Using Ultimo with AI coding agents
Ultimo is built to be easy for coding agents to build with — Cursor, Claude Code, GitHub Copilot, and friends. This page shows how to point your agent at Ultimo's machine-readable docs, drop in a project ruleset, and (soon) connect the Ultimo MCP server.
Why Ultimo is agent-friendly
- Typed contracts, generated clients. You write your API once in Rust
(
RpcRegistry), and the TypeScript client — types and all — is generated from it. The agent never hand-writes or guesses client types; they're derived. See TypeScript Clients and the RPC System. - Scaffolds that build.
ultimo newproduces projects that compile out of the box, with dependency pins that track the current release — no stale-version dead ends. - One obvious way. Convention-over-config and opt-in Cargo features mean fewer choices for an agent to get wrong.
1. Point your agent at the docs
Ultimo's docs are published in the machine-readable llms.txt format, which agents fetch to ground themselves in the current API instead of stale training data:
- Index:
https://docs.ultimo.dev/llms.txt— every page with a one-line summary. - Full corpus:
https://docs.ultimo.dev/llms-full.txt— the complete docs in one file.
Most agents pick these up automatically when you add the docs site as a
documentation source. In Cursor, add https://docs.ultimo.dev under
Settings → Indexing → Docs; in Claude Code, reference the URL in your prompt
or CLAUDE.md.
2. Use Context7
Ultimo is indexed on Context7, which
serves version-accurate snippets to agents on demand. If your agent supports the
Context7 MCP server, it can pull Ultimo examples mid-task. Point it at the library
id ultimo-rs/ultimo.
3. Add a project ruleset
Every project scaffolded with ultimo new includes an AGENTS.md — working
notes that orient an agent to that project's conventions (how to add a route or
RPC procedure, the feature flags, the run/test/generate commands). It follows the
AGENTS.md open standard, which Cursor, Claude Code, and
others read automatically.
If you started from an existing project, drop an AGENTS.md at its root with the
same content — see the scaffolded file for a template.
4. The Ultimo MCP server (coming soon)
An ultimo mcp server is in development. It will give your agent live, typed
tools instead of guesswork — searching the docs, listing runnable examples,
scaffolding projects, and introspecting your project's RPC surface (so the
agent can ask "what's my typed API?" and get an exact answer). Tracked on the
roadmap; this page will document the setup when it ships.
Prompting tips
- Ask the agent to regenerate the client (
ultimo generate -o ./client.ts) after changing any RPC type — the generated client is the source of truth for the frontend. - Handlers return
Result<Response>; nudge the agent to returnErr(UltimoError::…)for error cases rather than panicking. - Point it at the specific docs page for the feature it's using (e.g. Authentication, Sessions, WebSocket, SSE) — each page's examples are self-contained and compile.