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Components & architecture

antcrew is made of four independent pieces. Each can run without the others, but together they give you end-to-end observability and control over your AI pipelines.

antcrew — the agent framework

antcrew is the Python package your team builds and ships agent logic with.

What it does:

  • Provides ready-made agent roles — PM, developer, reviewer, QA — built on LangGraph
  • Ships a CLI (antcrew run …) to execute pipelines locally or in CI
  • Integrates with Slack, Telegram, and other notification channels
  • Depends on antcrew-engine for all LLM calls, tracing, and HITL logic

What it is not: a server or a UI. It's a library you install in your project.

pip install antcrew

antcrew-engine — the core SDK

antcrew-engine is the low-level Python library that the framework builds on. You can also use it directly without the full agent framework.

What it does:

  • Turns Python functions into LLM prompts via @contract — the docstring becomes the system prompt, the type annotations enforce the output schema
  • Runs every LLM call through a configurable provider (openai:gpt-4o, anthropic:claude-opus-5, simulated:echo for tests…)
  • Writes every token, tool call, and intermediate result to a TraceLog — a structured, append-only record of the full run
  • Exposes hitl_checkpoint() — a blocking call that pauses agent execution and waits for a human to approve before continuing

What it is not: a server, a database, or a UI. It's a library.

pip install antcrew-engine

antcrew-platform — the cloud control plane

antcrew-platform is the managed web application running at antcrew.org.

What it does:

  • Receives runs from the engine via POST /runs
  • Stores every event — status changes, TraceLog events, tickets created — and serves them over a real-time WebSocket
  • Serves the dashboard so your team can watch runs live, review HITL queues, and inspect tickets
  • Manages HITL review queues — reviewers see pending approvals and can approve, reject, or comment
  • Extracts structured tickets from run output with workspace-scoped display IDs (PROJ-00001)
  • Sends outbound webhooks to your own systems when runs complete or reviews are needed

What it is not: it never executes your agent code. It is an observer and gating layer, not a worker.

antcrew-proxy — the LLM gateway

antcrew-proxy is an OpenAI-compatible HTTP proxy.

What it does:

  • Accepts model calls from the engine using the standard POST /v1/chat/completions interface
  • Looks up the caller's workspace in the platform and injects the right provider API key (BYOK)
  • Routes to the correct upstream provider based on the model prefix in the request (openai:, anthropic:, groq:, gemini:…)
  • Your application code never handles LLM credentials directly

What it is not: required. You can use the engine without the proxy by setting provider keys directly on the Agent. The proxy is valuable when you have multiple workspaces with different LLM budgets or key rotation requirements.

How a run flows through the system

sequenceDiagram
    autonumber
    participant Code as Your agent code<br/>(antcrew / antcrew-engine)
    participant Proxy as antcrew-proxy
    participant LLM as LLM provider
    participant Platform as antcrew-platform
    participant Human as Human reviewer

    Code->>Platform: POST /runs — start a new run
    Platform-->>Code: run_id

    Code->>Proxy: POST /v1/chat/completions (model call)
    Proxy->>LLM: forward with injected API key
    LLM-->>Proxy: completion
    Proxy-->>Code: response

    Code->>Platform: POST /runs/{id}/events — TraceLog entry

    Note over Code,Platform: hitl_checkpoint() reached

    Code->>Platform: POST /reviews — pending review
    Platform->>Human: notify (webhook / email)
    Human->>Platform: approve
    Platform-->>Code: resume signal

    Code->>Platform: POST /runs/{id}/events — TraceLog (run complete)

Component overview

Component Role Where it runs
antcrew Agent framework + CLI Your codebase
antcrew-engine LLM calls, contracts, TraceLog, HITL Your codebase
antcrew-platform Dashboard, storage, HITL reviews antcrew.org (managed cloud)
antcrew-proxy LLM routing, BYOK key injection antcrew.org or your own infra