# N-central MCP Server

An [MCP](https://modelcontextprotocol.io) server for the N-able N-central REST API
(API-Service). N-central is an RMM: it monitors MSP-managed devices organised as org units
(system > service organizations > customers > sites), raises monitoring issues and runs
scheduled tasks. This server lets an AI agent browse the org unit hierarchy, devices, assets,
lifecycle data, service status, active issues, scheduled tasks, custom properties, maintenance
windows and access groups and, on explicit request, run a script on a device, change custom
properties or lifecycle data, add or delete maintenance windows, and create access groups.

- Transport: MCP Streamable HTTP at `POST /mcp`, health probe at `GET /health`
- Stateless and multi-tenant: the server URL and token arrive on every request as HTTP headers
  and are never stored; every tool is listed from the first `tools/list`
- Python 3.12, [uv](https://docs.astral.sh/uv/), FastMCP, httpx
- License: Apache-2.0, Copyright 2026 MSPbots.ai

## Authentication headers

| Header | Required | Type | Default | Allowed values | Description | Example |
|---|---|---|---|---|---|---|
| `X-Ncentral-Server-Url` | Yes | string | none | https URL | Root URL of the N-central server (a trailing `/api` is ignored) | `https://ncentral.example.com` |
| `X-Ncentral-Jwt` | Yes | string | none | - | N-central User-API Token (JWT) of an API-only user | `your-jwt` |

Where to get it: create an API-only user in N-central with the roles and access groups the agent
should have (MFA must be off for that user), then in the N-central UI open Administration > User
Management > Users > the user > API Access > Generate JSON Web Token. The token acts with that
user's permissions.

How the token is sent to N-central: on each MCP request the JWT is exchanged once for a
short-lived access token (`POST {server}/api/auth/authenticate` with `Authorization: Bearer
<JWT>`); API calls then send `Authorization: Bearer <access token>`. The access token is kept
only for that one request.

A request to `/mcp` without both headers gets HTTP 401; a server URL that is not https gets
HTTP 400.

## Tools

All tools return a JSON string. Paged lists take `pageNumber` (from 1), `pageSize` (default 50,
max 1000), `sortBy` and `sortOrder` (`asc` / `desc`; `ascending`, `natural`, `descending` and
`reverse` are also accepted) and add `summary {count, total, page, total_pages, has_more,
next_page}`. Customer and site ids are org unit ids.

| Tool | Purpose | Parameters (required in **bold**) |
|---|---|---|
| `ncentral_navigate` | Describe the tool areas (changes nothing) | domain (`system`, `orgs`, `devices`, `monitoring`, `tasks`, `custom-properties`, `maintenance`, `access-groups`) |
| `ncentral_status` | Check the server and JWT and list the areas | - |
| `ncentral_health` | API-Service liveness (server time) | - |
| `ncentral_server_info` | N-central and API-Service versions | - |
| `ncentral_validate_token` | Check the access token works | - |
| `ncentral_list_service_orgs` | Service organizations | paging |
| `ncentral_list_customers` | Customers, optionally of one service organization | soId, paging |
| `ncentral_get_customer` | One customer | **customerId** |
| `ncentral_list_sites` | Sites, optionally of one customer | customerId, paging |
| `ncentral_get_site` | One site | **siteId** |
| `ncentral_list_org_units` | Every org unit with type and parent | paging |
| `ncentral_get_org_unit` | One org unit | **orgUnitId** |
| `ncentral_list_org_unit_children` | Org units under an org unit | **orgUnitId**, paging |
| `ncentral_get_registration_token` | Agent registration token (a secret) | **kind** (`customer` / `site` / `org-unit`), **id** |
| `ncentral_list_devices` | Devices, optionally through a saved filter | filterId, paging |
| `ncentral_get_device` | One device | **deviceId** |
| `ncentral_get_device_assets` | Asset inventory record | **deviceId** |
| `ncentral_get_device_lifecycle` | Warranty / lease / purchase data | **deviceId** |
| `ncentral_update_device_lifecycle` | Change lifecycle fields (**write**) | **deviceId**, **data** {warrantyExpiryDate, leaseExpiryDate, expectedReplacementDate, purchaseDate, cost, location, assetTag, description} |
| `ncentral_get_device_service_status` | State of each monitoring service | **deviceId** |
| `ncentral_list_devices_by_org_unit` | Devices of a customer or site | **orgUnitId**, paging |
| `ncentral_list_device_filters` | Saved device filters | paging |
| `ncentral_list_active_issues` | Active issues of a customer or site | **orgUnitId**, paging |
| `ncentral_list_job_statuses` | Job statuses of an org unit | **orgUnitId** |
| `ncentral_list_device_tasks` | Scheduled tasks of a device | **deviceId** |
| `ncentral_get_task` | One scheduled task | **taskId** |
| `ncentral_get_task_status` | Status counts of a task | **taskId** |
| `ncentral_get_task_status_details` | Status and output per device | **taskId** |
| `ncentral_create_direct_task` | Run a script / automation policy on one device now (**write**) | **name**, **deviceId**, **itemId**, **taskType** (`AutomationPolicy` / `Script` / `MacScript`), **customerId**, **credential** {**type** (`LocalSystem` / `DeviceCredentials` / `CustomCredentials`), username, password}, parameters [{**name**, value, description, type}] |
| `ncentral_list_org_custom_properties` | Custom properties of an org unit | **orgUnitId**, paging |
| `ncentral_get_org_custom_property` | One org unit custom property | **orgUnitId**, **propertyId** |
| `ncentral_update_org_custom_property` | Set an org unit custom property (**write**) | **orgUnitId**, **propertyId**, **value** |
| `ncentral_list_device_custom_properties` | Custom properties of a device | **deviceId** |
| `ncentral_get_device_custom_property` | One device custom property | **deviceId**, **propertyId** |
| `ncentral_update_device_custom_property` | Set a device custom property (**write**) | **deviceId**, **propertyId**, **value** |
| `ncentral_list_maintenance_windows` | Maintenance windows of a device | **deviceId** |
| `ncentral_add_maintenance_windows` | Add windows to devices (**write**) | **deviceIds**, **windows** [{**name**, **type**, **cron**, **duration**, **enabled**, **applicableAction**, reboot options}] |
| `ncentral_delete_maintenance_windows` | Delete device-level patch windows (**write**, needs `confirm: true`) | **scheduleIds**, confirm |
| `ncentral_list_access_groups` | Access groups of an org unit | **orgUnitId**, paging |
| `ncentral_get_access_group` | One access group | **accessGroupId** |
| `ncentral_create_device_access_group` | Group giving users access to devices (**write**) | **orgUnitId**, **groupName**, **groupDescription**, deviceIds, userIds |
| `ncentral_create_org_unit_access_group` | Group giving users access to org units (**write**) | **orgUnitId**, **groupName**, **groupDescription**, orgUnitIds, userIds, autoIncludeNewOrgUnits (`true` / `false`) |

