4d79997120
The License section named MIT. LICENSE is a transition file: new code contributions are Apache-2.0, documentation excluding specifications is CC-BY-4.0, and only earlier contributions without relicensing consent stay MIT. "Rust (stable)" understates the floor. rmcp, darling and time declare rust-version 1.88, and cargo metadata resolves both crates to 1.88. The Ruby aside said 3.3 also satisfies the gems. anthropic requires >= 3.2.0 and mcp >= 2.7.0, so the gem floor was 3.2, and 3.2 reached EOL on 2026-03-31. CI runs 3.4, which is what the READMEs now state. The Go and Rust clients take a command plus arguments, not a path to a server script. Removed the commit-message convention, which is attributed to the MCP contributing guidelines but does not appear in them. Added the AI_POLICY.md link that CONTRIBUTING.md points to. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GdvHa5MzDw33PEz3DbTaJD
38 lines
1.7 KiB
Markdown
38 lines
1.7 KiB
Markdown
# An LLM-Powered Chatbot MCP Client written in Rust
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An interactive chatbot MCP client: it launches an MCP server over stdio, lists its tools, and hands them to Claude, which can call them while answering your questions.
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This example accompanies the [Build an MCP client](https://modelcontextprotocol.io/docs/develop/build-client) tutorial.
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## Prerequisites
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- Rust 1.88+ and Cargo
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- An [Anthropic API key](https://console.anthropic.com/) (optional — see below)
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## Setup
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Export your API key, or put it in a `.env` file in this directory (the `.env` file is optional):
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```bash
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export ANTHROPIC_API_KEY=your-api-key-here
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```
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## Run the client
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Pass the command that starts the server — a binary or a script — after `--`:
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```bash
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cargo run -- ../weather-server-rust/target/release/weather
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```
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(Build the server first with `cargo build --release` in its directory.)
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Type a question (for example, "What's the weather in Sacramento?") and Claude answers using the server's tools. Type `quit` to exit.
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Without an `ANTHROPIC_API_KEY`, the client still connects, prints the server's tools, and exits — useful for verifying the MCP wiring without credentials.
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## Structured content
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rmcp does not validate tool output, so this client compiles each declared `outputSchema` at connect time and checks results against it — the spec's client-side SHOULD. It uses the [`jsonschema`](https://docs.rs/jsonschema) crate, which rmcp's own documentation recommends.
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The two channels go to different readers: `content` is forwarded to the model, while `structured_content` is used as data — the client counts the items it returns. See [Structured Content](https://modelcontextprotocol.io/specification/2026-07-28/server/tools#structured-content).
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