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appsignal-mcp: Instructions file for Claude Code

CLAUDE.md

appsignal-mcp CLAUDE.md is an instructions file for Claude Code from pauldub/appsignal-mcp. It costs 918 tokens per session, scanned A, original, MIT.

Repository instructions for AppSignal MCP, a TypeScript server that lets an AI assistant query error-monitoring data from AppSignal.

In plain words
What is it for?
They help develop, run, test, build, and configure the server and its AppSignal error-query integration.
Why use it?
They document the project structure, configuration, commands, and available error-search tools so changes follow the existing design.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md; mentions Claude Code.

This is pauldub/appsignal-mcp's own configuration. It tells Claude Code how to work on appsignal-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything appsignal-mcp configures →

not rated 5repo 1y ago A scan 918 tokens original MIT
View source ↗ pauldub/appsignal-mcp
Reuse

Borrowing it

Nothing to install: this file belongs to pauldub/appsignal-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/pauldub/appsignal-mcp/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/pauldub/appsignal-mcp

Made for: Claude Code.

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Per session 918 This file is loaded in full into every session.
When invoked 918 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00918 $0.00918
Opus 5 $0.00459 $0.00459
Sonnet 5 $0.00184 $0.00184
Haiku 4.5 $0.00092 $0.00092

Measured 8d ago against content hash e03d69115d0d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

appsignal-mcp CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 122 lines

How it starts

The opening of the file, as written. The whole thing — 122 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

AppSignal MCP is a Model Context Protocol (MCP) server for interacting with AppSignal's error monitoring API, built with Bun, TypeScript, and the official MCP TypeScript SDK. It creates a bridge that allows Claude to directly query AppSignal error data.

Common Commands

Development

  • Start the server: bun start
  • Start with auto-reload: bun dev
  • Run tests: bun test
  • Build executable: bun run build

CLI Options

The server can be configured using command line arguments:

appsignal-mcp --appsignal-api-token your-token

Available options:

  • --appsignal-api-token <token> - AppSignal API token
  • --log-level <level> - Logging level (debug, info, warn, error)
  • --port <port> - Server port number

Code Architecture

Core Components

  1. MCP Server (src/mcp/server.ts)

    • Creates an MCP-compliant server using the official SDK
    • Registers two tools: get_error_sample and search_error_samples
    • Uses stdio transport for communication with Claude

  2. AppSignal Integration

    • src/appsignal/client.ts - Core API client for fetching error samples
    • src/appsignal/auth.ts - Handles authentication with AppSignal's API
    • src/appsignal/types.ts - TypeScript type definitions for AppSignal data structures

  3. Configuration & Utilities

    • src/utils/config.ts - Handles configuration from CLI args and env variables
    • src/utils/logger.ts - Provides logging capabilities with configurable levels

  4. Main Entry Point

    • src/index.ts - CLI interface and application bootstrapping

Data Flow

  1. User runs the MCP server with AppSignal credentials
  2. MCP server initializes and listens on stdio for commands
  3. When Claude requests error data, it sends a request to the MCP server
  4. The server authenticates with AppSignal and fetches the requested data
  5. The formatted error data is returned to Claude through the MCP protocol

Read the full file on GitHub · 122 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 122 lines · 918 tokens per session scan A e03d69115d0d

Subscribe to this mod's changes

appsignal-mcp CLAUDE.md is an instructions file published in the GitHub repository pauldub/appsignal-mcp (5 stars, last pushed 1y ago), licensed MIT. It adds 918 tokens to every session, about $0.0046 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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