Concepts
Concepts
Six contracts. Every AgentsKit package is an implementation of one of them.
AgentsKit has six stable contracts. Every package — every provider, every memory backend, every tool, every UI binding — plugs into one of them. Learn the shape once; swap implementations forever.
The six contracts
| Contract | What it abstracts | Page |
|---|---|---|
| Adapter | LLM providers | adapter |
| Tool | callable functions | tool |
| Skill | personas + prompts | skill |
| Memory | conversation + vector state | memory |
| Retriever | context retrieval | retriever |
| Runtime | the orchestration loop | runtime |
Start here
- Mental model — how the six contracts compose.
- Implementations — every concrete implementation per contract.
- Errors — the error taxonomy every contract honors.
See also
- Packages overview — packages grouped by role.
- For agents — dense LLM-friendly reference per contract.
- Comparison — AgentsKit vs LangChain / Vercel AI / Mastra.