175 listed
Harnesses & SDKs
Frameworks and SDKs for building agents: the Claude Agent SDK, OpenAI Agents SDK, LangGraph, CrewAI and many more. Each page lists languages, packages, MCP and A2A support and how it orchestrates agents, with a link to the page every fact came from.
Showing 1–24 of 47
- 0.867score
Pi Agent Core
Earendil
Minimal TypeScript agent harness with an agent runtime, multi-provider LLM API, terminal UI and coding agent CLI that users extend themselves.
HarnessAFreshness: A★ 117.6K↓ 5.1M/wk - 0.851score
Strands Agents
AWS
Open-source Python and TypeScript SDK for model-driven agents, with tools, MCP, multi-agent patterns and streaming.
HarnessAFreshness: A★ 8.9K↓ 8.9M/wk - 0.841score
GitHub Copilot SDK
GitHub
Multi-language SDKs for embedding the GitHub Copilot agent runtime, with planning, tool calls and file edits, in your apps.
HarnessAFreshness: A★ 10.6K↓ 1.2M/wk - 0.831score
CopilotKit
CopilotKit
Open-source SDK that connects AI agents to app front ends with chat UI, generative UI, shared state and human approvals; creator of the AG-UI protocol.
HarnessAFreshness: A★ 38.2K↓ 286.2K/wk - 0.799score
Genkit
Google
Open-source Firebase framework for AI features and agent workflows in JavaScript, Go, Python and Dart, with model plugins.
HarnessAFreshness: A★ 6.5K↓ 95.8K/wk - 0.799score
Letta
Letta
Open-source agent harness for stateful agents whose memory persists and improves with use, with a terminal UI, app server and TypeScript SDK.
HarnessAFreshness: A★ 25.2K↓ 40.7K/wk - 0.787score
trueforge
truefoundry
Open-source agent harness that runs the model loop for you, with MCP tools, skills, sandboxing, approvals and a chat UI.
HarnessAFreshness: A★ 6.4K - 0.777score
ADK for TypeScript
Google
TypeScript toolkit for agents with Zod-typed tools, graph and multi-agent workflows, and Node.js or browser runtimes.
HarnessAFreshness: A★ 1.4K↓ 143.5K/wk - 0.771score
Ax
Ax
DSPy-style toolkit for typed LLM signatures, agents and flows, TypeScript-first with Python, Java, C++, Go and Rust libraries.
HarnessAFreshness: A★ 3K↓ 27.2K/wk - 0.756score
ai
TanStack
TypeScript SDK for streaming chat, tool-calling agents and structured output across model providers and UI frameworks.
HarnessAFreshness: A★ 3.2K - 0.745score
BeeAI Framework
IBM / Linux Foundation
Python and TypeScript framework for multi-agent systems, with MCP and A2A interop, YAML orchestration and OpenTelemetry tracing.
HarnessAFreshness: A★ 3.4K↓ 5.4K/wk - 0.740score
Deep Agents
LangChain
Opinionated agent harness on LangGraph with sub-agents, filesystem access, context management, persistent memory and approval of tool calls.
HarnessAFreshness: A★ 30.6K↓ 1.9M/wk - 0.737score
Mastra
Mastra
TypeScript framework for AI agents and apps with graph-based workflows, memory, suspend-and-resume approvals, MCP servers and model routing.
HarnessAFreshness: A★ 29.1K↓ 1.4M/wk - 0.734score
Google Agent Development Kit (ADK)
Google
Open-source toolkit for building, evaluating and deploying agents in Python, TypeScript, Go, Java and Kotlin, tuned for Gemini but model-agnostic.
HarnessAFreshness: A★ 22K↓ 2.4M/wk - 0.731score
stagehand
browserbase
SDK for browser agents with act, observe and extract calls, used from TypeScript and Python to automate sites and pull out structured data.
HarnessAFreshness: A★ 25.8K↓ 996K/wk - 0.729score
Agent Squad
2FastLabs
Open-source framework that routes each user query to one of several AI agents, with Python, TypeScript and Swift runtimes.
HarnessAFreshness: A★ 7.8K↓ 1.5K/wk - 0.727score
Vercel AI SDK
Vercel
TypeScript toolkit for AI apps and agents with a unified provider API, streaming, UI hooks and a wrapper for running established agent harnesses.
HarnessAFreshness: A★ 27.5K - 0.717score
LangGraph.js
LangChain
Open-source agent harness from LangChain for building agents with code, with LangSmith for testing and monitoring.
HarnessAFreshness: A★ 3.4K↓ 2.3M/wk - 0.714score
LangChain.js
LangChain
JavaScript and TypeScript framework of interoperable components for building LLM apps and agents, with LangGraph.js and Deep Agents above it.
HarnessAFreshness: A★ 18.3K - 0.713score
Claude Agent SDK (TypeScript)
Anthropic
TypeScript SDK that gives programs Claude Code's built-in tools for reading, editing and running code, installed from npm.
HarnessAFreshness: A★ 1.8K↓ 8.1M/wk - 0.710score
trigger.dev
triggerdotdev
TypeScript platform to build and deploy long-running AI agents and workflows with retries, queues and human approval steps.
HarnessAFreshness: A★ 16.6K - 0.699score
VoltAgent
VoltAgent
TypeScript framework for AI agents with tools, memory, RAG, MCP and sub-agents, paired with a Cloud or self-hosted console.
HarnessAFreshness: A★ 10.9K - 0.695score
notte
nottelabs
Browser infrastructure for AI agents: local and cloud Playwright-based browser sessions, scraping and deployable browser functions.
HarnessAFreshness: A★ 2K↓ 602/wk - 0.688score
metorial
metorial
Open-source access layer that connects AI agents to 1200+ integrations with shared auth, permissions and audit logs.
HarnessAFreshness: A★ 3.4K↓ 236/wk