Chat Completions¶

Send messages to a Genesis model that supports Chat Completions and return generated content.

POST https://token.moi.matrixorigin.cn/v1/chat/completions

Before you call¶

Prepare credentials with Genesis access and obtain a model ID from List models. Confirm that the selected model supports Chat Completions.

Request body¶

Replace $GENESIS_ACCESS_TOKEN with an access token or service-account API key, and $MODEL_ID with the model ID to call.

Request example

curl -X POST \
  "https://token.moi.matrixorigin.cn/v1/chat/completions" \
  -H "Authorization: Bearer $GENESIS_ACCESS_TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "'"$MODEL_ID"'",
    "messages": [{"role": "user", "content": "Explain the purpose of a database transaction in one sentence."}],
    "max_tokens": 128
  }'

Parameter description

Parameters

Field	Type	Required	Description
`model`	string	Yes	Chat Completions model ID to call.
`messages`	array of object	Yes	Ordered list of messages to submit.
`max_tokens`	integer	No	Maximum output tokens for this generation; use only values supported by the selected model.
`temperature`	number	No	Sampling temperature; set only when the selected model supports it.
`stream`	boolean	No	Set to `true` to request streaming output; see Streaming response.

Message item

The following table expands each item in the example messages array.

Field	Type	Required	Description
`role`	string	Yes	Message role.
`content`	string	Yes	Text content of the message.

Successful response¶

The service returns a model-generated message.

Response example

{
  "id": "<COMPLETION_ID>",
  "object": "chat.completion",
  "model": "<MODEL_ID>",
  "choices": [
    {
      "index": 0,
      "message": {"role": "assistant", "content": "A transaction executes a group of operations as a whole to preserve data consistency."},
      "finish_reason": "stop"
    }
  ]
}

Field description

Common fields

Field	Type	Description
`id`	string	Identifier for this Completion.
`object`	string	Response object type; the example is `chat.completion`.
`model`	string	Model ID that processed the request.
`choices`	array of object	List of generated results.

Result item

The following table expands each item in the example choices array.

Field	Type	Description
`index`	integer	Position of this result in the list.
`message`	object	Assistant message.
`finish_reason`	string	Reason the current generation ended.

Message object

The following table expands the example choices[].message object.

Field	Type	Description
`role`	string	Message role.
`content`	string	Text generated by the assistant.

Streaming response¶

Set stream to true and send Accept: text/event-stream to request streaming output. The service returns text/event-stream; continue reading incremental content from events until data: [DONE] arrives. An error before the stream is established is a JSON error object with the same shape as Error response.

Call example

curl -N -X POST \
  "https://token.moi.matrixorigin.cn/v1/chat/completions" \
  -H "Authorization: Bearer $GENESIS_ACCESS_TOKEN" \
  -H 'Content-Type: application/json' \
  -H 'Accept: text/event-stream' \
  -d '{"model":"'"$MODEL_ID"'","messages":[{"role":"user","content":"Explain the purpose of a primary key in one sentence."}],"stream":true}'

Response example

data: {"object":"chat.completion.chunk","choices":[{"delta":{"content":"A primary key"}}]}

data: {"object":"chat.completion.chunk","choices":[{"delta":{"content":" uniquely identifies each row in a table."}}]}

data: [DONE]

Field description

Common fields

Field	Type	Description
`object`	string	Event object type; the example is `chat.completion.chunk`.
`choices`	array of object	Incremental results in the current event.
`[DONE]`	event marker	Normal completion marker; mark the result complete only after receiving it.

Result item

Field	Type	Description
`delta`	object	Incremental object.

Incremental content

Field	Type	Description
`content`	string	Append it to the current text when present.

Error response¶

Response example

{"error":{"message":"<human-readable error message>","type":"<error type; may be omitted>","code":"<error code; may be omitted>"}}

Field description

Common fields

Field	Type	Description
`error`	object	Error object.

Error object

Field	Type	Description
`message`	string	Human-readable error message.
`type`	string	Error category returned by the model service; it may be omitted.
`code`	string or null	Error code returned by the model service; it may be omitted.

Next steps¶

For streaming reads, see Streaming response above. For other request shapes, see Responses and Messages (Anthropic).

Last updated on Sep 3, 2026