feat(resolvemcp): enhance handler with configuration support

* Introduce Config struct for BaseURL and BasePath settings
* Update handler creation functions to accept configuration
* Modify SSEServer to use dynamic base URL detection
* Adjust route setup functions to utilize BasePath from config
This commit is contained in:
Hein
2026-03-27 13:56:03 +02:00
parent 200a03c225
commit 1641eaf278
3 changed files with 140 additions and 71 deletions

View File

@@ -11,7 +11,9 @@ import (
) )
// 1. Create a handler // 1. Create a handler
handler := resolvemcp.NewHandlerWithGORM(db) handler := resolvemcp.NewHandlerWithGORM(db, resolvemcp.Config{
BaseURL: "http://localhost:8080",
})
// 2. Register models // 2. Register models
handler.RegisterModel("public", "users", &User{}) handler.RegisterModel("public", "users", &User{})
@@ -19,19 +21,35 @@ handler.RegisterModel("public", "orders", &Order{})
// 3. Mount routes // 3. Mount routes
r := mux.NewRouter() r := mux.NewRouter()
resolvemcp.SetupMuxRoutes(r, handler, "http://localhost:8080") resolvemcp.SetupMuxRoutes(r, handler)
``` ```
--- ---
## Config
```go
type Config struct {
// BaseURL is the public-facing base URL of the server (e.g. "http://localhost:8080").
// Sent to MCP clients during the SSE handshake so they know where to POST messages.
// If empty, it is detected from each incoming request using the Host header and
// TLS state (X-Forwarded-Proto is honoured for reverse-proxy deployments).
BaseURL string
// BasePath is the URL path prefix where MCP endpoints are mounted (e.g. "/mcp").
// Required.
BasePath string
}
```
## Handler Creation ## Handler Creation
| Function | Description | | Function | Description |
|---|---| |---|---|
| `NewHandlerWithGORM(db *gorm.DB) *Handler` | Backed by GORM | | `NewHandlerWithGORM(db *gorm.DB, cfg Config) *Handler` | Backed by GORM |
| `NewHandlerWithBun(db *bun.DB) *Handler` | Backed by Bun | | `NewHandlerWithBun(db *bun.DB, cfg Config) *Handler` | Backed by Bun |
| `NewHandlerWithDB(db common.Database) *Handler` | Backed by any `common.Database` | | `NewHandlerWithDB(db common.Database, cfg Config) *Handler` | Backed by any `common.Database` |
| `NewHandler(db common.Database, registry common.ModelRegistry) *Handler` | Full control over registry | | `NewHandler(db common.Database, registry common.ModelRegistry, cfg Config) *Handler` | Full control over registry |
--- ---
@@ -53,40 +71,43 @@ Each call immediately creates four MCP **tools** and one MCP **resource** for th
The `*server.SSEServer` returned by any of the helpers below implements `http.Handler`, so it works with every Go HTTP framework. The `*server.SSEServer` returned by any of the helpers below implements `http.Handler`, so it works with every Go HTTP framework.
`Config.BasePath` is required and used for all route registration.
`Config.BaseURL` is optional — when empty it is detected from each request.
### Gorilla Mux ### Gorilla Mux
```go ```go
resolvemcp.SetupMuxRoutes(r, handler, "http://localhost:8080") resolvemcp.SetupMuxRoutes(r, handler)
``` ```
Registers: Registers:
| Route | Method | Description | | Route | Method | Description |
|---|---|---| |---|---|---|
| `/mcp/sse` | GET | SSE connection — clients subscribe here | | `{BasePath}/sse` | GET | SSE connection — clients subscribe here |
| `/mcp/message` | POST | JSON-RPC — clients send requests here | | `{BasePath}/message` | POST | JSON-RPC — clients send requests here |
| `/mcp/*` | any | Full SSE server (convenience prefix) | | `{BasePath}/*` | any | Full SSE server (convenience prefix) |
### bunrouter ### bunrouter
```go ```go
resolvemcp.SetupBunRouterRoutes(router, handler, "http://localhost:8080", "/mcp") resolvemcp.SetupBunRouterRoutes(router, handler)
``` ```
Registers `GET /mcp/sse` and `POST /mcp/message` on the provided `*bunrouter.Router`. Registers `GET {BasePath}/sse` and `POST {BasePath}/message` on the provided `*bunrouter.Router`.
### Gin (or any `http.Handler`-compatible framework) ### Gin (or any `http.Handler`-compatible framework)
Use `handler.SSEServer` to get a pre-bound `*server.SSEServer` and wrap it with the framework's adapter: Use `handler.SSEServer()` to get an `http.Handler` and wrap it with the framework's adapter:
```go ```go
sse := handler.SSEServer("http://localhost:8080", "/mcp") sse := handler.SSEServer()
// Gin // Gin
engine.Any("/mcp/*path", gin.WrapH(sse)) engine.Any("/mcp/*path", gin.WrapH(sse))
// net/http // net/http
http.Handle("/mcp/", http.StripPrefix("/mcp", sse)) http.Handle("/mcp/", sse)
// Echo // Echo
e.Any("/mcp/*", echo.WrapHandler(sse)) e.Any("/mcp/*", echo.WrapHandler(sse))

