AGENTS.md
agentsmd/agents.md
The open standard for agent instructions in repositories.
AGENTS.md is the open format for repo-scoped agent briefings: nested files scope instructions per directory so agents get a map of what exists and load only what's relevant. Read by 20+ tools including Codex, Cursor and Copilot — context engineering as a convention.
Related projects
Anthropic Skills
anthropics/skills
The official Agent Skills repository.
Anthropic's official Agent Skills: SKILL.md-based folders (instructions, scripts, resources) that Claude dynamically loads in Claude Code, Claude.ai and the API. The reference implementation for progressive-disclosure skill packs.
Composio
ComposioHQ/composio
Integration layer and toolset for AI agents.
Composio provides 250+ managed, authenticated integrations (GitHub, Slack, CRMs, browsers…) exposed as agent tools, with observability and access control — 'auth + integrations as a service' for the harness layer.
OpenAI Agents SDK
openai/openai-agents-python
A lightweight, production-ready multi-agent SDK with tracing.
The successor to the Swarm experiments: a primitives-based SDK (agents, handoffs, guardrails, sessions) with built-in tracing and MCP support. OpenAI's main contribution to the orchestration layer.