> ## Documentation Index
> Fetch the complete documentation index at: https://docs.attio.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Authorize
Query Parameters
Your app's client ID. You can find this in your app's settings pages at
[build.attio.com](https://build.attio.com).
The response type. This should always be `"code"`.
The URL to redirect to after the user authorizes access to your app. This URL must exactly match
one of the registered redirect URLs in your app's settings pages at
[build.attio.com](https://build.attio.com).
A random string to prevent CSRF attacks. Set this when starting the OAuth flow and verify it
matches when the user is redirected back to your app.
The [level](/rest-api/guides/authentication#token-levels) of the access token, either
`"workspace"` or `"user"`. A `"user"` token requires `code_challenge` and `code_challenge_method`.
A [PKCE](https://datatracker.ietf.org/doc/html/rfc7636) code challenge: the base64url-encoded
SHA-256 hash of a code verifier. Required when `token_level` is `"user"`. Pass the code verifier
as `code_verifier` when you exchange the code at the [token endpoint](/docs/oauth/token).
The PKCE code challenge method. This should always be `"S256"`. Required when `code_challenge` is
set.
Response
After the user approves the connection, they are redirected to the `redirect_uri` with a `code`
query parameter. If provided, the original `state` is also included.
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