View File

@@ -5,8 +5,10 @@ import (
"database/sql" "database/sql"
"encoding/json" "encoding/json"
"fmt" "fmt"
"net/http"
"reflect" "reflect"
"strings" "strings"
"sync"
"github.com/mark3labs/mcp-go/server" "github.com/mark3labs/mcp-go/server"
@@ -21,17 +23,19 @@ type Handler struct {
registry common.ModelRegistry registry common.ModelRegistry
hooks *HookRegistry hooks *HookRegistry
mcpServer *server.MCPServer mcpServer *server.MCPServer
config Config
name string name string
version string version string
} }
// NewHandler creates a Handler with the given database and model registry. // NewHandler creates a Handler with the given database, model registry, and config.
func NewHandler(db common.Database, registry common.ModelRegistry) *Handler { func NewHandler(db common.Database, registry common.ModelRegistry, cfg Config) *Handler {
return &Handler{ return &Handler{
db: db, db: db,
registry: registry, registry: registry,
hooks: NewHookRegistry(), hooks: NewHookRegistry(),
mcpServer: server.NewMCPServer("resolvemcp", "1.0.0"), mcpServer: server.NewMCPServer("resolvemcp", "1.0.0"),
config: cfg,
name: "resolvemcp", name: "resolvemcp",
version: "1.0.0", version: "1.0.0",
} }
@@ -52,12 +56,18 @@ func (h *Handler) MCPServer() *server.MCPServer {
return h.mcpServer return h.mcpServer
} }
// SSEServer creates an *server.SSEServer bound to this handler. // SSEServer returns an http.Handler that serves MCP over SSE.
// Use it to mount MCP on any HTTP framework that accepts http.Handler. // Config.BasePath must be set. Config.BaseURL is used when set; if empty it is
// // detected automatically from each incoming request.
// sse := handler.SSEServer("http://localhost:8080", "/mcp") func (h *Handler) SSEServer() http.Handler {
// ginEngine.Any("/mcp/*path", gin.WrapH(sse)) if h.config.BaseURL != "" {
func (h *Handler) SSEServer(baseURL, basePath string) *server.SSEServer { return h.newSSEServer(h.config.BaseURL, h.config.BasePath)
}
return &dynamicSSEHandler{h: h}
}
// newSSEServer creates a concrete *server.SSEServer for known baseURL and basePath values.
func (h *Handler) newSSEServer(baseURL, basePath string) *server.SSEServer {
return server.NewSSEServer( return server.NewSSEServer(
h.mcpServer, h.mcpServer,
server.WithBaseURL(baseURL), server.WithBaseURL(baseURL),
@@ -65,6 +75,44 @@ func (h *Handler) SSEServer(baseURL, basePath string) *server.SSEServer {
) )
} }
// dynamicSSEHandler detects BaseURL from each request and delegates to a cached
// *server.SSEServer per detected baseURL. Used when Config.BaseURL is empty.
type dynamicSSEHandler struct {
h *Handler
mu sync.Mutex
pool map[string]*server.SSEServer
}
func (d *dynamicSSEHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
baseURL := requestBaseURL(r)
d.mu.Lock()
if d.pool == nil {
d.pool = make(map[string]*server.SSEServer)
}
s, ok := d.pool[baseURL]
if !ok {
s = d.h.newSSEServer(baseURL, d.h.config.BasePath)
d.pool[baseURL] = s
}
d.mu.Unlock()
s.ServeHTTP(w, r)
}
// requestBaseURL builds the base URL from an incoming request.
// It honours the X-Forwarded-Proto header for deployments behind a proxy.
func requestBaseURL(r *http.Request) string {
scheme := "http"
if r.TLS != nil {
scheme = "https"
}
if proto := r.Header.Get("X-Forwarded-Proto"); proto != "" {
scheme = proto
}
return scheme + "://" + r.Host
}
// RegisterModel registers a model and immediately exposes it as MCP tools and a resource. // RegisterModel registers a model and immediately exposes it as MCP tools and a resource.
func (h *Handler) RegisterModel(schema, entity string, model interface{}) error { func (h *Handler) RegisterModel(schema, entity string, model interface{}) error {
fullName := buildModelName(schema, entity) fullName := buildModelName(schema, entity)

