refactor: route TransportFor by provider name (#25650)

Delegate `aibridge` routing responsibility to the in-memory transport
layer.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

coderd/aibridge/factory.go

@@ -3,8 +3,6 @@ package aibridge
 import (
 	"context"
 	"net/http"
-
-	"github.com/google/uuid"
 )
 
 // Source identifies the call site that asked aibridge for a transport. It is
@@ -53,14 +51,20 @@ func DelegatedAPIKeyIDFromContext(ctx context.Context) (string, bool) {
 }
 
 // TransportFactory returns an [http.RoundTripper] that dispatches an aibridge
-// request in-process for a given ai_providers row.
+// request in-process for a given provider instance name.
 //
 // Implementations live in coderd/aibridged. coderd registers an in-process
 // factory on coderd.API.AIBridgeTransportFactory at startup so callers route
 // traffic through the daemon without going through the gated HTTP route.
 //
+// The returned RoundTripper is responsible for adapting the caller's request
+// to the aibridge daemon's mount path: callers hand it an upstream-shaped
+// request and the transport rewrites URL.Path to "/api/v2/aibridge/<name>/..."
+// before dispatching. Routing keys on the provider's instance name so callers
+// can use the same string the proxy daemon and the bridge mount use.
+//
 // Source is informational: implementations must not gate on it. It is attached
 // to the request context so handlers can include it in logs and metrics.
 type TransportFactory interface {
-	TransportFor(providerID uuid.UUID, source Source) (http.RoundTripper, error)
+	TransportFor(providerName string, source Source) (http.RoundTripper, error)
 }

coderd/aibridge_test.go

@@ -6,7 +6,6 @@ import (
 	"net/http/httptest"
 	"testing"
 
-	"github.com/google/uuid"
 	"github.com/stretchr/testify/require"
 
 	"github.com/coder/coder/v2/coderd/aibridge"
@@ -23,12 +22,12 @@ type stubTransportFactory struct {
 }
 
 type callRecord struct {
-	providerID uuid.UUID
-	source     aibridge.Source
+	providerName string
+	source       aibridge.Source
 }
 
-func (f *stubTransportFactory) TransportFor(providerID uuid.UUID, source aibridge.Source) (http.RoundTripper, error) {
-	f.calls <- callRecord{providerID: providerID, source: source}
+func (f *stubTransportFactory) TransportFor(providerName string, source aibridge.Source) (http.RoundTripper, error) {
+	f.calls <- callRecord{providerName: providerName, source: source}
 	return &handlerRoundTripper{handler: f.handler}, nil
 }
 
@@ -71,14 +70,14 @@ func TestAIBridgeTransportFactory_Registration(t *testing.T) {
 	loaded := api.AIBridgeTransportFactory.Load()
 	require.NotNil(t, loaded)
 
-	providerID := uuid.New()
-	rt, err := (*loaded).TransportFor(providerID, aibridge.SourceAgents)
+	providerName := "openai"
+	rt, err := (*loaded).TransportFor(providerName, aibridge.SourceAgents)
 	require.NoError(t, err)
 	require.NotNil(t, rt)
 
 	select {
 	case got := <-stub.calls:
-		require.Equal(t, providerID, got.providerID)
+		require.Equal(t, providerName, got.providerName)
 		require.Equal(t, aibridge.SourceAgents, got.source)
 	default:
 		t.Fatal("factory was not invoked")

coderd/aibridged/aibridged_test.go

@@ -321,7 +321,7 @@ func TestServeHTTP_DelegatedAPIKey_BYOK_Integration(t *testing.T) {
 	pool.EXPECT().Acquire(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Return(mockH, nil)
 
 	factory := aibridged.NewTransportFactory(srv)
-	rt, err := factory.TransportFor(uuid.New(), agplaibridge.SourceAgents)
+	rt, err := factory.TransportFor("openai", agplaibridge.SourceAgents)
 	require.NoError(t, err)
 
