# Wind

> Metered billing gateway for AI. A user funds a Wind balance once; your app adds a
> "Connect with Wind" button and then draws from that balance per inference call,
> priced as provider cost x a multiplier. Your app never holds a provider key or
> sees the user's card.

Auth is redirect-only OAuth 2.0 (authorization code + PKCE). The per-user
credential is a connection access/refresh token, not a static API key. Money is
integer micro-cents, USD (100_000_000 mc = $1.00; 1¢ = 1_000_000 mc). New apps run in a sandbox with a
fake balance and a mock or live-models provider.

## Start
- [Overview](https://docs.usewind.app/): What Wind is, and the one flow that defines it.
- [Quickstart](https://docs.usewind.app/quickstart): Add Connect with Wind to an application. Choose an integration path.

## Concepts
- [Concepts](https://docs.usewind.app/concepts): The objects Wind is built from, and how they relate.
- [Allocations & balance](https://docs.usewind.app/allocations-and-balance): Reservation lifecycle, holds, non-refilling semantics, increases, revocation.
- [Sandbox & going live](https://docs.usewind.app/sandbox-and-going-live): Test accounts and their fake balances, mock vs live models, and the tier ladder.

## Integrate
- [Agents & LLMs](https://docs.usewind.app/agents-and-llms): Machine-readable docs and a drop-in skill for coding agents.
- [Connect button & SDK](https://docs.usewind.app/connect-button-and-sdk): The hosted connect button web component and the @usewind/browser and @usewind/node packages.
- [REST API integration](https://docs.usewind.app/rest-api): The complete connect flow without an SDK, in six steps.

## Protocol
- [Authentication](https://docs.usewind.app/authentication): The auth-code + PKCE flow, access & refresh tokens, and client credentials.
- [Making requests](https://docs.usewind.app/making-requests): The inference endpoint — body, response, streaming, feature tagging, idempotency.
- [Voice sessions](https://docs.usewind.app/voice-sessions): Live speech-to-speech with OpenAI Realtime models, billed per reply from the user's balance.
- [Webhooks](https://docs.usewind.app/webhooks): Signed lifecycle events Wind POSTs to your endpoint.

## Reference
- [API Reference](https://docs.usewind.app/api-reference): Every endpoint, rendered from the OpenAPI spec.
- [Errors & types](https://docs.usewind.app/errors-and-types): The error envelope, every code, and the shapes you get back.
- [SDKs](https://docs.usewind.app/sdks): Official Wind SDKs and their status.

## Machine-readable

- [Full docs, one file](https://docs.usewind.app/llms-full.txt): every page above, concatenated
- [OpenAPI spec](https://docs.usewind.app/openapi.yaml): the API contract, source of truth
- [wind-connect skill](https://docs.usewind.app/skills/wind-connect/SKILL.md): step-by-step instructions for an agent wiring up the connect flow