Skip to main content
April 2026 Mavera has migrated from the OpenAI Chat Completions format to the OpenAI Responses API format. This is the same API shape used by OpenAI’s latest SDKs and brings a cleaner interface, flat tool definitions, and named streaming events.

​
What Changed

AreaChat Completions (before)Responses API (after)
EndpointPOST /api/v1/chat/completionsPOST /api/v1/responses
SDK methodclient.chat.completions.create()client.responses.create()
Input formatmessages: [{role, content}]input: "string" or input: [{role, content}]
System messagesPart of messages arrayinstructions parameter
Response outputresponse.choices[0].message.contentresponse.output[0].content[0].text
Streamingstream=True flagclient.responses.stream() with named events
Tool formatNested {function: {name, ...}}Flat {name, description, parameters}
Tool results{role: "tool", tool_call_id}{type: "function_call_output", call_id}
Structured outputresponse_formattext: {format: {...}} via extra_body
Token fieldsprompt_tokens / completion_tokensinput_tokens / output_tokens
Finish signalfinish_reason: "stop"status: "completed"

​
Why

The Responses API is OpenAI’s latest standard and provides several improvements:
  • Simpler input — pass a plain string for single-turn queries instead of wrapping everything in a messages array
  • Dedicated instructions parameter — cleanly separates system-level guidance from user input, and appends to the persona’s built-in prompt
  • Flat tool format — no more nested function wrapper; tool properties are top-level
  • Named SSE events — response.created, response.output_text.delta, response.completed make stream parsing more explicit
  • Cleaner response shape — no choices array; output items are typed (message, function_call)

​
Migration Path

We’ve published a detailed migration guide that covers every change with before/after code examples in Python, JavaScript, and cURL.

Migration Guide

Step-by-step instructions to migrate from Chat Completions to the Responses API

​
What’s New

​
instructions Parameter

System messages are replaced by the instructions parameter. Instructions are appended to the persona’s built-in system prompt, so you get persona context plus your task-specific guidance without message array management. 
response = client.responses.create(
    model="mavera-1",
    input="Analyze brand loyalty trends.",
    instructions="You are a market research analyst. Focus on Gen Z.",
    extra_body={"persona_id": "YOUR_PERSONA_ID"},
)

​
Flat Tool Format

Tool definitions no longer require a function wrapper. Properties are top-level: 
tools = [
    {
        "type": "function",
        "name": "get_weather",
        "description": "Get the current weather",
        "parameters": {
            "type": "object",
            "properties": {"location": {"type": "string"}},
            "required": ["location"]
        }
    }
]

​
Named SSE Events

Streaming now uses named event types instead of generic data chunks:
EventDescription
response.createdResponse object created
response.output_text.deltaA text chunk — access via event.delta
response.completedResponse is fully complete
with client.responses.stream(
    model="mavera-1",
    input="Write a product description",
    extra_body={"persona_id": "YOUR_PERSONA_ID"},
) as stream:
    for event in stream:
        if event.type == "response.output_text.delta":
            print(event.delta, end="", flush=True)

​
Backward Compatibility

The Chat Completions endpoint (/api/v1/chat/completions) remains available during the transition period. All new features and documentation target the Responses API exclusively.