[management,proxy] Add agentgateway integration (#7274)

* [management] Add agentgateway provider catalog entry

Allow Agent Network providers to target an operator-supplied agentgateway proxy while stamping trusted NetBird identity headers.

Signed-off-by: Daneyon Hansen <daneyon.hansen@solo.io>

* [proxy] Allow trusted Agent Network identity headers

Permit only the built-in identity injector to replace the two reserved agentgateway attribution headers while keeping them blocked for every other middleware.

Signed-off-by: Daneyon Hansen <daneyon.hansen@solo.io>

* [management,proxy] Add multi-vendor gateway routing

Let one Agent Network route declare multiple parser surfaces while preserving the existing singular vendor wire field.

Signed-off-by: Daneyon Hansen <daneyon.hansen@solo.io>

* [management] Update router test for model policies

Signed-off-by: Daneyon Hansen <daneyon.hansen@solo.io>

* [proxy] Cover reserved header policy

Signed-off-by: Daneyon Hansen <daneyon.hansen@solo.io>

* [management] Add agentgateway model discovery

Use agentgateway's OpenAI-compatible models endpoint and omit wildcard patterns until NetBird can authorize and price them consistently.

Signed-off-by: Daneyon Hansen <daneyon.hansen@solo.io>

---------

Signed-off-by: Daneyon Hansen <daneyon.hansen@solo.io>

proxy/internal/middleware/builtin/llm_router/factory.go

@@ -36,7 +36,10 @@ type ProviderRoute struct {
 	// request on a same-vendor route so catch-all gateways of a different
 	// vendor can't swallow it. Empty disables vendor filtering for this
 	// route.
-	Vendor          string   `json:"vendor,omitempty"`
+	Vendor string `json:"vendor,omitempty"`
+	// Vendors lists every parser surface a multi-surface gateway accepts.
+	// Vendor remains supported for existing single-surface configurations.
+	Vendors         []string `json:"vendors,omitempty"`
 	Models          []string `json:"models"`
 	UpstreamScheme  string   `json:"upstream_scheme"`
 	UpstreamHost    string   `json:"upstream_host"`

proxy/internal/middleware/builtin/llm_router/middleware.go

@@ -409,7 +409,7 @@ func stripBedrockNamespace(out *middleware.Output) {
 //     peer, return matchOutcomeUnauthorised so the caller can emit
 //     the dedicated no_authorised_provider deny code.
 //  3. Vendor precedence: when the request carries a detected vendor
-//     (llm.provider) and at least one candidate is the same vendor,
+//     (llm.provider) and at least one candidate declares that vendor,
 //     drop the rest — a vendor-tagged request must never cross to
 //     another vendor's route (e.g. an Anthropic call landing on an
 //     OpenAI-compatible gateway that also claims the model).
@@ -432,9 +432,9 @@ func (m *Middleware) matchRoute(model, vendor, reqPath string, userGroups []stri
 
 	// Vendor pinning runs BEFORE the group filter so a request the parser
 	// tagged with a vendor can never cross to another vendor's route — not
-	// even an authorised one. Narrow to same-vendor routes when any
-	// model-matched route declares that vendor; setups with no vendor tag on
-	// any route fall through unchanged. After narrowing, if no same-vendor
+	// even an authorised one. Narrow to supporting routes when any
+	// model-matched route declares that vendor; setups with no matching vendor
+	// declaration fall through unchanged. After narrowing, if no supporting
 	// route authorises the caller, that's matchOutcomeUnauthorised (no
 	// cross-vendor fallback).
 	if vendor != "" {
@@ -805,21 +805,31 @@ func authorisingGroupsCSV(routeGroups, userGroups []string) string {
 	return strings.Join(out, ",")
 }
 
