# Loggerhead > Your coding agent reads your app's logs, metrics, and traces. Loggerhead is a native macOS app that receives OpenTelemetry logs, metrics, and traces on your own Mac and shows them in one window. It stores every record in a DuckDB file on your disk, and it serves the same data to your AI coding tool over the Model Context Protocol. No telemetry leaves the machine. Loggerhead is for the developer who runs the application, not for an operations team. It replaces a Docker stack of collector, database, and dashboard with one app you install from a disk image. Platform: macOS 15+ ยท Apple silicon & Intel. Free: $0 forever. Pro: $39 one-time, for one person on their own Macs, with one year of updates. Lifetime: $89 one-time, Pro with every future release. The app is not a hosted service and has no account. There is no public API: the MCP server listens on 127.0.0.1 inside the app. ## Start here - [What Loggerhead is](https://getloggerhead.com/docs/getting-started/introduction/index.md): what the app does, who it is for, and what it is not. - [Install the Mac app](https://getloggerhead.com/docs/getting-started/install-the-mac-app/index.md): download the disk image and open the app. - [Connect your first app](https://getloggerhead.com/docs/getting-started/connect-your-first-app/index.md): point an OpenTelemetry exporter at the receiver. - [Workspaces and environments](https://getloggerhead.com/docs/getting-started/workspaces-and-environments/index.md): one workspace per project with its own port pair, one environment per deployment with its own database, split on the deployment.environment.name tag. - [Set up the MCP server](https://getloggerhead.com/docs/mcp-server/setup/index.md): give Claude Code, Cursor, or Codex a window into the running application. ## Getting started - [Introduction](https://getloggerhead.com/docs/getting-started/introduction/index.md): What Loggerhead is, who it is for, and what it is not. - [Install the Mac app](https://getloggerhead.com/docs/getting-started/install-the-mac-app/index.md): Download Loggerhead, move it to Applications, and open it. The app starts its own engine. - [Connect your first app](https://getloggerhead.com/docs/getting-started/connect-your-first-app/index.md): Pick a source inside Loggerhead, or point an app that speaks OpenTelemetry at the root receiver. - [Ports and the effective port](https://getloggerhead.com/docs/getting-started/ports-and-the-effective-port/index.md): Each workspace owns a port pair: 4317/4318 for the first, 4319/4320 for the second. When a port is busy, the receiver moves along a fixed ladder. Always copy the port the app shows now. - [Workspaces and environments](https://getloggerhead.com/docs/getting-started/workspaces-and-environments/index.md): One workspace per project, one environment per deployment. Each workspace owns a port pair, each environment owns a database, and the app reads one environment at a time. ## Send telemetry - [Send OpenTelemetry from Next.js to your Mac](https://getloggerhead.com/docs/send-telemetry/nextjs/index.md): Add instrumentation.ts, point OTEL_EXPORTER_OTLP_ENDPOINT at the Loggerhead receiver, and read the traces and metrics of your Next.js app in one window. - [Send OpenTelemetry from FastAPI to your Mac](https://getloggerhead.com/docs/send-telemetry/fastapi/index.md): Install the OpenTelemetry distro, run uvicorn under opentelemetry-instrument, and read the logs, metrics, and traces of your FastAPI app in one window. - [Send OpenTelemetry from Rails to your Mac](https://getloggerhead.com/docs/send-telemetry/rails/index.md): Add the OpenTelemetry gems, write one initializer, and read the traces of your Rails app in one window. - [Send OpenTelemetry from Laravel to your Mac](https://getloggerhead.com/docs/send-telemetry/laravel/index.md): Install the OpenTelemetry PHP extension and the Laravel auto-instrumentation, set four environment variables, and read your Laravel traces in one window. - [Send OpenTelemetry from Go to your Mac](https://getloggerhead.com/docs/send-telemetry/go/index.md): Wire the OTLP exporter in main.go, wrap your HTTP handler with otelhttp, and read the traces of your Go service in one window. - [Send OpenTelemetry from Docker Compose to your Mac](https://getloggerhead.com/docs/send-telemetry/docker-compose/index.md): A container cannot reach 127.0.0.1 on the host. Point OTEL_EXPORTER_OTLP_ENDPOINT at host.docker.internal and read your container's telemetry in one window. - [Send OpenTelemetry from Kubernetes to your Mac](https://getloggerhead.com/docs/send-telemetry/kubernetes/index.md): A cluster cannot reach your laptop. Send the pods to a collector in the cluster, and forward that collector to Loggerhead over a tunnel. ## Collectors - [Collector topology: one root, many branches](https://getloggerhead.com/docs/collectors/topology-root-and-branches/index.md): Loggerhead runs one OTLP receiver, the root, inside the app. Every other collector is a branch that forwards into it. - [Docker branch example](https://getloggerhead.com/docs/collectors/docker-branch-example/index.md): Run the standard OpenTelemetry Collector in Docker as a branch that forwards to the root on your Mac. - [Kubernetes branch](https://getloggerhead.com/docs/collectors/kubernetes-branch/index.md): Run a branch collector inside a cluster and forward to the root on your Mac through a tunnel. - [Per-collector