Count input tokens¶

Count input tokens for a Messages request without generating a reply.

POST https://token.moi.matrixorigin.cn/v1/messages/count_tokens

Before you begin¶

Prepare a personal access token or service account API key for Genesis. See Access credentials for credential selection and permissions.
Use List callable models to select a model that supports Messages.

Request body¶

Replace $GENESIS_ACCESS_TOKEN and $MODEL_ID with your credential and the selected model ID.

Request example

curl -X POST \
  "https://token.moi.matrixorigin.cn/v1/messages/count_tokens" \
  -H "Authorization: Bearer $GENESIS_ACCESS_TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "'"$MODEL_ID"'",
  "messages": [
    {
      "role": "user",
      "content": [
        {
          "type": "text",
          "text": "Reply with OK."
        }
      ]
    }
  ]
}'

Parameters

The fields below cover text messages; a count request does not require an output token limit.

Parameter	Type	Required	Description
`model`	string	Yes	Selected model ID from `data[].id` in the model list.
`messages`	array of object	Yes	Nonempty messages in conversation order.
`messages[].role`	string	Yes	Message role: `user` or `assistant` for text conversations.
`messages[].content`	string or array of object	Yes	Text or text blocks.
`messages[].content[].type`	string	Required for a text block	Use `text` for a text block.
`messages[].content[].text`	string	Required for a text block	Nonempty text content.

Successful response¶

A successful request returns the number of input tokens in the messages.

Response example

{
  "input_tokens": 12
}

Fields

Field	Type	Description
`input_tokens`	integer	Nonnegative input token count.

Error response¶

A missing model ID returns HTTP 400. Supply the model ID before sending the request again.

Response example

{
  "error": {
    "message": "missing required parameter: model",
    "type": "invalid_request",
    "code": "invalid_request"
  }
}

Fields

Field	Type	Description
`error`	object	Error details.
`error.message`	string	Error description; the example indicates a missing model ID.
`error.type`	string	Error type; may be omitted by a model service.
`error.code`	string or null	Error code; may be omitted by a model service.

Next steps¶

After checking the input length, use the same model and messages to Create a Message.

Last updated on Sep 15, 2026