-// matchingVendor returns the subset of routes whose Vendor equals the
-// request's detected vendor. Routes with an empty Vendor never match — an
-// untagged route can't be asserted to speak the request's surface, so it
-// stays out of the vendor-filtered set (but remains eligible via the
-// fall-through when no route matches the vendor at all).
+// matchingVendor returns the routes that declare the request's detected
+// vendor through either the legacy singular field or the multi-vendor field.
+// Untagged routes remain eligible only when no route declares the vendor.
 func matchingVendor(routes []ProviderRoute, vendor string) []ProviderRoute {
 	var out []ProviderRoute
 	for _, r := range routes {
-		if r.Vendor == vendor {
+		if routeSupportsVendor(r, vendor) {
 			out = append(out, r)
 		}
 	}
 	return out
 }
 
+func routeSupportsVendor(route ProviderRoute, vendor string) bool {
+	if route.Vendor == vendor {
+		return true
+	}
+	for _, candidate := range route.Vendors {
+		if candidate == vendor {
+			return true
+		}
+	}
+	return false
+}
+
 // explicitlyClaiming returns the subset of routes whose Models list
 // names the model exactly. Catch-all routes (empty Models) are excluded,
 // so callers can prefer a provider that genuinely declares the model over

proxy/internal/middleware/builtin/llm_router/middleware_test.go

@@ -412,6 +412,50 @@ func TestRouter_VendorKeepsOpenAIOffAnthropic(t *testing.T) {
 	assert.Equal(t, "api.openai.com", out.Mutations.RewriteUpstream.Host, "openai vendor must pin to the openai route despite anthropic being declared first")
 }
 
+func TestRouter_MultiVendorGatewayAcceptsBothSurfaces(t *testing.T) {
+	gateway := ProviderRoute{
+		ID:              "agentgateway",
+		Vendors:         []string{"openai", "anthropic"},
+		Models:          nil,
+		AllowedGroupIDs: []string{defaultTestGroup},
+		UpstreamScheme:  "https",
+		UpstreamHost:    "gateway.example.com",
+	}
+	other := ProviderRoute{
+		ID:              "other-vendor",
+		Vendor:          "mistral",
+		Models:          nil,
+		AllowedGroupIDs: []string{defaultTestGroup},
+		UpstreamScheme:  "https",
+		UpstreamHost:    "mistral.example.com",
+	}
+	mw := New(Config{Providers: []ProviderRoute{other, gateway}})
+
+	for _, tc := range []struct {
+		name   string
+		vendor string
+		model  string
+		path   string
+	}{
+		{name: "OpenAI", vendor: "openai", model: "gpt-4o-mini", path: "/v1/chat/completions"},
+		{name: "Anthropic", vendor: "anthropic", model: "claude-sonnet-4-5", path: "/v1/messages"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			out, err := mw.Invoke(context.Background(), newInputVendorModelURL(tc.vendor, tc.model, tc.path))
+			require.NoError(t, err)
+			require.NotNil(t, out)
+			assert.Equal(t, middleware.DecisionAllow, out.Decision,
+				"supported vendor must route through the multi-surface gateway")
+			require.NotNil(t, out.Mutations)
+			require.NotNil(t, out.Mutations.RewriteUpstream)
+			assert.Equal(t, "gateway.example.com", out.Mutations.RewriteUpstream.Host)
+
+			provider, _ := metaValue(t, out.Metadata, middleware.KeyLLMResolvedProviderID)
+			assert.Equal(t, "agentgateway", provider)
+		})
+	}
+}
+
 // TestRouter_VendorAbsentFallsBackToModelPath confirms vendor filtering is
 // inert when the request carries no detected vendor: routing then relies on
 // model/path as before.
@@ -692,6 +736,23 @@ func TestRouter_FactoryRejectsBadJSON(t *testing.T) {
 	require.Error(t, err, "malformed JSON config must be rejected at chain build time")
 }
 