View File

@@ -8,18 +8,17 @@
// //
// Usage: // Usage:
// //
// handler := resolvemcp.NewHandlerWithGORM(db) // handler := resolvemcp.NewHandlerWithGORM(db, resolvemcp.Config{BaseURL: "http://localhost:8080"})
// handler.RegisterModel("public", "users", &User{}) // handler.RegisterModel("public", "users", &User{})
// //
// r := mux.NewRouter() // r := mux.NewRouter()
// resolvemcp.SetupMuxRoutes(r, handler, "http://localhost:8080") // resolvemcp.SetupMuxRoutes(r, handler)
package resolvemcp package resolvemcp
import ( import (
"net/http" "net/http"
"github.com/gorilla/mux" "github.com/gorilla/mux"
"github.com/mark3labs/mcp-go/server"
"github.com/uptrace/bun" "github.com/uptrace/bun"
bunrouter "github.com/uptrace/bunrouter" bunrouter "github.com/uptrace/bunrouter"
"gorm.io/gorm" "gorm.io/gorm"
@@ -29,72 +28,73 @@ import (
"github.com/bitechdev/ResolveSpec/pkg/modelregistry" "github.com/bitechdev/ResolveSpec/pkg/modelregistry"
) )
// Config holds configuration for the resolvemcp handler.
type Config struct {
// BaseURL is the public-facing base URL of the server (e.g. "http://localhost:8080").
// It is sent to MCP clients during the SSE handshake so they know where to POST messages.
BaseURL string
// BasePath is the URL path prefix where the MCP endpoints are mounted (e.g. "/mcp").
// If empty, the path is detected from each incoming request automatically.
BasePath string
}
// NewHandlerWithGORM creates a Handler backed by a GORM database connection. // NewHandlerWithGORM creates a Handler backed by a GORM database connection.
func NewHandlerWithGORM(db *gorm.DB) *Handler { func NewHandlerWithGORM(db *gorm.DB, cfg Config) *Handler {
return NewHandler(database.NewGormAdapter(db), modelregistry.NewModelRegistry()) return NewHandler(database.NewGormAdapter(db), modelregistry.NewModelRegistry(), cfg)
} }
// NewHandlerWithBun creates a Handler backed by a Bun database connection. // NewHandlerWithBun creates a Handler backed by a Bun database connection.
func NewHandlerWithBun(db *bun.DB) *Handler { func NewHandlerWithBun(db *bun.DB, cfg Config) *Handler {
return NewHandler(database.NewBunAdapter(db), modelregistry.NewModelRegistry()) return NewHandler(database.NewBunAdapter(db), modelregistry.NewModelRegistry(), cfg)
} }
// NewHandlerWithDB creates a Handler using an existing common.Database and a new registry. // NewHandlerWithDB creates a Handler using an existing common.Database and a new registry.
func NewHandlerWithDB(db common.Database) *Handler { func NewHandlerWithDB(db common.Database, cfg Config) *Handler {
return NewHandler(db, modelregistry.NewModelRegistry()) return NewHandler(db, modelregistry.NewModelRegistry(), cfg)
} }
// SetupMuxRoutes mounts the MCP HTTP/SSE endpoints on the given Gorilla Mux router. // SetupMuxRoutes mounts the MCP HTTP/SSE endpoints on the given Gorilla Mux router
// // using the base path from Config.BasePath (falls back to "/mcp" if empty).
// baseURL is the public-facing base URL of the server (e.g. "http://localhost:8080").
// It is sent to MCP clients during the SSE handshake so they know where to POST messages.
// //
// Two routes are registered: // Two routes are registered:
// - GET /mcp/sse — SSE connection endpoint (client subscribes here) // - GET {basePath}/sse — SSE connection endpoint (client subscribes here)
