How do I install Signalint?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Signalint need an API key?

No required environment variable is listed on this record.

What transport does Signalint use?

Signalint runs locally over stdio.

When was Signalint last checked?

Last checked 2026-11-09. Local stdio MCP server for cached, loop-aware JS/TS diagnostics (Oxlint, tsc, Biome, ESLint).

Signalint MCP server

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

npx -y [email protected]

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1claude mcp add io.github.tranqui004-signalint -- npx -y signalint-mcp@1.2.1

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "io.github.tranqui004-signalint": {4      "command": "npx",5      "args": [6        "-y",7        "[email protected]"8      ]9    }10  }11}

claude_desktop_config.json

Local · npmPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 1.2.1
Last checked

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

Signalint

Signalint is a reliable, read-only-by-default diagnostic intelligence layer for AI coding agents (Claude Code, Cursor, Codex, VS Code) and CI workflows.

Instead of flooding an agent's context window with thousands of raw compiler lines, Signalint normalizes diagnostics across compilers, linters, and language servers into bounded, priority-clustered issue summaries, calculates verification deltas against explicit baselines, and detects oscillating fix loops.

Key Differentiators

13 Complete MCP Tools: From incremental checks and immutable snapshots to live diagnostic ingestion and journaled transactional fix application.
Verification Deltas: Exact arithmetic on introduced, resolved, and unchanged diagnostics with semantic identity matching that survives line shifts.
Immutable Snapshots & Concurrency Safety: Isolated in-memory snapshot store keyed by checkId eliminates race collisions during concurrent checks.
Monorepo-Aware Planning: Unites package manifests (pnpm-workspace.yaml) parsed via pure-JS YAML with glob negation exclusions and TypeScript Project References, ordering checks topologically.
Multi-Source Provenance: Distinguishes compiler, linter, and editor/LSP diagnostics across JavaScript, TypeScript, Python (Ruff/Mypy), Rust (Clippy), and Go (GolangCI-Lint).
Portable Host Hooks: Native verify-after-change adapters for Claude Code, Cursor, Codex, and VS Code.
In-Memory Previews & In-Process Rollback: In-memory previews never touch disk; apply uses per-file adjacent temporary-file replacement, pre-write drift detection, and in-process best-effort rollback for multi-file writes (does not claim persistent crash recovery if aborted abruptly).

Quick Start

1. Requirements

Node.js >= 22.12.0 (utilizes native node:sqlite).
Your project installs its own diagnostic engines (typescript, oxlint, eslint, and/or @biomejs/biome). Signalint detects project-local installations and ships no bundled engines.

2. Initialize in your repository

npx signalint init

This detects your project's linters/compilers, generates signalint.config.json, and configures your installed MCP clients.

3. Add to MCP Clients

Add Signalint to your MCP configuration (e.g. claude_desktop_config.json, .cursor/mcp.json):

{
  "mcpServers": {
    "signalint": {
      "command": "npx",
      "args": ["-y", "signalint-mcp"]
    }
  }
}

Complete MCP Tools Catalog

Signalint exposes 13 strictly typed MCP tools over stdio:

Tool	Category	Safety Annotation	Description
`ping`	Diagnostics	Read-only (`idempotent`)	Verifies server responsiveness and canonical project root path.
`check_project`	Diagnostics	Read-only (`idempotent`)	Full project/workspace scan across all enabled engines.
`check_files`	Diagnostics	Read-only (`idempotent`)	Fast incremental check on specific files using content-hash caching.
`get_issue_detail`	Diagnostics	Read-only (`idempotent`)	Retrieves full, unomitted issue records anchored to an immutable `checkId`.
`get_loop_status`	Diagnostics	Read-only (`idempotent`)	Returns oscillating fix signatures and rule churn detected in the session.
`get_diagnostic_snapshot`	Snapshots	Read-only (`idempotent`)	Retrieves complete state and metrics for an immutable check snapshot.
`compare_diagnostics`	Deltas	Read-only (`idempotent`)	Computes verification delta between a baseline check and a current check.
`after_edit_check`	Deltas	Read-only (`idempotent`)	Runs incremental check on edited files and diffs against a baseline check.
`ingest_diagnostics`	Live / LSP	Read-only (`openWorld: false`)	Ingests external LSP or compiler diagnostics into Signalint's clustering model.
`get_live_diagnostics`	Live / LSP	Read-only (`idempotent`)	Returns active buffered diagnostics with source provenance.
`preview_diagnostic_fix`	Transactions	Read-only (`destructive: false`)	Stages proposed code fixes in-memory.

See docs/mcp-contract.md for full JSON Schemas and error codes.

CLI Commands

Signalint includes a comprehensive command-line interface:

# Run a project diagnostic scan:
npx signalint check .
npx signalint check src/ --format github    # GitHub Actions annotations

# View session statistics and cache economics:
npx signalint stats

# Verify local engine availability and configuration:
npx signalint doctor

# Manage host verify-after-change hooks:
npx signalint hooks preview --runtime claude
npx signalint hooks install --runtime cursor --confirm
npx signalint hooks run --runtime claude --payload '<json-event>'

Monorepo Support

Signalint natively understands multi-package monorepos:

Configure "monorepoMode": "auto" in signalint.config.json to detect pnpm-workspace.yaml via pure-JS YAML parsing with glob negation exclusions (!).
Strictly differentiates local workspace packages (workspace:*) from external npm registry dependencies.
Builds a topological dependency graph uniting package manifests and TypeScript project references.
Caches whole-program TypeScript builds in isolated per-package directories (.signalint/cache/tsc/<project-id>/).
Changes to a shared package automatically invalidate dependent packages while keeping independent siblings cached.

See docs/monorepo.md for configuration and architecture.

Verify-After-Change Hooks

Automate post-edit verification without creating infinite agent loops:

Native adapters for Claude Code, Cursor, Codex, and VS Code.
Emits bounded context into prompt windows and blocks only on unresolved syntax/type errors.

See docs/hooks.md for setup instructions.

Signalint

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Signalint?

Does Signalint need an API key?

What transport does Signalint use?

When was Signalint last checked?

Documentation

Signalint

Key Differentiators

Quick Start

1. Requirements

2. Initialize in your repository

3. Add to MCP Clients

Complete MCP Tools Catalog

CLI Commands

Monorepo Support

Verify-After-Change Hooks

Documentation Index

License