+func TestRouter_FactoryDecodesLegacyAndMultiVendorFields(t *testing.T) {
+	raw := []byte(`{"providers":[` +
+		`{"id":"legacy","vendor":"openai","models":[],"upstream_scheme":"https","upstream_host":"openai.example.com","auth_header_name":"Authorization","auth_header_value":"Bearer legacy","allowed_group_ids":["group"]},` +
+		`{"id":"multi","vendors":["openai","anthropic"],"models":[],"upstream_scheme":"https","upstream_host":"gateway.example.com","auth_header_name":"Authorization","auth_header_value":"Bearer multi","allowed_group_ids":["group"]}` +
+		`]}`)
+
+	resolved, err := Factory{}.New(raw)
+	require.NoError(t, err)
+	router, ok := resolved.(*Middleware)
+	require.True(t, ok, "factory must return the concrete router middleware")
+	require.Len(t, router.cfg.Providers, 2)
+	assert.Equal(t, "openai", router.cfg.Providers[0].Vendor,
+		"the legacy singular field must keep decoding")
+	assert.Equal(t, []string{"openai", "anthropic"}, router.cfg.Providers[1].Vendors,
+		"the multi-vendor field must decode both supported surfaces")
+}
+
 func TestRouter_FactoryAcceptsEmptyShapes(t *testing.T) {
 	cases := [][]byte{nil, []byte(""), []byte(" "), []byte("null"), []byte("{}"), []byte("[]")}
 	for _, raw := range cases {

proxy/internal/middleware/chain.go

@@ -264,7 +264,7 @@ func applyMutations(ctx context.Context, d *Dispatcher, spec Spec, r *http.Reque
 	if m == nil {
 		return
 	}
-	add, remove, blocked := FilterHeaderMutations(m)
+	add, remove, blocked := filterHeaderMutations(m, spec.ID)
 	for _, h := range blocked {
 		d.metrics.IncHeaderMutationBlocked(ctx, spec.ID, h)
 	}

proxy/internal/middleware/chain_test.go

@@ -2,6 +2,7 @@ package middleware
 
 import (
 	"context"
+	"net/http"
 	"strconv"
 	"testing"
 
@@ -278,6 +279,64 @@ func TestChain_ApplyMutations_RewriteGatedOnCanMutate(t *testing.T) {
 	assert.Nil(t, rewrite, "rewrite must be filtered when CanMutate=false")
 }
 
+func TestChain_IdentityInjectReplacesReservedNetBirdHeaders(t *testing.T) {
+	mw := &fakeMiddleware{
+		id:                 "llm_identity_inject",
+		slot:               SlotOnRequest,
+		mutationsSupported: true,
+		canMutate:          true,
+		mutations: &Mutations{
+			HeadersRemove: []string{"x-netbird-user-id", "x-netbird-groups"},
+			HeadersAdd: []KV{
+				{Key: "x-netbird-user-id", Value: "trusted-user"},
+				{Key: "x-netbird-groups", Value: "trusted-group"},
+			},
+		},
+	}
+	c := chainFor(t, mw)
+	req, err := http.NewRequest(http.MethodGet, "https://gateway.example.com/v1/models", nil)
+	require.NoError(t, err)
+	req.Header.Set("x-netbird-user-id", "spoofed-user")
+	req.Header.Set("x-netbird-groups", "spoofed-group")
+
+	denied, _, _, err := c.RunRequest(context.Background(), req, &Input{}, NewAccumulator(0))
+	require.NoError(t, err)
+	assert.Nil(t, denied, "identity injection must not deny the request")
+	assert.Equal(t, "trusted-user", req.Header.Get("x-netbird-user-id"),
+		"the built-in identity middleware must replace a spoofed user header")
+	assert.Equal(t, "trusted-group", req.Header.Get("x-netbird-groups"),
+		"the built-in identity middleware must replace spoofed groups")
+}
+
+func TestChain_OtherMiddlewareCannotReplaceReservedNetBirdHeaders(t *testing.T) {
+	mw := &fakeMiddleware{
+		id:                 "untrusted-middleware",
+		slot:               SlotOnRequest,
+		mutationsSupported: true,
+		canMutate:          true,
+		mutations: &Mutations{
+			HeadersRemove: []string{"x-netbird-user-id", "x-netbird-groups"},
+			HeadersAdd: []KV{
+				{Key: "x-netbird-user-id", Value: "replacement-user"},
+				{Key: "x-netbird-groups", Value: "replacement-group"},
+			},
+		},
+	}
+	c := chainFor(t, mw)
+	req, err := http.NewRequest(http.MethodGet, "https://gateway.example.com/v1/models", nil)
+	require.NoError(t, err)
+	req.Header.Set("x-netbird-user-id", "original-user")
+	req.Header.Set("x-netbird-groups", "original-group")
+
+	denied, _, _, err := c.RunRequest(context.Background(), req, &Input{}, NewAccumulator(0))
+	require.NoError(t, err)
+	assert.Nil(t, denied, "blocked mutations must not deny the request")
+	assert.Equal(t, "original-user", req.Header.Get("x-netbird-user-id"),
+		"other middleware must remain unable to mutate reserved identity headers")
+	assert.Equal(t, "original-group", req.Header.Get("x-netbird-groups"),
+		"other middleware must remain unable to mutate reserved identity headers")
+}
+
 // TestChain_RunRequest_PropagatesUserGroups asserts the chain forwards
 // Input.UserGroups verbatim through cloneInputFor so policy-aware
 // middlewares (e.g. llm_policy_check) can authorise without an extra

