days, 4 more }`

  - `classification: "known" or "new" or "not_applicable" or "unavailable"`

    Known or new contact status. Returns not_applicable if these limits do not apply, or unavailable if Sendblue could not check the status.

    - `"known"`

    - `"new"`

    - `"not_applicable"`

    - `"unavailable"`

  - `known_contact: boolean`

    True for known, false for new, and null for not_applicable or unavailable. Other sending rules still apply.

  - `new_contact_lookback_days: number`

    Days without activity before a contact counts as new again. Null if this limit does not apply or the setting is unavailable.

  - `number: string`

    Contact phone number in E.164 format.

  - `sampled_at: string`

    When the contact status was checked in ISO 8601 UTC.

  - `sendblue_number: string`

    Sendblue phone number in E.164 format.

  - `status: "OK"`

    - `"OK"`

### Example

```http
curl https://api.sendblue.co/api/v2/lines/contact-status \
    -H "sb-api-key-id: $SENDBLUE_API_API_KEY" \
    -H "sb-api-secret-key: $SENDBLUE_API_API_SECRET"
```

#### Response

```json
{
  "classification": "known",
  "known_contact": true,
  "new_contact_lookback_days": 30,
  "number": "+14155550200",
  "sampled_at": "2026-10-06T19:00:00.000Z",
  "sendblue_number": "+14155550100",
  "status": "OK"
}
```