Epistates/TurboMCP

[3.0.12] - 2026-04-13

Added

• Draft extensions capability — Both ClientCapabilities and ServerCapabilities now carry an optional extensions: HashMap<String, Value> map for opt-in key/value capability settings, available across turbomcp-types, turbomcp-core, and turbomcp-protocol. New builder helpers (with_extensions, add_extension) plus a completions server capability round out the stable 2025-11-25 shape. CapabilityMatcher treats extensions as mutually opt-in: negotiation requires both sides to declare an extension and silently disables mismatches rather than failing the session.

• Handler-driven initialize response — New McpHandler::server_capabilities() trait method with a default that derives tools/resources/prompts from existing listings, letting handlers override to advertise tasks, logging, completions, or draft extensions without forking the router. build_initialize_result now serializes the handler's full ServerCapabilities and ServerInfo via serde_json::to_value, so description, title, websiteUrl, and icons survive the initialize response instead of being silently dropped.

• Client::initialize_with_request() — New entry point that accepts a caller-built InitializeRequest, giving applications a stable way to opt into draft protocol versions or explicit capability shapes. The ergonomic Client::initialize() default path and auto-connect logic now share the same implementation.

• RequiredCapabilities / ClientCapabilities extensions field (turbomcp-server::config) — New extensions: HashSet<String> field with builder, validation, and from_params parsing, letting deployments require specific draft extensions from clients.

• MCP 2025-11-25 icons plural migration in turbomcp-core (SEP-973) — Replaces icon: Option<Icon> with icons: Option<Vec<Icon>> on Implementation, Tool, Resource, ResourceTemplate, and Prompt. Adds description and website_url to Implementation with builder helpers. turbomcp-types and turbomcp-protocol already carried the plural shape; this catches turbomcp-core's parallel types and every literal constructor across turbomcp-grpc and turbomcp-wasm up to the spec.

• gRPC capability + metadata parity — mcp.proto gains EmptyCapability, elicitation, client/server task capability trees, CompletionCapability, and ExtensionsCapabilities messages, wired into ClientCapabilities and ServerCapabilities. repeated Icon icons replaces singular icon on Implementation, Tool, Resource, ResourceTemplate, and Prompt, with new title, description, website_url, and size fields per spec. convert.rs bidirectional conversions preserve extensions, elicitation, tasks, completions, and experimental capabilities via new encode_json_map / decode_json_map / empty_capability_from_map helpers, covered by round-trip tests for Implementation metadata and extensions + task tools.

Changed

• Version adapters strip draft extensions — V2025_11_25Adapter and V2025_06_18Adapter now strip the draft extensions field from filter_capabilities and from initialize results; DraftAdapter passes it through. Regression tests cover both stripping and draft passthrough.

Fixed

• wasm-server feature compiles again — The wasm-server-gated files turbomcp-wasm/src/wasm_server/server.rs and composite.rs carried two latent build breaks introduced during the icons + extensions work (they are skipped by default cargo check --workspace --all-targets). Removes spurious website_url: None from eight Tool/Resource/ResourceTemplate/Prompt literals (only Implementation carries website_url), and adds completions: None + extensions: None to the two ServerCapabilities constructors to match the new core shape. Verified with cargo check, cargo clippy -- -D warnings, and cargo test --lib -p turbomcp-wasm --features wasm-server (119 tests passing).

• Stdio backend spawn tests no longer depend on Python (turbomcp-proxy) — Tests hardcoded python server.py / python -c '...', which fail on systems where only python3 is on PATH (current macOS default) and race because python -c exits before wait_for_ready can observe a running child. Replaced with /bin/cat, gated #[cfg(unix)] since Windows handles subprocess spawning differently.

• Workspace internal dep versions unified at 3.0.11 — turbomcp-macros, turbomcp-proxy, turbomcp-server, and turbomcp-telemetry still pinned internal deps to the stale 3.0.7 version while the rest of the tree had moved on. Switched to workspace = true so they inherit the workspace-declared version in one place; turbomcp's remaining explicit path deps (which must keep default-features = false) bumped to match.

Full Changelog: https://github.com/Epistates/turbomcp/compare/v3.0.11...v3.0.12