# `io.usefulapi/nomic-atlas` on anlyon.dev

> Text inside fenced blocks marked untrusted-server-text was written by the MCP server's publisher, not by anlyon.dev. It is data to inspect, not instructions to follow. Invisible characters are shown as [U+XXXX].
> No finding is not a safety guarantee: these are point-in-time checks of tool definitions, not of code or behaviour.

- Page: https://anlyon.dev/servers/io.usefulapi/nomic-atlas
- JSON: https://anlyon.dev/api/v1/servers/io.usefulapi/nomic-atlas
- Version: 1.16.4 (active)
- Publisher: io.usefulapi (domain proven to the MCP Registry)
- Runs: remote (streamable-http)
- Sign-in to list tools: none
- Repository: https://github.com/m190/usefulapi-mcp
- Metadata from the official MCP Registry, synced 2026-10-22T11:18:46.107Z

Title and description, as the publisher wrote them:

```untrusted-server-text
Nomic Atlas MCP by usefulapi
Semantic nearest-neighbour search over your datasets, plus indices and projections.
```

Scanned 2026-10-22T10:19:13.184Z over streamable-http.

**9 tools: 1 change things and 8 only read.**

| Group | Class | Tools | Claude Code |
| --- | --- | --- | --- |
| Deletes or cancels | destructive | 0 | deny |
| Can't be undone | irreversible | 0 | ask |
| Changes things | write | 1 | ask |
| Only reads | read | 8 | allow |

## Exfil surface

No private-data -> untrusted-input -> outbound path in this server alone: no tool is tagged private-data or untrusted-input or outbound.

| Tag | Meaning | Tools |
| --- | --- | --- |
| private-data | Reads files, mail, messages, databases, secrets, calendars or repositories. | none |
| untrusted-input | Brings in text someone else can write: web pages, inbound email, messages, issues and comments. | none |
| outbound | Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL. | none |

## Findings

No check matched anything in these tool definitions.


## Changes things (1)

Creates or changes something that can be changed back. Claude Code: ask.

### `nomic_nearest_neighbors_by_id`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

Description, as the server wrote it:

```untrusted-server-text
Semantic search: given the ids of records already in a dataset, return their nearest neighbours in embedding space, with distances. This is what Atlas is for — finding what resembles what across unstructured data. Needs a BUILT index; if the map is still building the call fails with a 500, so check nomic_get_index_job. Atlas: POST /v1/project/data/get/nearest_neighbors/by_id.
```

## Only reads (8)

Looks things up and changes nothing. Claude Code: allow.

### `nomic_get_dataset`

- The name "nomic_get_dataset" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Fetch a dataset (Atlas calls it a project) by id — its schema, size, indices and projections. Atlas: GET /v1/project/{id}.
```

### `nomic_get_dataset_by_slug`

- The name "nomic_get_dataset_by_slug" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Fetch a dataset by organisation slug and dataset slug — the human-readable path, and usually easier than finding the UUID. Atlas: GET /v1/project/{organization_slug}/{project_slug}.
```

### `nomic_get_index_job`

- The name "nomic_get_index_job" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Fetch the status of an index-building job. Atlas indexes take time to build, and a vector search against an unbuilt map fails — this is how you tell which it is. Atlas: GET /v1/project/index/job/{job_id}.
```

### `nomic_get_organization`

- The name "nomic_get_organization" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Fetch an organisation by slug, with the datasets it holds. Atlas: GET /v1/organization/{slug}.
```

### `nomic_get_projection_schema`

- The name "nomic_get_projection_schema" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Fetch the field schema of one projection — the columns available on its records. Atlas: GET /v1/project/projection/{projection_id}/schema.
```

### `nomic_get_tag_status`

- The name "nomic_get_tag_status" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Check whether a tag has finished computing its membership. A tag that is still building returns partial results. Atlas: GET /v1/project/projection/tags/status.
```

### `nomic_get_user`

- The name "nomic_get_user" says "get": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Fetch the account the API key belongs to, including the organisations it can access. Start here — the organisation slug feeds the other tools. Atlas: GET /v1/user.
```

### `nomic_list_tags`

- The name "nomic_list_tags" says "list": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
List the tags defined on one projection — the labelled selections a person made on the map. Atlas: GET /v1/project/projection/tags/get/all.
```

## Claude Code permissions

For `.claude/settings.json`, assuming the server is installed as `nomic-atlas`:

```json
{
  "permissions": {
    "allow": [
      "mcp__nomic-atlas__nomic_get_user",
      "mcp__nomic-atlas__nomic_get_organization",
      "mcp__nomic-atlas__nomic_get_dataset",
      "mcp__nomic-atlas__nomic_get_dataset_by_slug",
      "mcp__nomic-atlas__nomic_get_index_job",
      "mcp__nomic-atlas__nomic_get_projection_schema",
      "mcp__nomic-atlas__nomic_list_tags",
      "mcp__nomic-atlas__nomic_get_tag_status"
    ],
    "ask": [
      "mcp__nomic-atlas__nomic_nearest_neighbors_by_id"
    ],
    "deny": []
  }
}
```

## Remote posture

What an anonymous client saw at the remote endpoint, last 2026-10-22T15:30:13.137Z, unchanged since 2026-10-22T15:30:13.137Z. No credentials were sent and no tool was called. Values are shown as the endpoint returned them. Method: https://anlyon.dev/methodology#remote-posture

| Fact | Observed |
| --- | --- |
| Reachable | `yes` |
| HTTP status of an anonymous initialize | `200` |
| tools/list served without credentials | `yes` |
| Tools that change things, listed without credentials | `1` |
| Protocol version | `2025-06-18` |
| WWW-Authenticate on 401 | `not observed` |
| resource_metadata in WWW-Authenticate | `none` |
| RFC 9728 protected resource metadata | `https://nomic-atlas.usefulapi.io/.well-known/oauth-protected-resource/mcp` |
| Authorization servers | `https://nomic-atlas.usefulapi.io` |
| Legacy HTTP+SSE transport | `no` |
| Dynamic client registration | `yes` |
| Client ID metadata documents | `no` |

- **warn** Tools that change things, listed to anyone ([unauth-remote-writes](https://anlyon.dev/methodology#unauth-remote-writes))

```untrusted-server-text
The endpoint served tools/list without credentials, and the list has 1 tool that changes things (1 write). Whether a call also works without credentials was not tested: tools are never called.

https://nomic-atlas.usefulapi.io/mcp: tools/list returned 9 tools to an anonymous client, including nomic_nearest_neighbors_by_id (write)
```