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

> Source: <https://github.com/anesthetised/acplause>
> Published: 2026-10-21 02:16:49+00:00

*Don't hold your acplause — it streams.*

acplause is an [Agent Client Protocol](https://agentclientprotocol.com) v2
agent. Your editor talks to it over stdio; it thinks with any
OpenAI-compatible Chat Completions API, [OpenRouter](https://openrouter.ai)
first, and works in your workspace through tools.

Inspired by [acp-bridge](https://github.com/BlakeHung/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.

- ACP v2 only, validated against the pinned schema (`testdata/schema/v2` ).
- Streaming text and reasoning, tool calls, usage and cost reporting.
- Live bash terminal output with bounded snapshots for session replay.
- Asks permission before changing files or running commands.
- Prompt queue, cancellation that aborts the HTTP stream and kills everything a command started, session list/resume/close/delete.
- Sessions survive restarts and can move between editor windows.
- Model and reasoning effort selection from OpenRouter's model list.
- PNG/JPEG prompt attachments and MCP tool images for models known to accept images.
- Session-owned MCP tools over stdio and Streamable HTTP.
- Structured user questions on clients advertising ACP form elicitation.
- Native ACP execution plans with persistent progress snapshots.
- Per-session Plan/Build modes with enforced tool restrictions.
- A discoverable `/compact` command to summarize older model context on demand.

```
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](https://github.com/anesthetised/acplause/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.

If you already have Go installed:

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

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](https://github.com/anesthetised/acplause/blob/main/docs/configuration.md), [setup diagnostics](https://github.com/anesthetised/acplause/blob/main/docs/troubleshooting.md)
and the [usage guide](https://github.com/anesthetised/acplause/blob/main/docs/usage.md).

- [Using acplause](https://github.com/anesthetised/acplause/blob/main/docs/usage.md) : models, Plan/Build, images, questions, plans and compaction.
- [Built-in tools](https://github.com/anesthetised/acplause/blob/main/docs/tools.md) : search, edits, permissions, terminals and project instructions.
- [MCP servers](https://github.com/anesthetised/acplause/blob/main/docs/mcp.md) : stdio/HTTP setup, lifecycle and tool images.
- [Sessions and storage](https://github.com/anesthetised/acplause/blob/main/docs/sessions.md) : resume, multiple windows and persistence.
- [All documentation](https://github.com/anesthetised/acplause/blob/main/docs/README.md) : 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](https://github.com/anesthetised/acplause/blob/main/docs/testing/t3-first-class-smoke.md).

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

See [development and testing](https://github.com/anesthetised/acplause/blob/main/docs/development.md) and [AGENTS.md](https://github.com/anesthetised/acplause/blob/main/AGENTS.md).