LLM requests name the program in User-Agent

cmd/agent/main.go

@@ -72,6 +72,7 @@ func main() {
 	// sandbox, it re-runs THIS binary, which self-restricts and execs the real
 	// command. Must run first; a normal launch falls straight through.
 	sandbox.MaybeExecConfined()
+	llm.UserAgent = userAgent()
 	var (
 		workspace       string
 		doInit          bool

internal/llm/client.go

@@ -183,6 +183,18 @@ func (c *deadlineConn) Read(b []byte) (int, error) {
 // transport DOES bound the connect/handshake/response-header phases so a dead
 // connection (e.g. after the laptop sleeps) can't wedge a request forever —
 // short of that, a stuck socket read ignores context cancellation.
+// UserAgent names this program on every request to the model server, so a
+// proxy in front of it (LLMTray, a gateway) can tell it from any other Go
+// client — they all said "Go-http-client/1.1". Set once at startup; empty
+// leaves Go's default.
+var UserAgent string
+
+func setUserAgent(req *http.Request) {
+	if UserAgent != "" {
+		req.Header.Set("User-Agent", UserAgent)
+	}
+}
+
 func NewOpenAIClient(c config.LLM) *OpenAIClient {
 	idle := 90 * time.Second
 	if c.IdleTimeoutSeconds > 0 {
@@ -567,6 +579,7 @@ func (c *OpenAIClient) send(ctx context.Context, buf []byte, reqCompl *int) (Mes
 	}
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("Accept", "text/event-stream")
+	setUserAgent(req)
 	if strings.Contains(c.baseURL, "openrouter.ai") {
 		// OpenRouter uses these to attribute traffic to the app (rankings, some
 		// free-tier access). Harmless elsewhere, so only set for OpenRouter.

internal/llm/detect.go

@@ -25,6 +25,7 @@ func ListModels(ctx context.Context, baseURL, apiKey string, hc *http.Client) ([
 	if err != nil {
 		return nil, err
 	}
+	setUserAgent(req)
 	if apiKey != "" {
 		req.Header.Set("Authorization", "Bearer "+apiKey)
 	}
@@ -70,6 +71,7 @@ func DetectModelContext(ctx context.Context, baseURL, apiKey, model string, hc *
 	if err != nil {
 		return 0
 	}
+	setUserAgent(req)
 	if apiKey != "" {
 		req.Header.Set("Authorization", "Bearer "+apiKey)
 	}
@@ -123,6 +125,7 @@ func ListLMStudioModels(ctx context.Context, baseURL string, hc *http.Client) ([
 	if err != nil {
 		return nil, err
 	}
+	setUserAgent(req)
 	resp, err := hc.Do(req)
 	if err != nil {
 		return nil, err
@@ -154,6 +157,7 @@ func DetectContextWindow(ctx context.Context, baseURL, model string, hc *http.Cl
 	if err != nil {
 		return 0
 	}
+	setUserAgent(req)
 	resp, err := hc.Do(req)
 	if err != nil {
 		return 0

internal/llm/useragent_test.go

@@ -0,0 +1,63 @@
+package llm
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+
+	"github.com/ipsupport-llc/ipsupport-code/internal/config"
+)
+
+// Every request to the model server names this program: a proxy in front of
+// it saw only "Go-http-client/1.1", the same as any other Go tool.
+func TestEveryModelRequestCarriesTheUserAgent(t *testing.T) {
+	defer func(ua string) { UserAgent = ua }(UserAgent)
+	UserAgent = "ipsupport-code/9.9.9"
+
+	var mu sync.Mutex
+	var seen []string // "path user-agent", one per request
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		mu.Lock()
+		seen = append(seen, r.URL.Path+" "+r.Header.Get("User-Agent"))
+		mu.Unlock()
+		switch r.URL.Path {
+		case "/v1/chat/completions":
+			io.WriteString(w, `{"choices":[{"message":{"role":"assistant","content":"hi"},"finish_reason":"stop"}]}`)
+		default:
+			io.WriteString(w, `{"data":[{"id":"m","state":"loaded","loaded_context_length":8192}]}`)
+		}
+	}))
+	defer srv.Close()
+
+	ctx := context.Background()
+	base := srv.URL + "/v1"
+	calls := map[string]func(){
+		"ListModels":          func() { _, _ = ListModels(ctx, base, "", srv.Client()) },
+		"DetectModelContext":  func() { _ = DetectModelContext(ctx, base, "", "m", srv.Client()) },
+		"ListLMStudioModels":  func() { _, _ = ListLMStudioModels(ctx, base, srv.Client()) },
+		"DetectContextWindow": func() { _ = DetectContextWindow(ctx, base, "m", srv.Client()) },
+		"Chat": func() {
+			_, _ = NewOpenAIClient(config.LLM{BaseURL: base, Model: "m"}).Chat(ctx, []Message{User("hi")}, nil)
+		},
+	}
+	for name, call := range calls {
+		mu.Lock()
+		seen = nil
+		mu.Unlock()
+		call()
+		mu.Lock()
+		if len(seen) == 0 {
+			t.Errorf("%s made no request", name)
+		}
+		for _, s := range seen {
+			if !strings.HasSuffix(s, " "+UserAgent) {
+				t.Errorf("%s: request %q, want User-Agent %q", name, s, UserAgent)
+			}
+		}
+		mu.Unlock()
+	}
+}