# Bitcall API

- [Overview](/docs): The Bitcall API gateway — one authenticated entry point to every Bitcall product.
- [Quick Start](/docs/quickstart): Get an API key and make your first authenticated request.
- [Authentication](/docs/authentication): Authenticate requests to the gateway with your key id and secret.
- The Gateway
  - [API Keys & Secrets](/docs/gateway/api-keys): What an API key is, how the secret works, and the key lifecycle.
  - [Get & Manage Keys](/docs/gateway/managing-api-keys): Create a key from your panel, capture the secret, and rotate or revoke it later.
  - [Conventions](/docs/gateway/conventions): The response envelopes, pagination, timestamps, money and request ids that every endpoint shares.
  - [Balance](/docs/gateway/balance): Read your account balance — the one every Bitcall product is charged against.
  - [Errors](/docs/gateway/errors): One error shape, thirteen codes, and what to do about each.
  - [Rate Limits](/docs/gateway/rate-limits): How request quotas are counted and what to do when you hit one.
- Products
  - [Products](/docs/products): The products available through the Bitcall API gateway.
  - OTP
    - [OTP Overview](/docs/products/otp): Rent numbers and receive one-time passcodes through the gateway.
  - [eSIM](/docs/products/esim): Provision and manage eSIM profiles through the gateway.
  - [HLR](/docs/products/hlr): Home Location Register lookups through the gateway.