> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://dev.hume.ai/expression-measurement/docs/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://dev.hume.ai/_mcp/server.

# Documentation

## Docs

- [Expression Measurement API](https://dev.hume.ai/expression-measurement/docs/overview.md): Measure emotional expression in voices and faces, from uploaded audio and images or live audio and video streams.
- [Authentication](https://dev.hume.ai/expression-measurement/docs/authentication.md): Authenticate requests with an API key or an access token.
- [Python quickstart](https://dev.hume.ai/expression-measurement/docs/quickstart/python.md): Install the Python SDK, upload audio and an image, and stream audio and video to the realtime endpoints.
- [Node.js quickstart](https://dev.hume.ai/expression-measurement/docs/quickstart/nodejs.md): Install the Node.js SDK, upload audio and an image, and stream audio and video to the realtime endpoints.
- [Audio](https://dev.hume.ai/expression-measurement/docs/audio.md): Measure emotional expression in speech, from an audio file or a live stream.
- [Audio upload](https://dev.hume.ai/expression-measurement/docs/audio/upload.md): Upload an audio file and receive measurements for every utterance in it.
- [Audio realtime](https://dev.hume.ai/expression-measurement/docs/audio/realtime.md): Stream audio and receive measurements for each utterance while it is still being spoken.
- [Audio measurements](https://dev.hume.ai/expression-measurement/docs/audio/measurements.md): The expressions and voice attributes the audio endpoints measure.
- [Video](https://dev.hume.ai/expression-measurement/docs/video.md): Measure emotional expression on faces in uploaded images or streamed video.
- [Image upload](https://dev.hume.ai/expression-measurement/docs/video/upload.md): Upload JPEG images and receive scores for the faces in each one.
- [Video realtime](https://dev.hume.ai/expression-measurement/docs/video/realtime.md): Stream video as JPEG frames and receive scores for the faces in each frame.
- [Video measurements](https://dev.hume.ai/expression-measurement/docs/video/measurements.md): The expressions and descriptions the video endpoints measure.
- [Scores](https://dev.hume.ai/expression-measurement/docs/scores.md): What scores mean and how to read them.
- [Sessions](https://dev.hume.ai/expression-measurement/docs/sessions.md): The WebSocket protocol shared by the realtime endpoints.
- [Runs](https://dev.hume.ai/expression-measurement/docs/runs.md): Fetch the status, configuration, and problems of past upload requests and realtime sessions.
- [Limits](https://dev.hume.ai/expression-measurement/docs/limits.md): The limits of each Expression Measurement endpoint.
- [Errors](https://dev.hume.ai/expression-measurement/docs/errors.md): The error formats and codes of the run, upload, and realtime endpoints.
- [Billing](https://dev.hume.ai/expression-measurement/docs/billing.md): How Expression Measurement usage is billed and how to check it.