feat: add anthropic-messages protocol for native Anthropic Messages API support Fixes #269

README.md

@@ -1097,6 +1097,26 @@ This design also enables **multi-agent support** with flexible provider selectio
 
 > Run `picoclaw auth login --provider anthropic` to paste your API token.
 
+**Anthropic Messages API (native format)**
+
+For direct Anthropic API access or custom endpoints that only support Anthropic's native message format:
+
+```json
+{
+  "model_name": "claude-opus-4-6",
+  "model": "anthropic-messages/claude-opus-4-6",
+  "api_key": "sk-ant-your-key",
+  "api_base": "https://api.anthropic.com"
+}
+```
+
+> Use `anthropic-messages` protocol when:
+> - Using third-party proxies that only support Anthropic's native `/v1/messages` endpoint (not OpenAI-compatible `/v1/chat/completions`)
+> - Connecting to services like MiniMax, Synthetic that require Anthropic's native message format
+> - The existing `anthropic` protocol returns 404 errors (indicating the endpoint doesn't support OpenAI-compatible format)
+>
+> **Note:** The `anthropic` protocol uses OpenAI-compatible format (`/v1/chat/completions`), while `anthropic-messages` uses Anthropic's native format (`/v1/messages`). Choose based on your endpoint's supported format.
+
 **Ollama (local)**
 
 ```json

README.zh.md

@@ -593,6 +593,26 @@ Agent 读取 HEARTBEAT.md
 
 > 运行 `picoclaw auth login --provider anthropic` 来设置 OAuth 凭证。
 
+**Anthropic Messages API（原生格式）**
+
+用于直接访问 Anthropic API 或仅支持 Anthropic 原生消息格式的自定义端点：
+
+```json
+{
+  "model_name": "claude-opus-4-6",
+  "model": "anthropic-messages/claude-opus-4-6",
+  "api_key": "sk-ant-your-key",
+  "api_base": "https://api.anthropic.com"
+}
+```
+
+> 使用 `anthropic-messages` 协议的场景：
+> - 使用仅支持 Anthropic 原生 `/v1/messages` 端点的第三方代理（不支持 OpenAI 兼容的 `/v1/chat/completions`）
+> - 连接到 MiniMax、Synthetic 等需要 Anthropic 原生消息格式的服务
+> - 现有的 `anthropic` 协议返回 404 错误（说明端点不支持 OpenAI 兼容格式）
+>
+> **注意：** `anthropic` 协议使用 OpenAI 兼容格式（`/v1/chat/completions`），而 `anthropic-messages` 使用 Anthropic 原生格式（`/v1/messages`）。请根据端点支持的格式选择。
+
 **Ollama (本地)**
 
 ```json

config/config.example.json

@@ -25,6 +25,13 @@
       "api_base": "https://api.anthropic.com/v1",
       "thinking_level": "high"
     },
+    {
+      "_comment": "Anthropic Messages API - use native format for direct Anthropic API access",
+      "model_name": "claude-opus-4-6",
+      "model": "anthropic-messages/claude-opus-4-6",
+      "api_key": "sk-ant-your-key",
+      "api_base": "https://api.anthropic.com"
+    },
     {
       "model_name": "gemini",
       "model": "antigravity/gemini-2.0-flash",