implemented stateless ant/oai messages/responses apis

README.md

@@ -4,10 +4,13 @@ Dynagate is a lightweight, high-performance LLM gateway written in Go that acts
 
 ## Features
 
-1. **OpenAI-compatible endpoints**:
+1. **Multi-API Protocol Endpoints (Stateless)**:
    - `/v1/models` (GET): Dynamically lists unique active model IDs.
    - `/v1/chat/completions` (POST): Proxies non-streaming and streaming (`text/event-stream`) completions.
+   - `/v1/responses` (POST): Stateless-style OpenAI Responses API endpoint (automatically routed to upstream chat completions endpoints).
+   - `/v1/messages` (POST): Anthropic-compatible Messages API endpoint (automatically routed to upstream chat completions endpoints).
    - `/v1/images/generations` (POST): Proxies image generation requests.
+   > **Note**: Dynagate operates in a completely stateless manner across all API formats (`/v1/chat/completions`, `/v1/responses`, `/v1/messages`). Dynagate does not store or persist server-side conversation state. Clients must include the full conversation history in each request for multi-turn dialogues.
 
 2. **Zero-downtime live-reloading**:
    - Watches `models.csv` (overridable via command-line flags) continuously using a background thread and automatically reloads configuration updates without dropping active connections.
@@ -112,6 +115,15 @@ The gateway maps columns dynamically by looking at the header row. If no header
 - **`"-blank-"`**: The gateway will attach exactly `Authorization: Bearer` without any key appended.
 - **Any other string**: The gateway will attach `Authorization: Bearer <key>`.
 
+### Stateless Operation & Multi-Turn Conversations
+
+Dynagate is designed as a lightweight, zero-state proxy gateway. All supported request formats (`/v1/chat/completions`, `/v1/responses`, `/v1/messages`) are processed statelessly without storing session context or conversation state on disk or in memory. 
+
+To maintain context in multi-turn conversations, clients **must include the entire conversation history** in every request payload:
+- **OpenAI Chat Completions (`/v1/chat/completions`)**: Pass the full array of system, user, and assistant messages in `messages`.
+- **OpenAI Responses API (`/v1/responses`)**: Pass previous conversation turns in `input` (or `messages`) along with `instructions`.
+- **Anthropic Messages API (`/v1/messages`)**: Pass the full history of user and assistant messages in `messages` along with `system`.
+
 ### Manual testing with curl
 
 #### 1. Model listing (authenticated)
@@ -142,6 +154,30 @@ curl -i -X POST http://localhost:8080/v1/chat/completions \
   }'
 ```
 
+#### 4. OpenAI-compatible Responses API (`/v1/responses`)
+```bash
+curl -i -X POST http://localhost:8080/v1/responses \
+  -H "Authorization: Bearer my-secure-gateway-token" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "model": "gpt-4o",
+    "instructions": "Be concise",
+    "input": "Explain relativity in one sentence"
+  }'
+```
+
+#### 5. Anthropic-compatible Messages API (`/v1/messages`)
+```bash
+curl -i -X POST http://localhost:8080/v1/messages \
+  -H "Authorization: Bearer my-secure-gateway-token" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "model": "claude-3-5-sonnet",
+    "system": "You are a helpful assistant",
+    "messages": [{"role": "user", "content": "Hello world"}]
+  }'
+```
+
 ## Troubleshooting
 
 ### Dynamic loading failures