curl -X POST 'https://api.openai.com/v1/responses/input_tokens' \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{}'

# POST /responses/input_tokens (OpenAI API)
Base URL: https://api.openai.com/v1
Auth: Authorization; OpenAI API key; required.
Request formats: application/json.
Last verified: 2026-10-20

> Get input token counts

## Critical Gotchas
* The Responses API is the primary interface for new text and tool workflows; Chat Completions remains a separate compatibility API.
* Audio transcription uploads use multipart form data rather than a JSON request body.

## cURL
curl -X POST 'https://api.openai.com/v1/responses/input_tokens' \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{}'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| model | body | string | No | Model ID used to generate the response, like `gpt-4o` or `o3`. OpenAI offers... |
| input | body | string | No | Text, image, or file inputs to the model, used to generate a response |
| previous_response_id | body | string | No | The unique ID of the previous response to the model. Use this to create multi... |
| tools | body | object[] | No | An array of tools the model may call while generating a response. You can spe... |
| text | body | object | No | Configuration options for a text response from the model. Can be plain text o... |
| reasoning | body | object | No | Configuration options for [reasoning models](https://developers.openai.com/ap... |
| truncation | body | string | No | Request body field truncation. |
| instructions | body | string | No | A system (or developer) message inserted into the model's context. When used... |
Other params: personality, conversation, tool_choice, parallel_tool_calls

## Response example
{"object":"response.input_tokens","input_tokens":123}

---
Need an API key? Get one at https://platform.openai.com/api-keys

POST

POST /responses/input_tokens — OpenAI API

OpenAI API key (required); https://api.openai.com/v1

OpenAI API

Get input token counts

Base URL: https://api.openai.com/v1
Auth: Authorization: Bearer <OPENAI_API_KEY>
Last verified: 2026-10-20 · upstream hash matched

Actions Try in browser→

Agents: curl -H "Accept: text/markdown" this URL
→ 384 tokens · Vary: Accept

Critical gotchas

The Responses API is the primary interface for new text and tool workflows; Chat Completions remains a separate compatibility API.

Audio transcription uploads use multipart form data rather than a JSON request body.

cURL

curl -X POST 'https://api.openai.com/v1/responses/input_tokens' \  -H "Authorization: Bearer $OPENAI_API_KEY" \  -H 'Content-Type: application/json' \  -d '{}'

Parameters

Name	In	Type	Required	Description
model	body	string	No	Model ID used to generate the response, like `gpt-4o` or `o3`. OpenAI offers a wide range of models with different capabilities, performance characteristics, and price points. Refer to the [model guide](https://developers.openai.com/api/docs/models) to browse and compare available models.
input	body	string	No	Text, image, or file inputs to the model, used to generate a response
previous_response_id	body	string	No	The unique ID of the previous response to the model. Use this to create multi-turn conversations. Learn more about [conversation state](https://developers.openai.com/api/docs/guides/conversation-state). Cannot be used in conjunction with `conversation`.
tools	body	object[]	No	An array of tools the model may call while generating a response. You can specify which tool to use by setting the `tool_choice` parameter.
text	body	object	No	Configuration options for a text response from the model. Can be plain text or structured JSON data. Learn more: - [Text inputs and outputs](https://developers.openai.com/api/docs/guides/text) - [Structured Outputs](https://developers.openai.com/api/docs/guides/structured-outputs)
reasoning	body	object	No	Configuration options for [reasoning models](https://developers.openai.com/api/docs/guides/reasoning).
truncation	body	string	No	Request body field truncation.
instructions	body	string	No	A system (or developer) message inserted into the model's context. When used along with `previous_response_id`, the instructions from a previous response will not be carried over to the next response. This makes it simple to swap out system (or developer) messages in new responses.
personality	body	string	No	Request body field personality.
conversation	body	string	No	The conversation that this response belongs to. Items from this conversation are prepended to `input_items` for this response request. Input items and output items from this response are automatically added to this conversation after this response completes.
tool_choice	body	string	No	How the model should select which tool (or tools) to use when generating a response. See the `tools` parameter to see how to specify which tools the model can call.
parallel_tool_calls	body	boolean	No	Whether to allow the model to run tool calls in parallel.

Response 200 OK

{
  "object": "response.input_tokens",
  "input_tokens": 123
}

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