5f46fec5ad
The runtime already framed JSON-RPC initialize traffic over stdio, so this extends the same transport with typed helpers for tools/list, tools/call, resources/list, and resources/read plus fake-server tests that exercise real request/response roundtrips. Constraint: Must build on the existing stdio JSON-RPC framing rather than introducing a separate MCP client layer Rejected: Leave method payloads as untyped serde_json::Value blobs | weakens call sites and test assertions Confidence: high Scope-risk: narrow Reversibility: clean Directive: Keep new MCP stdio methods aligned with upstream MCP camelCase field names when adding more request/response types Tested: cargo fmt --manifest-path rust/Cargo.toml --all; cargo clippy --manifest-path rust/Cargo.toml -p runtime --all-targets -- -D warnings; cargo test --manifest-path rust/Cargo.toml -p runtime Not-tested: Live integration against external MCP servers
Rust port foundation
This directory contains the first compatibility-first Rust foundation for a drop-in Claude Code CLI replacement.
Current milestone
This initial milestone focuses on harness-first scaffolding, not full feature parity:
- a Cargo workspace aligned to major upstream seams
- a placeholder CLI crate (
rusty-claude-cli) - runtime, command, and tool registry skeleton crates
- a
compat-harnesscrate that reads the upstream TypeScript sources in../src/ - tests that prove upstream manifests/bootstrap hints can be extracted from the leaked TypeScript codebase
Workspace layout
rust/
├── Cargo.toml
├── README.md
├── crates/
│ ├── rusty-claude-cli/
│ ├── runtime/
│ ├── commands/
│ ├── tools/
│ └── compat-harness/
└── tests/
How to use
From this directory:
cargo fmt --all
cargo check --workspace
cargo test --workspace
cargo run -p rusty-claude-cli -- --help
cargo run -p rusty-claude-cli -- dump-manifests
cargo run -p rusty-claude-cli -- bootstrap-plan
Design notes
The shape follows the PRD's harness-first recommendation:
- Extract observable upstream command/tool/bootstrap facts first.
- Keep Rust module boundaries recognizable.
- Grow runtime compatibility behind proof artifacts.
- Document explicit gaps instead of implying drop-in parity too early.
Relationship to the root README
The repository root README explains the leaked TypeScript codebase. This document tracks the Rust replacement effort that lives in rust/.