 	ctx := agplaibridge.WithDelegatedAPIKeyID(testutil.Context(t, testutil.WaitShort), testKeyID)
@@ -373,7 +373,7 @@ func TestServeHTTP_DelegatedAPIKey_Integration(t *testing.T) {
 	pool.EXPECT().Acquire(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Return(mockH, nil)
 
 	factory := aibridged.NewTransportFactory(srv)
-	rt, err := factory.TransportFor(uuid.New(), agplaibridge.SourceAgents)
+	rt, err := factory.TransportFor("openai", agplaibridge.SourceAgents)
 	require.NoError(t, err)
 
 	ctx := agplaibridge.WithDelegatedAPIKeyID(testutil.Context(t, testutil.WaitShort), testKeyID)

coderd/aibridged/transport.go

@@ -4,14 +4,21 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"sync"
 
-	"github.com/google/uuid"
 	"golang.org/x/xerrors"
 
 	"github.com/coder/coder/v2/coderd/aibridge"
 )
 
+// aibridgeRootPath is the URL prefix the in-memory aibridged handler
+// registers all of its routes under. The in-process round-tripper
+// prepends this plus the provider name to every request before
+// dispatch so callers can hand it upstream-shaped requests without
+// knowing the daemon's mount layout.
+const aibridgeRootPath = "/api/v2/aibridge"
+
 // NewTransportFactory returns an [aibridge.TransportFactory] whose RoundTripper
 // dispatches requests to handler in-process, streaming the response body
 // through an [io.Pipe] so SSE/NDJSON/chunked responses propagate token-by-token
@@ -28,20 +35,28 @@ type transportFactory struct {
 }
 
 // TransportFor returns an in-process [http.RoundTripper] that dispatches
-// requests through the aibridged handler. The source is attached to the
-// request context for downstream logging; routing does not depend on it.
-func (f *transportFactory) TransportFor(_ uuid.UUID, source aibridge.Source) (http.RoundTripper, error) {
+// requests through the aibridged handler. The provider name is the routing
+// key the daemon mounts on; the round-tripper rewrites each request's URL
+// path to "/api/v2/aibridge/<providerName>/..." before dispatching so
+// callers can build upstream-shaped requests and stay agnostic of the
+// daemon's mount layout. The source is attached to the request context for
+// downstream logging; routing does not depend on it.
+func (f *transportFactory) TransportFor(providerName string, source aibridge.Source) (http.RoundTripper, error) {
 	if f.handler == nil {
 		return nil, xerrors.New("aibridged handler not registered")
 	}
-	return &inMemoryRoundTripper{handler: f.handler, source: source}, nil
+	if providerName == "" {
+		return nil, xerrors.New("provider name is required")
+	}
+	return &inMemoryRoundTripper{handler: f.handler, providerName: providerName, source: source}, nil
 }
 
 // inMemoryRoundTripper implements [http.RoundTripper] by invoking handler
 // in a goroutine and streaming its response back through an [io.Pipe].
 type inMemoryRoundTripper struct {
-	handler http.Handler
-	source  aibridge.Source
+	handler      http.Handler
+	providerName string
+	source       aibridge.Source
 }
 
 func (t *inMemoryRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
@@ -53,6 +68,17 @@ func (t *inMemoryRoundTripper) RoundTrip(req *http.Request) (*http.Response, err
 		return nil, xerrors.New("aibridged in-memory transport requires WithDelegatedAPIKeyID on the request context")
 	}
 
+	// Adapt the caller's upstream-shaped URL to the daemon's mount layout:
+	// "/api/v2/aibridge/<providerName>/<original-path>". Done here so
+	// callers do not need to encode the mount prefix or the provider
+	// routing key into the requests they hand to the transport.
+	newPath, err := url.JoinPath(aibridgeRootPath, t.providerName, req.URL.Path)
+	if err != nil {
+		return nil, xerrors.Errorf("rewrite request URL for provider %q: %w", t.providerName, err)
+	}
+	req = req.Clone(req.Context())
+	req.URL.Path = newPath
+
 	pr, pw := io.Pipe()
 	rw := &pipeResponseWriter{
 		header:     http.Header{},

coderd/aibridged/transport_test.go

@@ -10,7 +10,6 @@ import (
 	"sync"
 	"testing"
 
