feat(serve): add multi-graph support to MCP server (#581)

.gitignore

@@ -14,6 +14,7 @@ build/
 *.egg
 .graphify/
 graphify-out/
+.worktrees/
 .graphify_*.json
 .graphify_python
 .claude/

Dockerfile

@@ -1,25 +1,15 @@
-# graphify MCP server as a shared HTTP service (issue #1143).
-#
-# Build:  docker build -t graphify .
-# Run:    docker run -p 8080:8080 -v "$(pwd)/graphify-out:/data" graphify \
-#             /data/graph.json --transport http --host 0.0.0.0 --api-key "$SECRET"
-#
-# Builds from source so the image includes the Streamable HTTP transport even
-# before it lands on PyPI. The graph.json is mounted at runtime (-v), never
-# baked into the image.
+# graphify MCP server. Mount a repository containing graphify-out/graph.json.
 FROM python:3.12-slim
-
 WORKDIR /app
 COPY . /app
 
 # The [mcp] extra pulls mcp + starlette + uvicorn, which the HTTP transport needs.
 RUN pip install --no-cache-dir ".[mcp]"
 
-# Run as a non-root user — the server is network-exposed.
+# Run as a non-root user because the server is network-exposed.
 RUN useradd --create-home --uid 10001 graphify
 USER graphify
 
 EXPOSE 8080
-
-ENTRYPOINT ["python", "-m", "graphify.serve"]
-CMD ["/data/graph.json", "--transport", "http", "--host", "0.0.0.0", "--port", "8080"]
+ENTRYPOINT ["graphify"]
+CMD ["/data", "--mcp", "--transport", "http", "--host", "0.0.0.0", "--port", "8080"]

README.md

@@ -485,15 +485,28 @@ The default `127.0.0.1` bind is loopback-only. Set `--host 0.0.0.0` **and** `--a
 
 ```bash
 docker build -t graphify .
-docker run -p 8080:8080 -v "$(pwd)/graphify-out:/data" graphify \
-  /data/graph.json --transport http --host 0.0.0.0 --api-key "$SECRET"
+docker run -p 8080:8080 -v "$(pwd):/data:ro" graphify /data --mcp --transport http --host 0.0.0.0 --api-key "$SECRET"
 ```
 
 > **WSL / Linux note:** Ubuntu ships `python3`, not `python`. Use a venv to avoid conflicts:
 > ```bash
 > python3 -m venv .venv && .venv/bin/pip install "graphifyy[mcp]"
 > ```
 
+### Multi-graph MCP server
+
+Serve multiple repositories containing `graphify-out/graph.json` from one MCP endpoint. This is useful for multi-repo setups, monorepos with per-service graphs, or comparing codebases.
+
+```bash
+# Serve over stdio (the default transport).
+graphify ../frontend ../backend --mcp
+
+# Serve over HTTP. Remote HTTP requires a nonblank API key.
+graphify ../frontend ../backend --mcp --transport http --host 0.0.0.0 --port 8080 --api-key "$SECRET"
+```
+
+Tools: same as single-graph (`query_graph`, `get_node`, `get_neighbors`, etc.) plus `list_graphs` and `use_graph`. Each tool accepts an optional `graph` parameter to target a specific graph, or use `use_graph` to set a session default.
+
 ---
 
