amplifierd: The Amplifier daemon

amplifierd is a localhost HTTP daemon that exposes amplifier-core and amplifier-foundation capabilities over REST and SSE. It lets you drive Amplifier sessions from any language or framework that can make HTTP calls.

Under the hood, amplifierd is a thin HTTP layer on top of two libraries:

• amplifier-core — the agent runtime: sessions, LLM providers, tool execution, hooks, and the event system. amplifierd wires core events (content deltas, tool calls, approval requests) into its SSE transport and uses HookResult for tool-approval gates.
• amplifier-foundation — higher-level orchestration: bundle loading/preparation, child-session spawning, session forking, and working-directory management. amplifierd delegates bundle lifecycle to BundleRegistry and agent delegation to create_child_session.

amplifierd itself adds HTTP routing, the SessionManager/EventBus state layer, plugin discovery, and streaming transport — but all agent logic lives in the libraries.

Quick Start

Install amplifierd as a tool:

uv tool install git+https://github.com/microsoft/amplifierd
amplifierd serve

The daemon starts on http://127.0.0.1:8410. Verify with:

curl http://127.0.0.1:8410/health

Interactive API docs are at http://127.0.0.1:8410/docs (Swagger UI) or /redoc. The raw OpenAPI 3.1 schema is at /openapi.json.

Development setup

If you're working on amplifierd itself, use uv run from a local checkout:

cd amplifierd
uv sync --extra dev
uv run amplifierd serve

To run the test suite:

uv run pytest

Configuration

Settings resolve in priority order: CLI flags > environment variables > ~/.amplifierd/settings.json.

Setting	Env var	Default	Description
host	AMPLIFIERD_HOST	127.0.0.1	Bind address
port	AMPLIFIERD_PORT	8410	Bind port
log_level	AMPLIFIERD_LOG_LEVEL	info	Logging level
default_working_dir	AMPLIFIERD_DEFAULT_WORKING_DIR	None	Default CWD for new sessions
disabled_plugins	AMPLIFIERD_DISABLED_PLUGINS	[]	Plugin names to skip

CLI flags override everything:

amplifierd serve --host 0.0.0.0 --port 9000 --log-level debug

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Plugins

Plugins add custom endpoints to the daemon. See docs/plugins.md for the full guide on writing, installing, and configuring plugins.

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API Usage

See docs/api-usage.md for the full guide on driving amplifierd over HTTP and SSE, including usage patterns, a Python client wrapper, and the endpoint reference.