-	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"golang.org/x/xerrors"
@@ -26,7 +25,7 @@ func TestTransportFactory_TransportFor(t *testing.T) {
 	t.Run("ReturnsTransport", func(t *testing.T) {
 		t.Parallel()
 		f := aibridged.NewTransportFactory(http.NotFoundHandler())
-		rt, err := f.TransportFor(uuid.New(), aibridge.SourceAgents)
+		rt, err := f.TransportFor("openai", aibridge.SourceAgents)
 		require.NoError(t, err)
 		require.NotNil(t, rt)
 	})
@@ -34,10 +33,51 @@ func TestTransportFactory_TransportFor(t *testing.T) {
 	t.Run("NilHandlerErrors", func(t *testing.T) {
 		t.Parallel()
 		f := aibridged.NewTransportFactory(nil)
-		_, err := f.TransportFor(uuid.New(), aibridge.SourceAgents)
+		_, err := f.TransportFor("openai", aibridge.SourceAgents)
 		require.Error(t, err)
 	})
 
+	t.Run("EmptyProviderErrors", func(t *testing.T) {
+		t.Parallel()
+		f := aibridged.NewTransportFactory(http.NotFoundHandler())
+		_, err := f.TransportFor("", aibridge.SourceAgents)
+		require.Error(t, err)
+	})
+
+	t.Run("RewritesURLToAibridgeMount", func(t *testing.T) {
+		t.Parallel()
+
+		// The round-tripper must adapt an upstream-shaped URL.Path
+		// ("/v1/messages") to the aibridge mount layout
+		// ("/api/v2/aibridge/<provider>/v1/messages") so callers don't
+		// have to encode the daemon's routing key into their requests.
+		got := make(chan string, 1)
+		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			got <- r.URL.Path
+			w.WriteHeader(http.StatusOK)
+		})
+
+		rt, err := aibridged.NewTransportFactory(handler).TransportFor("my-anthropic", aibridge.SourceAgents)
+		require.NoError(t, err)
+
+		ctx := aibridge.WithDelegatedAPIKeyID(testutil.Context(t, testutil.WaitShort), "test-key-id")
+		req, err := http.NewRequestWithContext(ctx, http.MethodPost, "http://upstream/v1/messages", nil)
+		require.NoError(t, err)
+
+		// The caller's req.URL.Path is the upstream shape. Capture it so
+		// we can prove the transport mutates a clone, not the caller's
+		// request, after RoundTrip returns.
+		origPath := req.URL.Path
+
+		resp, err := rt.RoundTrip(req)
+		require.NoError(t, err)
+		defer resp.Body.Close()
+
+		require.Equal(t, "/api/v2/aibridge/my-anthropic/v1/messages", <-got)
+		require.Equal(t, origPath, req.URL.Path,
+			"caller's request URL must not be mutated by RoundTrip")
+	})
+
 	t.Run("AttachesSourceToContext", func(t *testing.T) {
 		t.Parallel()
 
@@ -47,7 +87,7 @@ func TestTransportFactory_TransportFor(t *testing.T) {
 			w.WriteHeader(http.StatusOK)
 		})
 
-		rt, err := aibridged.NewTransportFactory(handler).TransportFor(uuid.New(), aibridge.SourceAgents)
+		rt, err := aibridged.NewTransportFactory(handler).TransportFor("openai", aibridge.SourceAgents)
 		require.NoError(t, err)
 
 		ctx := aibridge.WithDelegatedAPIKeyID(testutil.Context(t, testutil.WaitShort), "test-key-id")
@@ -72,7 +112,7 @@ func TestInMemoryRoundTripper_PassesHeadersAndStatus(t *testing.T) {
 		_, _ = w.Write([]byte(`{"ok":true}`))
 	})
 
