Alternatives to Harness Sdk

Open-source AI SDK and toolkit for building agentic apps and agents in TypeScript, Go, Python, and Dart.

SmolAgents is Hugging Face's open-source Python library for building code-writing AI agents in a few lines of code.

Microsoft's open-source, code-first Python framework for building stateful, data-intensive conversational AI agents.

A free, MIT-licensed Python framework from OpenAI for building multi-agent workflows with handoffs, guardrails, and tracing.

Mastra is an open-source TypeScript agent framework for durable agents, typed workflows, and built-in evals.

Open-source TypeScript AI SDK for streaming AI apps and agents across 100+ models with built-in fallbacks

Microsoft's open-source SDK for building AI agents and copilots with plugins, memory, and multi-agent orchestration.

Guidance is an open-source Python library for constrained LLM generation with regex, context-free grammars, and inline control flow.

BAML is a type-safe, Turing-complete language for agentic and LLM code that compiles typed Python and TypeScript SDKs.

Eino is an open-source Go LLM framework from ByteDance for building agents, graphs, and RAG pipelines in your existing Go backend.

Open-source Rust library for building streaming, parallel LLM pipelines — data indexing, retrieval-augmented generation, and autonomous agents.

Open Harness is an MIT-licensed TypeScript SDK for building Claude Code-style agents with stateless primitives and composable middleware.

Mirascope is an open-source Python library that turns LLM calls, tools, and prompt versioning into plain decorated functions.

Open-source multi-agent framework that assigns PM, architect, engineer and QA roles to LLMs for structured software tasks

Open-source React framework for agent chat, generative UI, and shared state on any AG-UI backend.

Microsoft's MIT-licensed Python and .NET framework for building conversational and event-driven multi-agent AI applications.

Haystack is deepset's open-source Python framework for building inspectable RAG pipelines and production-grade AI agents.

Open-source, self-hosted agentic data assistant that connects to your databases, writes SQL and code, and runs analysis in sandboxes

Hermes Desktop is a free, open-source desktop GUI for the Hermes Agent — a self-hosted AI agent with a built-in learning loop that turns

Hermes Agent is an open-source, self-hosted AI agent with persistent memory that auto-builds reusable skills and reaches you on 20+ chat

OpenAI Cookbook delivers free, MIT-licensed Python notebooks and guides for building with the OpenAI API.

Open-source, self-hosted AI agent that plans tasks, runs tools, and grows its own long-term memory.

DeerFlow is an open-source SuperAgent harness that researches, codes, and creates inside a persistent Docker sandbox.

Open-source AI agent loop that iterates a task list in Docker Sandboxes and commits the results.

Open-source library of 817 structured cybersecurity skill files your AI coding agent loads on demand, mapped to MITRE ATT&CK and licensed Apache 2.0.

Open-source LLM from UC Berkeley that turns natural language into API calls and tool-using agent actions.

UmaDev is an open-source Rust CLI that turns your logged-in local coding agents into an eight-role AI dev team with governance gates and

Open-source meta-harness for running Claude Code, Codex, Pi and custom AI coding agents under one policy and sandbox

Foreman is an open-source Textual TUI that orchestrates headless Claude Code agents through a gated plan → ADR/PRD → issues → TDD → e2e

ECC is an open-source agent harness operating layer that gives Claude Code, Codex, Cursor, OpenCode and Kimi shared skills, memory,