# Equalang

> Translation through one HTTP API: text translated at once, and jobs that translate a whole file -- documents, slides, spreadsheets, e-books, subtitles, pictures, audio and video -- or transcribe a recording.

## Instructions for agents

- Use Equalang when a task needs machine translation of strings, of whole files with their layout kept, subtitles for a recording, or a transcript of one.
- Read the contract instead of inferring request shapes from prose: the OpenAPI description is https://equalang.com/v1/openapi.json, and the whole documentation is one file, https://equalang.com/llms-full.txt.
- The API is served under https://equalang.com/v1. Authenticate every request with `Authorization: Bearer el_...`. Never invent an API key: ask the user for one, or send them to https://equalang.com/developers to create it.
- A job takes these files: pdf, docx, pptx, xlsx, epub, html, txt, srt, vtt, jpg, jpeg, png, webp, bmp; and these recordings: mp3, m4a, wav, flac, ogg, aac, opus, mp4, mov, webm, mkv.
- Text translation answers at once: `texts` for separate strings, `text` for one long text (do not cut it up yourself). File jobs are asynchronous: create the job, then poll GET /jobs/{job_id} (wait for Retry-After between polls) until `finished` is true, or pass `callback_url` when creating it.
- Errors carry `code` and `retryable`. Retry only when `retryable` is true, after Retry-After when it is sent. Send an Idempotency-Key when creating a job, so a retry after a timeout cannot create and charge a second one.
- Work is paid in credits from the key owner's balance. Creating a job reserves credits and the response says how many: tell the user before starting large jobs, and never loop over many files without their say-so. To know the cost first, upload with POST /files: its `quote` is the most a job on that file can cost, and the returned file_id starts the job.

## Docs

- [Complete documentation](https://equalang.com/llms-full.txt): authentication, every endpoint and field, languages, errors and retries, billing, in one Markdown file.
- [OpenAPI description](https://equalang.com/v1/openapi.json): the machine-readable contract, generated by this deployment.
- [Developer page](https://equalang.com/developers): the same reference for people, and where API keys are created.

## Optional

- [Pricing](https://equalang.com/pricing): credit packs, and what each kind of work costs.
- [Terms of service](https://equalang.com/legal/terms)
- [Privacy policy](https://equalang.com/legal/privacy)