# Oeis (npm · @pipeworx/mcp-oeis)

OEIS (On-Line Encyclopedia of Integer Sequences) MCP. Authoritative database of integer sequences.…

- Trust score: 83/100 (high trust)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `gateway.pipeworx.io`: 85/100, [markdown](https://verifymcp.io/servers/pipeworx-io-oeis/oeis-mcp.md), [page](https://verifymcp.io/servers/pipeworx-io-oeis/oeis-mcp)
- npm · `@pipeworx/mcp-oeis`: 83/100 (this document), [markdown](https://verifymcp.io/servers/pipeworx-io-oeis/pipeworx-mcp-oeis.md), [page](https://verifymcp.io/servers/pipeworx-io-oeis/pipeworx-mcp-oeis)

## Channel facts

- Registry: `npm`
- Package: `@pipeworx/mcp-oeis`
- Version: `0.2.1`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Supply Chain Security**: 100/100
  - No malware found by supply-chain analysis.
  - No known CVEs affecting this package version or its production dependencies.
  - No install/post-install scripts declared.
  - No production dependencies, so there is no dependency health to assess.
- **Provenance & Transparency**: 97/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to pipeworx-io/mcp-oeis).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 1 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 69/100
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 402 tokens (~201/item across 2 items; 2 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 23/100
  - Stability observed for 7 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 2 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 3 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the Oeis MCP server?

Oeis runs locally as an npm package, launched with npx -y @pipeworx/mcp-oeis. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add pipeworx-io-oeis -- npx -y @pipeworx/mcp-oeis
```

### Cursor

```json
{
  "mcpServers": {
    "pipeworx-io-oeis": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-oeis"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "pipeworx-io-oeis": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-oeis"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add pipeworx-io-oeis -- npx -y @pipeworx/mcp-oeis
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "pipeworx-io-oeis": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "@pipeworx/mcp-oeis"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add pipeworx-io-oeis --command npx --arg -y --arg @pipeworx/mcp-oeis
```

### Hermes

```yaml
mcp_servers:
  pipeworx-io-oeis:
    command: "npx"
    args: ["-y", "@pipeworx/mcp-oeis"]
```

### Netclaw

```json
{
  "McpServers": {
    "pipeworx-io-oeis": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "@pipeworx/mcp-oeis"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add pipeworx-io-oeis -t stdio -c npx -a -y @pipeworx/mcp-oeis
```

### Other

```json
{
  "mcpServers": {
    "pipeworx-io-oeis": {
      "command": "npx",
      "args": [
        "-y",
        "@pipeworx/mcp-oeis"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-04 (score 83, +16)

- [security improvement] Malware scan: unverified → pass

### 2026-11-03 (score 67, −13)

- [security regression] Malware scan: pass → unverified
- [functional improvement] Stability: unverified → 0.17
- [functional] Package version: 0.2.0 → 0.2.1

### 2026-10-30 (score 80, 0)

- [functional regression] Security disclosure: unverified → fail

### 2026-10-29 (score 80)

First indexed and scored.

## MCP tools (2)

### `search_sequence` (~207 tokens)

Search the OEIS (On-Line Encyclopedia of Integer Sequences), the authoritative database of integer sequences. Identify a sequence from its first terms by passing a comma-separated list of integers (e.g. "1,1,2,3,5,8" finds the Fibonacci numbers), look up a specific sequence by A-number (e.g. "A000045"), or search free-text keywords (e.g. "prime gaps"). Returns up to 10 matching sequences per page with their A-number, name, terms, keywords, author, and offset. Use the start argument to paginate (10 results at a time).

Input parameters:

- `query` (string, required): A comma-separated list of integers (e.g. "1,1,2,3,5,8"), an A-number (e.g. "A000045"), or free-text keywords (e.g. "prime gaps").
- `start` (number): Pagination offset; results come 10 at a time. Default 0.

### `get_sequence` (~142 tokens)

Fetch a single OEIS integer sequence by its A-number (e.g. "A000045" for the Fibonacci numbers, "A000040" for the primes). Accepts the A-number with or without the "A" prefix and zero-padding ("A000045", "45", and "000045" are all valid). Returns the full record: name, terms (data), comments, formulas, keywords, offset, author, and reference count. Use this to get the formula or mathematical description of a known sequence.

Input parameters:

- `id` (string, required): An OEIS A-number such as "A000045", or just "45" / "000045".

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/pipeworx-io-oeis/pipeworx-mcp-oeis#diagnostics

## Score history

- 2026-11-05: 83
- 2026-11-04: 83
- 2026-11-03: 67
- 2026-11-02: 80
- 2026-11-01: 80
- 2026-10-31: 80
- 2026-10-30: 80
- 2026-10-29: 80

## Common questions

### What is the Oeis MCP server?

Oeis is an MCP server listed in the public MCP registry as io.github.pipeworx-io/oeis. OEIS (On-Line Encyclopedia of Integer Sequences) MCP. Authoritative database of integer sequences.… This page covers its npm package (@pipeworx/mcp-oeis).

### Is the Oeis MCP server safe to use?

Oeis scores 83 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 5 November 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Oeis MCP server expose?

Oeis exposes 2 tools: search_sequence, get_sequence. Their descriptions and schemas cost roughly 349 tokens of context every time the server is loaded.

### Is the Oeis MCP server still maintained?

Oeis is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the Oeis MCP server under?

Oeis declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- npm package: https://www.npmjs.com/package/@pipeworx/mcp-oeis
- Socket report: https://socket.dev/npm/package/@pipeworx/mcp-oeis
- Repository: https://github.com/pipeworx-io/mcp-oeis
- Website: https://pipeworx.io/packs/oeis
- Changelog RSS feed: https://verifymcp.io/servers/pipeworx-io-oeis/pipeworx-mcp-oeis.xml
- Changelog JSON feed: https://verifymcp.io/servers/pipeworx-io-oeis/pipeworx-mcp-oeis.json
- HTML version of this page: https://verifymcp.io/servers/pipeworx-io-oeis/pipeworx-mcp-oeis