Efferent — composable agent SDK on Effect + Bun

Efferent separates service contracts, runtime composition, session lifecycle, and host presentation. See the framework guide for the plugin and configuration APIs.

Architecture

• core: shared schemas, ports and protocol helpers; no provider or host imports.
• runtime → core: plugin dependency graph and scoped plugin activation.
• sdk → runtime/core: Agent.define and Agent.turn, the composable agent over sessions.
• plugin-* → core: independently configurable capabilities, including the agent loop.
• evals: tasks, trials, graders and suites; evals-cli, evals-langfuse and evals-langsmith add the local CLI and exporters.
• foundry: independent verification framework, no internal package dependencies.

All production packages participate in the zero-baseline architecture gates. New session data uses .efferent/runtime; never delete old local data to reset it. Build artifacts go under .artifacts; external-consumer checks exercise the packed packages on Bun and Node without monorepo path aliases.