// - POST /mcp/message — JSON-RPC message endpoint (client sends requests here) // - POST {basePath}/message — JSON-RPC message endpoint (client sends requests here)
// //
// To protect these routes with authentication, wrap the mux router or apply middleware // To protect these routes with authentication, wrap the mux router or apply middleware
// before calling SetupMuxRoutes. // before calling SetupMuxRoutes.
func SetupMuxRoutes(muxRouter *mux.Router, handler *Handler, baseURL string) { func SetupMuxRoutes(muxRouter *mux.Router, handler *Handler) {
sseServer := server.NewSSEServer( basePath := handler.config.BasePath
handler.mcpServer, h := handler.SSEServer()
server.WithBaseURL(baseURL),
server.WithBasePath("/mcp"),
)
muxRouter.Handle("/mcp/sse", sseServer.SSEHandler()).Methods("GET", "OPTIONS") muxRouter.Handle(basePath+"/sse", h).Methods("GET", "OPTIONS")
muxRouter.Handle("/mcp/message", sseServer.MessageHandler()).Methods("POST", "OPTIONS") muxRouter.Handle(basePath+"/message", h).Methods("POST", "OPTIONS")
// Convenience: also expose the full SSE server at /mcp for clients that // Convenience: also expose the full SSE server at basePath for clients that
// use ServeHTTP directly (e.g. net/http default mux). // use ServeHTTP directly (e.g. net/http default mux).
muxRouter.PathPrefix("/mcp").Handler(http.StripPrefix("/mcp", sseServer)) muxRouter.PathPrefix(basePath).Handler(http.StripPrefix(basePath, h))
} }
// NewSSEServer creates an *server.SSEServer that can be mounted manually, // SetupBunRouterRoutes mounts the MCP HTTP/SSE endpoints on a bunrouter router
// useful when integrating with non-Mux routers or adding extra middleware. // using the base path from Config.BasePath.
// //
// sseServer := resolvemcp.NewSSEServer(handler, "http://localhost:8080", "/mcp") // Two routes are registered:
// http.Handle("/mcp/", http.StripPrefix("/mcp", sseServer))
func NewSSEServer(handler *Handler, baseURL, basePath string) *server.SSEServer {
return server.NewSSEServer(
handler.mcpServer,
server.WithBaseURL(baseURL),
server.WithBasePath(basePath),
)
}
// SetupBunRouterRoutes mounts the MCP HTTP/SSE endpoints on a bunrouter router.
//
// Two routes are registered under the given basePath prefix:
// - GET {basePath}/sse — SSE connection endpoint // - GET {basePath}/sse — SSE connection endpoint
// - POST {basePath}/message — JSON-RPC message endpoint // - POST {basePath}/message — JSON-RPC message endpoint
func SetupBunRouterRoutes(router *bunrouter.Router, handler *Handler, baseURL, basePath string) { func SetupBunRouterRoutes(router *bunrouter.Router, handler *Handler) {
sseServer := server.NewSSEServer( basePath := handler.config.BasePath
handler.mcpServer, h := handler.SSEServer()
server.WithBaseURL(baseURL),
server.WithBasePath(basePath),
)
router.GET(basePath+"/sse", bunrouter.HTTPHandler(sseServer.SSEHandler())) router.GET(basePath+"/sse", bunrouter.HTTPHandler(h))
router.POST(basePath+"/message", bunrouter.HTTPHandler(sseServer.MessageHandler())) router.POST(basePath+"/message", bunrouter.HTTPHandler(h))
}
// NewSSEServer returns an http.Handler that serves MCP over SSE.
// If Config.BasePath is set it is used directly; otherwise the base path is
// detected from each incoming request (by stripping the "/sse" or "/message" suffix).
//
// h := resolvemcp.NewSSEServer(handler)
// http.Handle("/api/mcp/", h)
func NewSSEServer(handler *Handler) http.Handler {
return handler.SSEServer()
} }