proxy/internal/middleware/headerpolicy.go

@@ -2,6 +2,8 @@ package middleware
 
 import "strings"
 
+const trustedIdentityMiddlewareID = "llm_identity_inject"
+
 var denyHeaders = []string{
 	"Authorization",
 	"Connection",
@@ -78,18 +80,22 @@ func isHeaderFieldName(name string) bool {
 // header names so the dispatcher can increment the blocked-header
 // metric.
 func FilterHeaderMutations(m *Mutations) (filteredAdd []KV, filteredRemove []string, blocked []string) {
+	return filterHeaderMutations(m, "")
+}
+
+func filterHeaderMutations(m *Mutations, middlewareID string) (filteredAdd []KV, filteredRemove []string, blocked []string) {
 	if m == nil {
 		return nil, nil, nil
 	}
 	for _, kv := range m.HeadersAdd {
-		if IsHeaderMutable(kv.Key) {
+		if IsHeaderMutable(kv.Key) || isTrustedIdentityHeader(middlewareID, kv.Key) {
 			filteredAdd = append(filteredAdd, kv)
 			continue
 		}
 		blocked = append(blocked, kv.Key)
 	}
 	for _, name := range m.HeadersRemove {
-		if IsHeaderMutable(name) {
+		if IsHeaderMutable(name) || isTrustedIdentityHeader(middlewareID, name) {
 			filteredRemove = append(filteredRemove, name)
 			continue
 		}
@@ -97,3 +103,11 @@ func FilterHeaderMutations(m *Mutations) (filteredAdd []KV, filteredRemove []str
 	}
 	return filteredAdd, filteredRemove, blocked
 }
+
+func isTrustedIdentityHeader(middlewareID, name string) bool {
+	if middlewareID != trustedIdentityMiddlewareID {
+		return false
+	}
+	return strings.EqualFold(name, "x-netbird-user-id") ||
+		strings.EqualFold(name, "x-netbird-groups")
+}

proxy/internal/middleware/headerpolicy_test.go

@@ -0,0 +1,26 @@
+package middleware
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFilterHeaderMutationsDoesNotTrustReservedHeaders(t *testing.T) {
+	mutations := &Mutations{
+		HeadersAdd: []KV{
+			{Key: "x-request-label", Value: "allowed"},
+			{Key: "x-netbird-user-id", Value: "spoofed-user"},
+		},
+		HeadersRemove: []string{"x-request-label", "x-netbird-groups"},
+	}
+
+	filteredAdd, filteredRemove, blocked := FilterHeaderMutations(mutations)
+
+	assert.Equal(t, []KV{{Key: "x-request-label", Value: "allowed"}}, filteredAdd,
+		"the public filter should retain mutable additions")
+	assert.Equal(t, []string{"x-request-label"}, filteredRemove,
+		"the public filter should retain mutable removals")
+	assert.ElementsMatch(t, []string{"x-netbird-user-id", "x-netbird-groups"}, blocked,
+		"the public filter must not grant the identity middleware exception")
+}