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 new produces 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

The CLI ships a Model Context Protocol server that gives your agent live, typed tools instead of guesswork. Install the CLI (cargo install ultimo-cli) and register the server with your agent:

{
  "mcpServers": {
    "ultimo": { "command": "ultimo", "args": ["mcp"] }
  }
}

(In Claude Code: claude mcp add ultimo -- ultimo mcp. In Cursor: add the block above to ~/.cursor/mcp.json.)

The server exposes these tools:

Tool	What it does
`search_docs`	Search the current Ultimo docs and return the most relevant sections.
`get_doc`	Return a named docs page in full.
`list_examples` / `get_example`	List runnable examples and read their source.
`scaffold`	Create a new Ultimo project from a template (`basic`/`rpc`/…).
`introspect_rpc`	Build a project's `RpcRegistry` and return its generated typed client + procedure list — the agent asks "what's my typed API?" and gets an exact answer.

The docs tools stay current by reading the live llms.txt corpus, so the agent is grounded in the deployed API rather than stale memory.

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 return Err(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.