# Switchboard

> Programmable reverse proxy rules, written in Go, compiled to WebAssembly, and hot-swapped without restarts.

## Docs

- [What is Switchboard?](/): Programmable reverse proxy rules, written in Go, compiled to WebAssembly, and hot-swapped without restarts.
- [Quickstart](/quickstart): Build, test, deploy, and serve your first Switchboard rule in five minutes, no object store required.

## Concepts

- [Architecture](/concepts/architecture): How the CLI, registry, and proxy fit together, and what happens between a deploy and the first request served by the new rule.
- [Bundles, channels & revisions](/concepts/bundles-and-channels): The deployment model: content-addressed bundles, mutable channel pointers, and an append-only revision history.
- [Security & reliability](/concepts/reliability): The failure model: activation gates, quarantine, durable last-known-good, fail modes, and why a broken rule can't take the proxy down.

## Guides

- [Writing rules](/guides/writing-rules): The Go SDK: reading requests, returning actions, patching headers, and composing logic with chains.
- [Bundle data files](/guides/data-files): Ship read-only lookup tables inside a bundle: allowlists, redirect maps, cohort tables, hashed into identity and exposed to the rule.
- [Testing rules](/guides/testing): Declare a behavioral contract in tests.yaml, run it with switchboard test, and poke at bundles with eval.
- [Replaying production traffic](/guides/replay): Feed captured Caddy access logs through two bundles and diff every decision before you deploy.
- [Deploying & operating](/guides/deploying): Deploy bundles, inspect history, promote between channels, and roll back. Every operation is append-only and reversible.
- [Caddy integration](/guides/caddy): Run Switchboard as a Caddy handler module: configuration, observability, and routing on rule decisions.
- [Standalone & embedded](/guides/standalone): Run switchboard serve as a single-binary proxy, or embed the engine as middleware in any Go HTTP server.
- [Registries](/guides/registries): Choose and configure a registry backend: S3-compatible object storage, a local directory, or a read-only HTTPS origin.

## Reference

- [CLI](/reference/cli): Every switchboard command and flag.
- [switchboard.yaml](/reference/switchboard-yaml): The project config file: every field, plus environment variable expansion and the S3 credential variables.
- [Caddyfile directives](/reference/caddyfile): Every directive of the switchboard handler block, with defaults.
- [SDK](/reference/sdk): The github.com/ethndotsh/switchboard/sdk package: request accessors, action constructors, builders, and Chain.
- [Test schema](/reference/tests): The switchboard.tests/v1 schema: every request and expect field in tests.yaml.
- [Bundle format](/reference/bundle-format): The switchboard.descriptor/v1 descriptor, the identity zone, and the on-registry object layout.
- [Observability](/reference/observability): The status endpoint, Prometheus metrics, and per-request decision fields in access logs.

## Changelog

- [Switchboard v0.2.1](/changelog/v0-2-1)
- [Switchboard v0.2.0](/changelog/v0-2-0)
- [Switchboard v0.1.0](/changelog/v0-1-0)
- [Switchboard v0.0.3](/changelog/v0-0-3)
- [Switchboard v0.0.2](/changelog/v0-0-2)
- [Switchboard v0.0.1](/changelog/v0-0-1)