> Tychron Atlas API & Provisioning Reference — chapter 4 of 35 as Markdown. Web version: https://docs.tychron.com/api-reference/number-inventory/
> Source: https://docs.tychron.com/api-reference/ · Updated 2026-08-12 · Generated from the Atlas OpenAPI spec (https://api.atlas.tychron.online/api/v1/openapi is the live contract; this file is a dated snapshot of it).
> Source revision: atlas_api_reference_2026-08-12.md · sha256 482ebd3b014af053 · sanitize gate v1 clean · reconciled with OpenAPI 2026.8.25-p01 (spec sha256 cc049ef38c71cd6e) on 2026-09-05 · content last modified 2026-09-09 · newer definition under review since 2026-09-09 (not yet reconciled)
> Scope: the Atlas platform API only. The SMS, MMS, CNAM, LRN and MCL services are separate APIs with their own specifications: https://docs.tychron.com/openapi/
> Machine index: https://docs.tychron.com/llms.txt

# Number Inventory

### Coverage

```http
GET /api/v1/number_inventory/{type}/coverage HTTP/1.1
```

Searches inventory coverage.


__Path Parameters__

| Name | Type                               | Description               |
| ---- | ---------------------------------- | ------------------------- |
| type | Enum(`TENDLC`, `TOLLFREE`):String! | Either TENDLC or TOLLFREE |

__Query Parameters__

| Name        | Type                   | Description                        |
| ----------- | ---------------------- | ---------------------------------- |
| npa         | String                 | [Query Desc. npa](https://docs.tychron.com/api-reference/number-inventory/#desc-1)         |
| nxx         | String                 | [Query Desc. nxx](https://docs.tychron.com/api-reference/number-inventory/#desc-2)         |
| state       | String                 | [Query Desc. state](https://docs.tychron.com/api-reference/number-inventory/#desc-3)       |
| rate_center | String                 | [Query Desc. rate_center](https://docs.tychron.com/api-reference/number-inventory/#desc-4) |
| count_by    | [Enum](https://docs.tychron.com/api-reference/number-inventory/#enum-5):String | [Query Desc. count_by](https://docs.tychron.com/api-reference/number-inventory/#desc-6)    |

#### Query Desc. npa {#desc-1}

A simplified format of the pattern, where only the NPA (Area Code) is provided.

This field can be used in conjuction with the `nxx` field to form a NPANXX pattern
internally.

#### Query Desc. nxx {#desc-2}

A simplified format of the pattern, where only the NXX (Exchange Code) is provided.

This field can be used in conjuction with the `npa` field to form a NPANXX pattern
internally.

#### Query Desc. state {#desc-3}

A state code used to filter on, it can be used in conjuction with rate_center typically.

#### Query Desc. rate_center {#desc-4}

A rate center's code used to filter the coverage.

#### Enum Values count_by {#enum-5}

Allowed values

* `STATE`
* `RATE_CENTER`
* `NPA_NXX`
* `BLOCK`

#### Query Desc. count_by {#desc-6}

What should the coverage group its results by, the default is NPA_NXX.

#### Request

```http
GET /api/v1/number_inventory/{type}/coverage HTTP/1.1
Accept: application/json
```
#### Response 200

##### application/json

```http
HTTP/1.1 200
Content-Type: application/json
Content-Length: 453
```

```json
{
  "data": {
    "count": 10,
    "items": [
      {
        "block": "9",
        "count": 101,
        "lata": "236",
        "npa": "202",
        "nxx": "201",
        "rate_center": "WSHNGTNZN1",
        "state": "DC",
        "type": "TENDLC"
      }
    ],
    "search_params": {
      "count_by": "npa_nxx",
      "npa": "202",
      "nxx": "201",
      "rate_center": "WSHNGTNZN1",
      "state": "DC"
    }
  },
  "type": "number_inventory"
}
```
#### Response 403

##### application/json

```http
HTTP/1.1 403
Content-Type: application/json
Content-Length: 312
```

```json
{
  "errors": [
    {
      "code": "access_denied.no_scope",
      "detail": "No scope available to user role",
      "params": {
        "action": "index",
        "level": "guest",
        "resource": "resource"
      },
      "sub_code": "none",
      "title": "Access Denied, no scope available"
    }
  ]
}
```

---

Previous chapter: https://docs.tychron.com/api-reference/api.md  
Next chapter: https://docs.tychron.com/api-reference/ordering-system-reference.md  
Complete reference in one file: https://docs.tychron.com/llms-full.txt