Show HN: acplause – An ACP agent for OpenAI-compatible APIs

acplause is an Agent Client Protocol v2 agent. Your editor talks to it over stdio; it thinks with any OpenAI-compatible Chat Completions API, OpenRouter first, and works in your workspace through tools.

Inspired by acp-bridge, which serves as a behavioral reference for the tool loop, limits and error handling. acplause follows the pinned ACP v2 specification for its wire protocol.

acplause is experimental. Calendar versions identify releases; they do not promise compatibility. Breaking changes are highlighted in release notes.

Homebrew

brew install anesthetised/tap/acplause

The formula builds the tagged source on your machine, installing Go as a build dependency. On macOS, local compilation lets us distribute acplause without a paid Apple Developer ID certificate or an install hook that removes quarantine from downloaded binaries. The trade-off is a slower first install, including compilation of the SQLite dependency.

For a ready-to-run binary without installing Go, download the archive for your OS (macOS or Linux) and architecture (arm64 or amd64) from GitHub Releases. Extract it and put acplause in a directory on your PATH. Release archives include SHA256 checksums and GitHub artifact attestations. Prebuilt macOS binaries are not Developer ID signed or notarized, so macOS may require you to explicitly allow them to run.

go install github.com/anesthetised/acplause/cmd/acplause@latest

Configure

Configure your ACP v2 client to launch acplause with ACPLAUSE_API_KEY set to your provider key. The default provider is OpenRouter; set ACPLAUSE_BASE_URL for another OpenAI-compatible API root. Without a key, acplause sends no Authorization header, supporting compatible local providers.

Check setup from an environment with the same variables as the client:

acplause --version # version and source commit acplause doctor # local configuration and data-directory checks acplause doctor --online # also check the provider's model catalog

Select a model in the client before sending the first prompt. New sessions reuse your last model and reasoning effort; acplause never picks a substitute. See configuration, setup diagnostics and the usage guide.

Using acplause: models, Plan/Build, images, questions, plans and compaction.

Built-in tools: search, edits, permissions, terminals and project instructions.

MCP servers: stdio/HTTP setup, lifecycle and tool images.

Sessions and storage: resume, multiple windows and persistence.

All documentation: guides, architecture decisions and runtime verification.

ACP v2 is a draft. Actual T3 compatibility and known client gaps are recorded in the runtime smoke record.

just check # gofmt, vet, staticcheck, tests with -race, go mod tidy just e2e -v # end-to-end tests only

See development and testing and AGENTS.md.