Module server 

Reusable building blocks for Rust-native MCP servers.

The mcp-server binary (in the sibling crates/mcp-server crate) is a complete generic MCP server: source navigation, GitHub access (issues + REST API with drill-down), workspace mode (github clone-and-track or local directory bind), watch mode, and manifest-driven Cypher / tool registration. Downstream crates that want the same framework with domain-specific tools layered on top depend on mcp-methods and call into the public modules below.

Typical layering pattern:

1. Construct server::ServerOptions from a manifest, optionally binding source roots, a default repo, or a workspace handle.
2. let mut server = server::McpServer::new(options);
3. Register your domain-specific tools with server::McpServer::register_typed_tool — typed arg struct plus a Fn(T) -> String handler. (For lower-level control, use server::McpServer::tool_router_mut and rmcp’s ToolRoute directly.)
4. server.serve(rmcp::transport::stdio()).await.

See kglite-mcp-server for a real example: it adds cypher_query, graph_overview, and save_graph tools that close over an active graph handle. Python authors running a FastMCP server can compose tools via the mcp_methods.fastmcp helper submodule (Python-side).

Note: the legacy embedder: / tools[].python: extension hooks that lived here in 0.3.25 have been removed. They required PyO3 in the framework’s source, which violated the pure-Rust constraint of this crate. Downstream Python-aware servers (kglite, etc.) implement their equivalent via a thin pyo3 wrapper in their own cdylib.

Re-exports

pub use manifest::find_sibling_manifest;

pub use manifest::find_workspace_manifest;

pub use manifest::load as load_manifest;

pub use manifest::BuiltinsConfig;

pub use manifest::EmbedderConfig;

pub use manifest::Manifest;

pub use manifest::ManifestError;

pub use manifest::PythonTool;

pub use manifest::SkillSource;

pub use manifest::SkillsSource;

pub use manifest::TempCleanup;

pub use manifest::ToolSpec;

pub use manifest::TrustConfig;

pub use manifest::WorkspaceConfig;

pub use manifest::WorkspaceKind;

pub use runtime::init_tracing;

pub use runtime::load_env_for_mode;

pub use runtime::maybe_watch;

pub use runtime::resolve_source_roots;

pub use server::serve_prompts;

pub use server::McpServer;

pub use server::RepoProvider;

pub use server::ServerOptions;

pub use skills::library_bundled_skills;

pub use skills::render_skill_template;

pub use skills::write_skill_template;

pub use skills::AppliesWhen;

pub use skills::BundledSkill;

pub use skills::GraphPropertyCheck;

pub use skills::PredicateClause;

pub use skills::PredicateOutcome;

pub use skills::Registry as SkillRegistry;

pub use skills::ResolvedRegistry;

pub use skills::Skill;

pub use skills::SkillActivation;

pub use skills::SkillError;

pub use skills::SkillFrontmatter;

pub use skills::SkillPredicateEvaluator;

pub use skills::SkillProvenance;

pub use source::SourceRootsProvider;

pub use watch::watch as watch_dir;

pub use watch::ChangeHandler;

pub use watch::WatchHandle;

pub use workspace::PostActivateHook;

pub use workspace::Workspace;

Modules

bundled_skills_index

Compile-time embedding of the framework’s bundled skills.

cli

Reusable helpers for skills-related CLI subcommands.

env

.env discovery + loader.

manifest

YAML manifest schema + loader.

runtime

Boot-time helpers shared by the framework binary and downstream domain binaries (e.g. kglite-mcp-server).

server

MCP ServerHandler implementation.

skills

Skills-aware MCP — runtime types, frontmatter parsing, three-layer resolution, and the Registry builder downstream binaries consume to wire skills into their MCP server.

source

Source-file tooling: read_source / grep / list_source.

watch

Filesystem-watcher subsystem for --watch DIR mode.

workspace

Workspace mode — two variants.