attribution](https://getloggerhead.com/docs/collectors/per-collector-attribution/index.md): Every record carries the ID of the collector that sent it, so you always know where data came from. ## Telemetry linting - [What it checks](https://getloggerhead.com/docs/telemetry-linting/what-it-checks/index.md): Loggerhead reads what your app emits and points at the noise, the leaks, and the gaps before production bills you for them. - [Tune the rules](https://getloggerhead.com/docs/telemetry-linting/tune-the-rules/index.md): Every lint rule has a row on the Rules tab of the Linting page: a toggle, its thresholds, its exceptions, and a reset. The settings belong to the workspace. - [Fixes you hand to your AI tool](https://getloggerhead.com/docs/telemetry-linting/one-click-fixes/index.md): Every finding carries a written fix. Copy it into the AI tool in your project and let the agent change the code. - [Before production checklist](https://getloggerhead.com/docs/telemetry-linting/before-production-checklist/index.md): Run this list on staging traffic before a release. Each item maps to a finding kind. - [Set up an AI provider](https://getloggerhead.com/docs/telemetry-linting/ai-providers/index.md): AI analysis uses Apple Intelligence on the Mac, or a cloud model through an Anthropic-compatible or an OpenAI-compatible API, such as OpenRouter. ## Connect your AI tool - [Claude Code](https://getloggerhead.com/docs/connect-your-ai-tool/claude-code/index.md): Give Claude Code a window into your running app through the Loggerhead MCP server. - [Cursor](https://getloggerhead.com/docs/connect-your-ai-tool/cursor/index.md): Give Cursor a window into your running app through the Loggerhead MCP server. - [Codex](https://getloggerhead.com/docs/connect-your-ai-tool/codex/index.md): Give Codex a window into your running app through the Loggerhead MCP server. - [Windsurf](https://getloggerhead.com/docs/connect-your-ai-tool/windsurf/index.md): Give Windsurf a window into your running app through the Loggerhead MCP server. - [Other MCP clients](https://getloggerhead.com/docs/connect-your-ai-tool/other-mcp-clients/index.md): Any client that speaks the Model Context Protocol over stdio can use the Loggerhead server. - [Connect your project with one prompt](https://getloggerhead.com/docs/connect-your-ai-tool/connect-your-project-with-one-prompt/index.md): Paste one prompt into your AI tool. It sends the project's logs, metrics, and traces to Loggerhead and checks the result through the MCP server. ## MCP server - [Set up the MCP server](https://getloggerhead.com/docs/mcp-server/setup/index.md): Give Claude Code, Cursor, Codex, or any MCP client a window into your running app. - [What the server exposes](https://getloggerhead.com/docs/mcp-server/what-the-server-exposes/index.md): Nine tools that read, seven tools that change the lint rules, one tool that marks a finding fixed, and one resource, all served from the data on your Mac. - [Tools reference](https://getloggerhead.com/docs/mcp-server/tools-reference/index.md): Parameters and defaults for the 17 Loggerhead MCP tools: nine that read, seven that change the lint rules, and one that marks a finding fixed. - [Privacy and local access](https://getloggerhead.com/docs/mcp-server/privacy-and-local-access/index.md): The engine binds loopback by default. What changes when you expose it, and what never leaves your Mac. ## Reference - [Local endpoints](https://getloggerhead.com/docs/reference/http-api/index.md): What the app serves on loopback: the MCP endpoint and a health probe. - [Settings](https://getloggerhead.com/docs/reference/settings/index.md): Every setting the app stores, its key, and its default. - [Glossary](https://getloggerhead.com/docs/reference/glossary/index.md): Every term this documentation uses, in plain words: OTLP, span, collector, cardinality, MCP, and the rest. - [Operations runbook](https://getloggerhead.com/docs/reference/operations-runbook/index.md): Where the data lives, how to reset it, and what to do when something does not show up. ## Compare - [Loggerhead vs Grafana, Loki, and Tempo](https://getloggerhead.com/docs/compare/grafana-loki-tempo/index.md): An honest comparison of Loggerhead with the Grafana, Loki, Tempo, and Prometheus stack in Docker: what the stack does better, what one Mac app does better, and where each one stops. - [Loggerhead vs Jaeger](https://getloggerhead.com/docs/compare/jaeger/index.md): An honest comparison of Loggerhead with Jaeger: Jaeger is the reference trace UI and runs anywhere; Loggerhead joins traces with logs and metrics on one time base, on one Mac. - [Loggerhead vs SigNoz](https://getloggerhead.com/docs/compare/signoz/index.md): An honest comparison of Loggerhead with SigNoz on this Mac: SigNoz is a production platform on ClickHouse that also runs locally; Loggerhead is a desktop app with no containers. ## Optional - [Every documentation page as one file](https://getloggerhead.com/llms-full.txt): the whole of the documentation in one download. - [Documentation home](https://getloggerhead.com/docs/): the same pages as HTML, with search. - [Pricing](https://getloggerhead.com/#pricing): what Free and Pro each include. - [Download](https://getloggerhead.com/download): the newest build for macOS. - [Changelog](https://getloggerhead.com/changelog): what changed in each release. - [Site map for agents](https://getloggerhead.com/sitemap.md): every page on the site, as Markdown.