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

# Glossary

> Definitions for key terms used across Xquik documentation

<blockquote className="agent-llms-directive">
  For the complete documentation index, see <a href="/llms.txt">llms.txt</a>.
</blockquote>

Quick reference for terminology used throughout the Xquik platform and API.

## Core concepts

<AccordionGroup>
  <Accordion title="Monitor">
    A persistent watcher on an X user or keyword query that streams events via webhooks. Monitor slots are unlimited. Active instant monitors check every 1 second and cost 21 credits per hour.
  </Accordion>

  <Accordion title="Extraction">
    A batch job that pulls historical data (tweets, followers, etc.) into exportable results. Extractions are metered operations - credit cost depends on the volume of data returned.
  </Accordion>

  <Accordion title="Draw">
    A giveaway selection tool that picks winners from extraction results. Draws support filters (minimum followers, account age) and produce a transparent, publicly verifiable result page.
  </Accordion>

  <Accordion title="Event">
    A change detected by a monitor (new tweet, follower gained, profile update, etc.). Events are delivered to your server via webhooks in real time.
  </Accordion>
</AccordionGroup>

## Billing & usage

<AccordionGroup>
  <Accordion title="Credits">
    The metered unit for API usage. Credit cost depends on the endpoint, returned result count, draw filters, media upload, or active monitor hours. Subscription grants, top-ups, and automatic top-ups add credits to one shared balance. Unused credits carry over until you spend them.
  </Accordion>

  <Accordion title="Metered">
    Operations that deduct credits from your balance. Includes reads, writes, and extractions. When credits are exhausted, metered calls return `402 Payment Required`.
  </Accordion>

  <Accordion title="Non-metered">
    Operations that are free and do not consume credits. Includes reading and managing stored monitor records, stored event reads, webhooks, and account management endpoints. Active instant monitors are billed hourly while enabled.
  </Accordion>

  <Accordion title="PAYG">
    Pay-as-you-go - purchase credits on demand via top-up at USD 0.00015/credit. Top-up credits are added to your balance immediately and do not expire.
  </Accordion>

  <Accordion title="MPP">
    Machine Payments Protocol - pay-per-call with USDC, no subscription required. Designed for autonomous agents that pay for each API call individually.
  </Accordion>
</AccordionGroup>

## Delivery

<AccordionGroup>
  <Accordion title="Webhook">
    An HTTP callback that delivers real-time monitor events to your server. Webhooks use HMAC-SHA256 signatures for payload verification. See the [webhook guide](/webhooks/overview) for setup details.
  </Accordion>

  <Accordion title="Write action">
    An operation that modifies X state - tweet, like, follow, DM, etc. Most write actions cost 10 credits; tweet and reply posting costs are documented on [Create tweet](/api-reference/x-write/create-tweet). Write actions require a connected X account.
  </Accordion>
</AccordionGroup>

## API & technical

<AccordionGroup>
  <Accordion title="API key">
    Authentication credential passed via the `x-api-key` header. Generate keys from the [API Keys dashboard](https://dashboard.xquik.com/en/account?tab=api-keys) or the [API keys endpoint](/api-reference/api-keys/create).
  </Accordion>

  <Accordion title="Cursor-based pagination">
    A pagination method using opaque cursor tokens instead of page numbers. Pass the `cursor` value from the previous response to fetch the next page. More reliable than offset-based pagination for real-time data.
  </Accordion>

  <Accordion title="Fixed window counter">
    The rate-limiting algorithm used by Xquik. Each user account gets a counter per tier. Read counters reset every 1 second; write and delete counters reset every 60 seconds. Requests are rejected with 429 when the counter exceeds the tier limit. See [rate limits](/guides/rate-limits) for details.
  </Accordion>
</AccordionGroup>