-	rt, err := aibridged.NewTransportFactory(handler).TransportFor(uuid.New(), aibridge.SourceAgents)
+	rt, err := aibridged.NewTransportFactory(handler).TransportFor("openai", aibridge.SourceAgents)
 	require.NoError(t, err)
 
 	ctx := aibridge.WithDelegatedAPIKeyID(testutil.Context(t, testutil.WaitShort), "test-key-id")
@@ -122,7 +162,7 @@ func TestInMemoryRoundTripper_Streams(t *testing.T) {
 		}
 	})
 
-	rt, err := aibridged.NewTransportFactory(handler).TransportFor(uuid.New(), aibridge.SourceAgents)
+	rt, err := aibridged.NewTransportFactory(handler).TransportFor("openai", aibridge.SourceAgents)
 	require.NoError(t, err)
 
 	ctx := aibridge.WithDelegatedAPIKeyID(testutil.Context(t, testutil.WaitShort), "test-key-id")
@@ -161,7 +201,7 @@ func TestInMemoryRoundTripper_CancelCloses(t *testing.T) {
 		close(handlerCtxObserved)
 	})
 
-	rt, err := aibridged.NewTransportFactory(handler).TransportFor(uuid.New(), aibridge.SourceAgents)
+	rt, err := aibridged.NewTransportFactory(handler).TransportFor("openai", aibridge.SourceAgents)
 	require.NoError(t, err)
 
 	parentCtx := testutil.Context(t, testutil.WaitShort)
@@ -199,7 +239,7 @@ func TestInMemoryRoundTripper_ConcurrentRequests(t *testing.T) {
 		_, _ = w.Write(body)
 	})
 
-	rt, err := aibridged.NewTransportFactory(handler).TransportFor(uuid.New(), aibridge.SourceAgents)
+	rt, err := aibridged.NewTransportFactory(handler).TransportFor("openai", aibridge.SourceAgents)
 	require.NoError(t, err)
 
 	const n = 16
@@ -248,7 +288,7 @@ func TestInMemoryRoundTripper_HandlerPanic(t *testing.T) {
 		panic("unexpected nil pointer")
 	})
 
-	rt, err := aibridged.NewTransportFactory(handler).TransportFor(uuid.New(), aibridge.SourceAgents)
+	rt, err := aibridged.NewTransportFactory(handler).TransportFor("openai", aibridge.SourceAgents)
 	require.NoError(t, err)
 
 	ctx := aibridge.WithDelegatedAPIKeyID(testutil.Context(t, testutil.WaitShort), "test-key-id")
@@ -307,7 +347,7 @@ func TestInMemoryRoundTripper_RequiresDelegatedAPIKeyID(t *testing.T) {
 				w.WriteHeader(http.StatusOK)
 			})
 
-			rt, err := aibridged.NewTransportFactory(handler).TransportFor(uuid.New(), aibridge.SourceAgents)
+			rt, err := aibridged.NewTransportFactory(handler).TransportFor("openai", aibridge.SourceAgents)
 			require.NoError(t, err)
 
 			ctx := tc.withCtx(testutil.Context(t, testutil.WaitShort))
@@ -340,7 +380,7 @@ func TestInMemoryRoundTripper_HandlerReturnsWithoutWriting(t *testing.T) {
 
 	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {})
 
-	rt, err := aibridged.NewTransportFactory(handler).TransportFor(uuid.New(), aibridge.SourceAgents)
+	rt, err := aibridged.NewTransportFactory(handler).TransportFor("openai", aibridge.SourceAgents)
 	require.NoError(t, err)
 
 	ctx := aibridge.WithDelegatedAPIKeyID(testutil.Context(t, testutil.WaitShort), "test-key-id")