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

# What is qlaud?

> The billing layer for AI apps. Mint a key per user, cap their spend, get paid.

## The pitch

You shipped an AI app. You have N end-users hitting Claude / GPT / Sora through
your backend. Now you need:

* per-user usage tracking
* per-user spending caps
* monthly invoicing
* failed-payment handling
* one bill from one provider, not five

**qlaud is the billing layer.** Mint a `qlk_live_…` key per user when they sign
up to your app. We meter every request to that key, enforce a hard cap, and
report per-user spend you can pipe straight into Stripe.

## What you get

<CardGroup cols={2}>
  <Card title="Per-user keys" icon="key">
    `POST /v1/keys` returns a `qlk_live_…` you store with that user. Optional
    `max_spend_usd` is enforced gateway-side on every request.
  </Card>

  <Card title="Per-user usage" icon="chart-line">
    `GET /v1/usage` returns spend, requests, and tokens broken down by every
    key you've minted. Pipe it into Stripe at month-end.
  </Card>

  <Card title="Frontier models" icon="sparkles">
    Claude Opus 4.7, GPT-5.4, Sora 2, Eleven, Whisper, Deepgram, Perplexity —
    all behind one key. No per-provider integration.
  </Card>

  <Card title="Anthropic + OpenAI shape" icon="plug">
    Native `/v1/messages` AND `/v1/chat/completions` — drop-in for Claude Code,
    Cursor, Cline, openai-py, LangChain, Vercel AI SDK.
  </Card>
</CardGroup>

## Who it's for

If you're building **a product that wraps an AI model and sells it to end-users**,
qlaud removes the entire billing-infrastructure layer.

* Building an AI writing tool? Mint a key per writer.
* Coding agent for teams? Mint a key per developer seat.
* Voice agent SaaS? Mint a key per phone number.
* Image-gen for designers? Mint a key per designer.

You write your app. We do the metering, capping, and per-user reporting.

## The 30-second demo

```bash theme={null}
# 1. Mint your master key in the dashboard, then:
export QLAUD_MASTER_KEY=qlk_live_...

# 2. Mint a key for user_42 with a $5 monthly cap
curl https://api.qlaud.ai/v1/keys \
  -H "x-api-key: $QLAUD_MASTER_KEY" \
  -H "content-type: application/json" \
  -d '{"name":"user_42","max_spend_usd":5}'
# → {"id":"...","secret":"qlk_live_abc...","scope":"standard","max_spend_usd":5}

# 3. user_42 makes requests with their qlk_live_abc... key. We enforce the cap.

# 4. End of month — pull spend per user
curl https://api.qlaud.ai/v1/usage -H "x-api-key: $QLAUD_MASTER_KEY"
# → {"by_key":[{"key_name":"user_42","cost_micros":2347000,...}], ...}
```

That's it. Read the [per-user billing quickstart](/per-user-billing) for the full
flow with Node + Python + Stripe wiring.

## Beyond billing — the app substrate

Once your end-users are minted as keys, qlaud manages the rest of the AI
app stack so you don't have to:

<CardGroup cols={2}>
  <Card title="Threads" icon="comments" href="/api-reference/threads">
    Conversation memory primitive. Send just the new turn — qlaud loads
    history server-side, persists both sides, returns the assistant
    response. Kills the `messages` table.
  </Card>

  <Card title="Tools" icon="bolt" href="/api-reference/tools">
    Register a webhook URL once. When the assistant emits `tool_use`,
    qlaud calls your endpoint, awaits the result, re-calls the model.
    Cross-provider — same shape for Claude or GPT.
  </Card>

  <Card title="Search" icon="magnifying-glass" href="/api-reference/search">
    Every turn auto-embedded into Cloudflare Vectorize. Query with plain
    text, get tenant-isolated semantic hits. No vector DB to provision.
  </Card>

  <Card title="Jobs" icon="clock" href="/api-reference/jobs">
    Async submit + polled retrieval for long-running batch work. Same
    request body as the synchronous endpoints, wrapped in `/v1/jobs`.
  </Card>
</CardGroup>

For the full picture — building a complete chat product (per-user threads,
tools, search, streaming UX, billing) end-to-end — see the
[**Build a chat app**](/guides/build-a-chat-app) tutorial.