Projects worth a look
Not a star list but a selection with reasoning: harnesses, tool servers, measuring gear and curiosities - each with the paragraph explaining how it helps you build.
- Model Context Protocol - reference servers
Model Context Protocol - reference servers
modelcontextprotocol/servers View on GitHubThe gathering point for MCP servers: reference implementations plus a long list of servers from the community.
Why it is worth it90,568 starsTypeScriptUpdated Sep 2026Communityunratedtool-server · mcp · reference - OpenHands
A complete, open agent harness - the rare case where you can read the loop from the outside instead of guessing at it.
Why it is worth it89,007 starsTypeScriptUpdated Sep 2026Communityunratedharness · coding-agent · open-source - LiteLLM
A proxy that hides many providers behind a single OpenAI-compatible interface - and keeps count of what every call costs.
Why it is worth it59,511 starsPythonUpdated Sep 2026Community rating: 5.0 out of 5 from 1 ratinginference · proxy · provider - SWE-agent
SWE-agent
SWE-agent/SWE-agent View on GitHubThe research agent that solves real GitHub issues - and shows along the way how to measure agents in a comparable fashion at all.
Why it is worth it20,391 starsPythonUpdated Sep 2026Communityunratedeval · benchmark · research - Multica
A board where agents are entered as assignees - and the operational questions that start with the second agent, as readable Go code.
Why it is worth it51,247 starsGoUpdated Sep 2026Communityunratedorchestration · self-hosting