 ## Environment variables

graphify/__main__.py

@@ -479,6 +479,132 @@ def main() -> None:
             raise
 
 
+def _start_mcp_registry(registry) -> None:
+    from graphify.serve import serve
+
+    serve(registry=registry)
+
+
+def _serve_mcp_repositories(
+    paths: list[str],
+    *,
+    transport: str,
+    host: str = "127.0.0.1",
+    port: int = 8080,
+    api_key: str | None = None,
+) -> None:
+    from graphify.serve import GraphRegistry
+
+    if not paths:
+        print("error: --mcp requires at least one repository path", file=sys.stderr)
+        raise SystemExit(1)
+    resolved = [Path(path).resolve() for path in paths]
+    names = [path.name for path in resolved]
+    duplicate = next((name for name in names if names.count(name) > 1), None)
+    if duplicate is not None:
+        print(f"error: duplicate graph name {duplicate!r}; repository basenames must be unique", file=sys.stderr)
+        raise SystemExit(1)
+    graph_paths = []
+    for repo in resolved:
+        graph_path = repo / _GRAPHIFY_OUT / "graph.json"
+        try:
+            exists = graph_path.is_file()
+        except OSError as exc:
+            print(f"error: could not read graph: {graph_path} ({exc})", file=sys.stderr)
+            raise SystemExit(1) from None
+        if not exists:
+            print(f"error: graph not found: {graph_path}", file=sys.stderr)
+            raise SystemExit(1)
+        graph_paths.append(graph_path)
+    try:
+        registry = GraphRegistry.from_paths(graph_paths)
+    except OSError as exc:
+        print(f"error: could not read graph: {exc}", file=sys.stderr)
+        raise SystemExit(1) from None
+    if transport == "http":
+        from graphify.serve import serve_http
+
+        serve_http(registry=registry, host=host, port=port, api_key=api_key)
+    else:
+        _start_mcp_registry(registry)
+
+
+def _run_mcp_cli(args: list[str]) -> bool:
+    if "--mcp" not in args:
+        return False
+
+    paths: list[str] = []
+    transport = "stdio"
+    host = "127.0.0.1"
+    port = 8080
+    api_key = os.environ.get("GRAPHIFY_API_KEY")
+    index = 0
+    while index < len(args):
+        arg = args[index]
+        if arg == "--mcp":
+            index += 1
+        elif arg == "--transport":
+            index += 1
+            if index == len(args) or args[index] not in {"stdio", "http"}:
+                print("error: --transport must be stdio or http", file=sys.stderr)
+                raise SystemExit(1)
+            transport = args[index]
+            index += 1
+        elif arg == "--host":
+            index += 1
+            if index == len(args):
+                print("error: --host requires a value", file=sys.stderr)
+                raise SystemExit(1)
+            if args[index].startswith("-"):
+                print(f"error: unrecognized MCP option: {args[index]}", file=sys.stderr)
+                raise SystemExit(1)
+            host = args[index]
+            index += 1
+        elif arg == "--port":
+            index += 1
+            if index == len(args):
+                print("error: --port requires an integer", file=sys.stderr)
+                raise SystemExit(1)
+            try:
+                port = int(args[index])
+            except ValueError:
+                print("error: --port requires an integer", file=sys.stderr)
+                raise SystemExit(1) from None
+            index += 1
+        elif arg == "--api-key":
+            index += 1
+            if index == len(args):
+                print("error: --api-key requires a value", file=sys.stderr)
+                raise SystemExit(1)
+            if args[index].startswith("-"):
+                print(f"error: unrecognized MCP option: {args[index]}", file=sys.stderr)
+                raise SystemExit(1)
+            api_key = args[index]
+            index += 1
+        elif arg.startswith("-"):
+            print(f"error: unrecognized MCP option: {arg}", file=sys.stderr)
+            raise SystemExit(1)
+        else:
+            paths.append(arg)
+            index += 1
+
+    api_key = (api_key or "").strip() or None
+    if transport == "http":
+        from graphify.serve import _validate_http_bind
+
+        try:
+            _validate_http_bind(host, api_key)
+        except ValueError as exc:
+            print(f"error: {exc}", file=sys.stderr)
+            raise SystemExit(1) from None
+
+    if transport == "stdio" and host == "127.0.0.1" and port == 8080 and api_key is None:
+        _serve_mcp_repositories(paths, transport=transport)
+    else:
+        _serve_mcp_repositories(paths, transport=transport, host=host, port=port, api_key=api_key)
+    return True
+
+
 def _run_cli() -> None:
     for _stream in (sys.stdout, sys.stderr):
         if _stream is not None and hasattr(_stream, "reconfigure"):
@@ -502,10 +628,18 @@ def _run_cli() -> None:
         print(f"graphify {__version__}")
         return
 
+    if _run_mcp_cli(sys.argv[1:]):
+        return
+
     if len(sys.argv) < 2 or sys.argv[1] in ("-h", "--help", "-?"):
         print("Usage: graphify <command>")
         print()
         print("Commands:")
+        print("  <repo>... --mcp         serve existing repository graphs over MCP stdio")
+        print("    --transport stdio|http transport (default: stdio)")
+        print("    --host HOST            HTTP bind host (default: 127.0.0.1)")
+        print("    --port PORT            HTTP bind port (default: 8080)")
+        print("    --api-key KEY          require this key for HTTP requests")
         print("  install [--platform P]  copy skill to platform config dir (claude|windows|codebuddy|codex|opencode|aider|amp|agents|claw|droid|trae|trae-cn|gemini|cursor|antigravity|hermes|kiro|pi|devin)")
         print("  uninstall               remove graphify from all detected platforms in one shot")
         print("    --purge                 also delete graphify-out/ directory")