Errors come back as a JSON envelope instead of an exception:

```json
{"error": {"code": "unauthorized", "message": "N-central rejected the User-API Token (JWT). ...", "retryable": false}}
```

`code` is one of `not_configured`, `unauthorized`, `not_found`, `invalid_argument`,
`rate_limited`, `upstream_error`. Reads are retried with backoff on 429, 5xx and network
errors; writes are retried only on 429. An expired access token is renewed once automatically.

## Run locally

```bash
uv sync
uv run python -m ncentral_mcp          # listens on 0.0.0.0:8080
```

or with Docker:

```bash
docker build --platform linux/amd64 -t ncentral-mcp:dev .
docker run --rm -p 8080:8080 ncentral-mcp:dev
```

Configuration (environment variables, all optional): `MCP_HTTP_HOST` (default `0.0.0.0`),
`MCP_HTTP_PORT` (default `8080`), `LOG_LEVEL` (default `INFO`). Credentials are never read from
the environment.

## Testing example

```bash
# list tools
curl -s http://localhost:8080/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "X-Ncentral-Server-Url: https://ncentral.example.com" \
  -H "X-Ncentral-Jwt: your-jwt" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

# active issues of one customer
curl -s http://localhost:8080/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "X-Ncentral-Server-Url: https://ncentral.example.com" \
  -H "X-Ncentral-Jwt: your-jwt" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"ncentral_list_active_issues","arguments":{"orgUnitId":100}}}'
```

Unit tests (no network access needed):

```bash
uv run pytest
```

## Delivery notes

- **Tool count (42).** Kept as is because the tool names and camelCase parameter names are an
  existing contract.
- **API contract.** Requests follow N-able's published N-central REST API reference
  (`https://developer.n-able.com/n-central`). Many endpoints are marked preview there; their
  behaviour can change between N-central releases.
- **Removed parameters.** Paging parameters were dropped from tools whose endpoints are not
  paged: `ncentral_list_device_custom_properties`, `ncentral_list_maintenance_windows`,
  `ncentral_list_device_tasks`, `ncentral_list_job_statuses` and
  `ncentral_get_task_status_details`.
- **Direct tasks.** The API requires a description and type for each parameter; when omitted
  they default to the parameter name and `string`.
- **Maintenance windows.** Each window is checked for the required fields before anything is
  sent; deleting needs `confirm: true` and only removes device-level patch windows.
- **Annotations.** Read tools are annotated read-only; lifecycle and custom property updates are
  annotated as overwriting existing values.

## License

Apache License 2.0 - see [LICENSE](LICENSE) and [NOTICE](NOTICE).