Hatchet: An Orchestration Engine for AI Agents and Persistent Workflows

Hatchet is an open-source orchestration engine designed for background tasks, AI agents, and persistent workflows. It provides reliable task scheduling, state management, and fault tolerance mechanisms to support building complex asynchronous application systems. Key focus areas include addressing the unique needs of AI agents and ensuring workflow persistence even in case of failures.

Modern applications increasingly rely on async processing, but it brings complexities: state management difficulties, error handling complexity, debugging challenges, and ensuring exactly-once semantics. Traditional task queues (Celery, RabbitMQ) solve basic distribution but struggle with complex workflows, especially for AI agents (multi-step reasoning, tool calls, long LLM runs).

Hatchet's core features include:

• Persistent Workflows: State is stored persistently, enabling recovery from service restarts/failures (critical for long AI workflows).
• Reliable Execution Semantics: Options like at-least-once, at-most-once, exactly-once (tailored to task type, e.g., exactly-once for payments).
• Observability: Built-in visualization of workflow state/progress, plus metrics/logs for monitoring.
• Multi-Language SDK: Support for TypeScript, Python, Go with type-safe APIs.

Hatchet is optimized for AI agents:

• LLM Call Handling: Supports async, streaming responses, timeout management, and graceful degradation for long LLM runs.
• Tool Calls: Models tool interactions (search, DB, APIs) as workflow steps with retry/error handling.
• Human Collaboration: Pauses workflows for manual input (e.g., content审核) and resumes automatically.

Hatchet uses a cloud-native architecture with scheduler (task coordination), executor (task execution), and state storage components. Deployment modes:

• Dev: In-memory storage for small-scale use.
• Production: PostgreSQL (state) + Redis (message broker).
• Managed Cloud Service: For teams focusing on business logic.

Hatchet differentiates from competitors:

• vs Temporal: Lighter and easier to use (lower learning curve) while maintaining core reliability.
• vs Airflow: Focuses on application workflows (not data ETL) with modern programming models.
• vs LangChain Agent: Provides general orchestration infrastructure to complement LangChain's agent logic.

Hatchet is suitable for:

• E-commerce Order Processing: Orchestrates steps like payment confirmation, inventory deduction, logistics notifications.
• Content审核 Pipeline: Combines auto detection, manual review, and feedback loops.
• AI Data Analysis: Manages data extraction, multi-round LLM analysis, result validation, and report generation.

Hatchet addresses the growing need for reliable workflow orchestration in AI and async applications. It's open-source with active development, detailed docs, and a GitHub community. Teams building AI agents or complex async systems should consider Hatchet for its persistence, AI support, and ease of use.