> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kanarie.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# x402 fallback

> How Kanarie exposes paid per-request fallback for public data endpoints.

Most public content, project, data, and wallet endpoints support API-key authentication first, then x402 payment fallback.

The fallback applies when:

* No API key header is present.
* An API key is malformed, invalid, revoked, expired, or otherwise fails client-side authentication.
* A valid API key exceeds its free or paid plan limit for an x402-enabled endpoint.

The fallback does not apply when:

* Backend validation fails because of an internal server or database error.

## Paid endpoints

x402 fallback is available on these endpoint families:

* `/api/v1/content/*`
* `/api/v1/projects/search`
* `/api/v1/projects/filter`
* `/api/v1/projects/mindshare-map`
* `/api/v1/projects/technical-analysis`
* `/api/v1/data/*`
* `/api/v1/data/wallets/*`

The API reference includes `402` responses on x402-enabled endpoints. The Mintlify playground is configured for API-key usage as the primary path.

## Pricing model

Pricing is calculated per request from route-specific inputs such as `limit`, query count, selected attributes, and timeframes. The API advertises payment requirements through the x402 response flow when a paid request is required.