23d889254bThe SEP spec and C# SDK use hooks (plural, JSON array) but the Go SDK
had hook (singular, single object). This meant the wire formats were
incompatible — Go would send `{"hook": {...}}` while everything else
expects `{"hooks": [...]}`.
Signed-off-by: Ukjae Jeong <jeongukjae@gmail.com>
60 lines
1.9 KiB
Markdown
60 lines
1.9 KiB
Markdown
# MCP Interceptors - Go Implementation
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Go implementation of the MCP Interceptor Extension based on
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[SEP-2624](https://github.com/modelcontextprotocol/modelcontextprotocol/issues/2624).
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Note: Currently the MCP SDK is vendored, in-order to add the Protocol Methods needed for interceptors.
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## Quick Start
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```go
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mcpServer := mcp.NewServer(&mcp.Implementation{
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Name: "my-server",
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Version: "0.1.0",
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}, nil)
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// Create an extension and register interceptors.
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ext := extension.New()
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// Register a validator that blocks dangerous tool calls.
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ext.AddInterceptor(&interceptors.Validator{
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Metadata: interceptors.Metadata{
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Name: "block-dangerous",
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Hooks: []interceptors.Hook{{
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Events: []string{interceptors.EventToolsCall},
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Phase: interceptors.PhaseRequest,
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}},
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Mode: interceptors.ModeEnforce,
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},
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Handler: func(_ context.Context, inv *interceptors.Invocation) (*interceptors.ValidationResult, error) {
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raw := inv.Payload.(json.RawMessage)
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var params struct{ Name string `json:"name"` }
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json.Unmarshal(raw, ¶ms)
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// validate the request...
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return &interceptors.ValidationResult{Valid: true}, nil
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},
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})
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// Install on the server and create a chain for middleware.
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ext.Install(mcpServer)
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chain, err := ext.LocalChain(ctx, mcpServer)
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mcpServer.AddReceivingMiddleware(gomiddleware.Middleware(chain))
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mcpServer.Run(context.Background(), &mcp.StdioTransport{})
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```
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See [`examples/`](examples/) for complete working examples.
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## Documentation
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- [**DESIGN.md**](doc/DESIGN.md) — architecture, execution model, integration
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with the go-sdk.
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- [**PERFORMANCE.md**](doc/PERFORMANCE.md) — per-request cost model, allocation
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summary, and optimization notes.
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- [**CONFORMANCE.md**](doc/CONFORMANCE.md) — SEP conformance status.
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Package API documentation is available via `go doc`:
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```sh
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go doc github.com/modelcontextprotocol/ext-interceptors/go/sdk/interceptors
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```
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