more oc fixes

main.go

@@ -8,6 +8,7 @@ import (
   "bytes"
   "context"
   "crypto/md5"
+  "crypto/rand"
   "encoding/hex"
   "encoding/json"
   "errors"
@@ -87,6 +88,8 @@ var llmTransport = &http.Transport{
 
 var defCfg = Cfg{"https://api.kilo.ai/api/openrouter", "openrouter/free", "-", 0.7, 300, 120, 1000, true, "auto", 262144, 15000, map[string]string{"reasoning_effort": "high"}}
 const opencodeAgentVersion = "opencode/1.18.31"
+const opencodeProviderUA = "ai-sdk/provider-utils/4.0.23 runtime/bun/1.3.14"
+const opencodeIDAlphabet = "0123456789ABCDEFGHJKMNPQRSTVWXYZ"
 
 func atoiD(s string, d int) int {
   if v, e := strconv.Atoi(strings.TrimSpace(s)); e == nil {
@@ -105,12 +108,7 @@ func queryModelsContextWindow(cfg *Cfg) int {
   }
   req, err := http.NewRequest("GET", strings.TrimRight(cfg.Endpoint, "/")+"/models", nil)
   if err != nil { return 0 }
-  req.Header.Set("User-Agent", opencodeAgentVersion)
-  req.Header.Set("X-Session-Id", projectID())
-  req.Header.Set("x-opencode-project", projectID())
-  req.Header.Set("x-opencode-client", "cli")
-  req.Header.Set("x-opencode-session", opencodeSessionID())
-  if cfg.APIKey != "" && cfg.APIKey != "-" { req.Header.Set("Authorization", "Bearer "+cfg.APIKey) }
+  applyLLMHeaders(req, cfg, ocRequestID())
   resp, err := client.Do(req)
   if err != nil || resp.StatusCode >= 400 { return 0 }
   defer resp.Body.Close()
@@ -181,12 +179,7 @@ func listModels(cfg *Cfg) (string, error) {
   }
   req, err := http.NewRequest("GET", strings.TrimRight(cfg.Endpoint, "/")+"/models", nil)
   if err != nil { return "", err }
-  req.Header.Set("User-Agent", opencodeAgentVersion)
-  req.Header.Set("X-Session-Id", projectID())
-  req.Header.Set("x-opencode-project", projectID())
-  req.Header.Set("x-opencode-client", "cli")
-  req.Header.Set("x-opencode-session", opencodeSessionID())
-  if cfg.APIKey != "" && cfg.APIKey != "-" { req.Header.Set("Authorization", "Bearer "+cfg.APIKey) }
+  applyLLMHeaders(req, cfg, ocRequestID())
   resp, err := client.Do(req)
   if err != nil { return "", err }
   defer resp.Body.Close()
@@ -1052,6 +1045,7 @@ func llm(ctx context.Context, cfg *Cfg, msgs []Message, tools []map[string]any)
   pend := c("...requesting...", 1, 2)
   var resp *http.Response
   var err error
+  reqID := ocRequestID()
   for i := 0; i <= len(fib); i++ {
     if err := ctx.Err(); err != nil {
       if COL { fmt.Print("\r\033[K") }
@@ -1060,12 +1054,7 @@ func llm(ctx context.Context, cfg *Cfg, msgs []Message, tools []map[string]any)
     if COL { fmt.Print("\r" + pend) } else { fmt.Println(pend) }
     req, _ := http.NewRequestWithContext(ctx, "POST", strings.TrimRight(cfg.Endpoint, "/")+"/chat/completions", bytes.NewReader(body))
     req.Header.Set("Content-Type", "application/json")
-    req.Header.Set("User-Agent", opencodeAgentVersion)
-    req.Header.Set("X-Session-Id", projectID())
-    req.Header.Set("x-opencode-project", projectID())
-    req.Header.Set("x-opencode-client", "cli")
-    req.Header.Set("x-opencode-session", opencodeSessionID())
-    if cfg.APIKey != "" && cfg.APIKey != "-" { req.Header.Set("Authorization", "Bearer "+cfg.APIKey) }
+    applyLLMHeaders(req, cfg, reqID)
     resp, err = client.Do(req)
     var is4xxClientErr bool
     if err == nil && resp.StatusCode >= 400 {
@@ -1694,6 +1683,57 @@ func opencodeSessionID() string {
   return "ses_" + pid
 }
 
+// isOpencodeEndpoint reports whether the endpoint belongs to OpenCode Zen and
+// therefore expects the x-opencode-* request headers.
+func isOpencodeEndpoint(endpoint string) bool {
+  u, err := url.Parse(strings.TrimSpace(endpoint))
+  if err != nil || u.Hostname() == "" {
+    return strings.Contains(strings.ToLower(endpoint), "opencode.ai")
+  }
+  h := strings.ToLower(u.Hostname())
+  return h == "opencode.ai" || strings.HasSuffix(h, ".opencode.ai")
+}
+
+// ocRequestID returns a fresh OpenCode-style message id (msg_ followed by 26
+// base32 characters) matching the ids sent in the x-opencode-request header.
+func ocRequestID() string {
+  buf := make([]byte, 26)
+  if _, err := rand.Read(buf); err != nil {
+    h := md5.Sum([]byte(fmt.Sprintf("%d-%d", time.Now().UnixNano(), os.Getpid())))
+    for i := range buf {
+      buf[i] = h[i%len(h)]
+    }
+  }
+  var b strings.Builder
+  b.WriteString("msg_")
+  for _, x := range buf {
+    b.WriteByte(opencodeIDAlphabet[int(x)&31])
+  }
+  return b.String()
+}
+
+// applyLLMHeaders sets the request headers appropriate for the configured
+// endpoint. OpenCode (Zen) endpoints receive the x-opencode-* family plus the
+// full provider User-Agent; all other endpoints keep the legacy
+// session-affinity headers. msgID is used for the x-opencode-request header.
+func applyLLMHeaders(req *http.Request, cfg *Cfg, msgID string) {
+  sid := opencodeSessionID()
+  if isOpencodeEndpoint(cfg.Endpoint) {
+    req.Header.Set("User-Agent", opencodeAgentVersion+" "+opencodeProviderUA)
+    req.Header.Set("x-opencode-client", "cli")
+    req.Header.Set("x-opencode-project", projectID())
+    req.Header.Set("x-opencode-session", sid)
+    req.Header.Set("x-opencode-request", msgID)
+  } else {
+    req.Header.Set("User-Agent", opencodeAgentVersion)
+    req.Header.Set("x-session-affinity", sid)
+    req.Header.Set("X-Session-Id", sid)
+  }
+  if cfg.APIKey != "" && cfg.APIKey != "-" {
+    req.Header.Set("Authorization", "Bearer "+cfg.APIKey)
+  }
+}
+
 func saveSession(msgs []Message, sid string) (string, string) {
   sid = strings.TrimSpace(sid)
   if sid == "" {