From 4ca47d191850a0b3646b957f76814fa0fbb9c1ca Mon Sep 17 00:00:00 2001
From: Markov <markov@uix.su>
Date: Mon, 23 Feb 2026 10:19:10 +0100
Subject: [PATCH] OAuth stealth mode: Claude Code headers + tool name mapping

---
 picogent/providers/anthropic.py | 37 +++++++++++++++++++++++++++------
 1 file changed, 31 insertions(+), 6 deletions(-)

diff --git a/picogent/providers/anthropic.py b/picogent/providers/anthropic.py
index 3b75bd8..a12ac9a 100644
--- a/picogent/providers/anthropic.py
+++ b/picogent/providers/anthropic.py
@@ -10,6 +10,13 @@ from .base import BaseProvider
 
 logger = logging.getLogger("picogent.anthropic")
 
+# Claude Code tool name mapping (lowercase -> CC canonical)
+CLAUDE_CODE_TOOLS = {
+    "read": "Read", "write": "Write", "edit": "Edit", "bash": "Bash",
+    "grep": "Grep", "glob": "Glob",
+}
+CC_TOOL_REVERSE = {v.lower(): k for k, v in CLAUDE_CODE_TOOLS.items()}
+
 
 class AnthropicProvider(BaseProvider):
     """Anthropic Claude provider using direct API calls"""
@@ -18,6 +25,7 @@ class AnthropicProvider(BaseProvider):
         super().__init__(api_key, model)
         self.base_url = "https://api.anthropic.com/v1"
         self.anthropic_version = "2023-06-01"
+        self.is_oauth = api_key.startswith("sk-ant-oat")
     
     async def generate_response(
         self, 
@@ -28,12 +36,19 @@ class AnthropicProvider(BaseProvider):
     ) -> Dict[str, Any]:
         """Generate response using Anthropic Messages API"""
         
-        # OAuth tokens (sk-ant-oat*) use Bearer auth, regular keys use x-api-key
-        if self.api_key.startswith("sk-ant-oat"):
+        is_oauth = self.api_key.startswith("sk-ant-oat")
+        
+        if is_oauth:
+            # OAuth tokens: Bearer auth + Claude Code stealth headers
             headers = {
                 "Content-Type": "application/json",
+                "Accept": "application/json",
                 "Authorization": f"Bearer {self.api_key}",
-                "anthropic-version": self.anthropic_version
+                "anthropic-version": self.anthropic_version,
+                "anthropic-beta": "claude-code-20250219,oauth-2025-04-20",
+                "anthropic-dangerous-direct-browser-access": "true",
+                "User-Agent": "claude-cli/2.1.2 (external, cli)",
+                "x-app": "cli",
             }
         else:
             headers = {
@@ -49,9 +64,15 @@ class AnthropicProvider(BaseProvider):
             "messages": messages
         }
         
-        # Add tools if provided
+        # Add tools if provided (rename for OAuth/Claude Code stealth)
         if tools:
-            payload["tools"] = tools
+            if is_oauth:
+                payload["tools"] = [
+                    {**t, "name": CLAUDE_CODE_TOOLS.get(t["name"], t["name"])}
+                    for t in tools
+                ]
+            else:
+                payload["tools"] = tools
         
         logger.info(f"POST {self.base_url}/messages | model={self.model} | key={self.api_key[:8]}...{self.api_key[-4:]} (len={len(self.api_key)})")
         logger.debug(f"Headers: x-api-key={self.api_key[:8]}..., anthropic-version={self.anthropic_version}")
@@ -84,9 +105,13 @@ class AnthropicProvider(BaseProvider):
                 if block.get("type") == "text":
                     text_parts.append(block.get("text", ""))
                 elif block.get("type") == "tool_use":
+                    name = block.get("name")
+                    # Map Claude Code names back to original
+                    if self.is_oauth:
+                        name = CC_TOOL_REVERSE.get(name.lower(), name)
                     tool_calls.append({
                         "id": block.get("id"),
-                        "name": block.get("name"),
+                        "name": name,
                         "input": block.get("input", {})
                     })