The proxy is the drop‑in, OpenAI‑compatible layer that enforces pricing and authorization, meters usage, and returns paywall‑aware assistant messages. It dramatically simplifies setup because you don’t need to build billing branches in your app.
Optional but recommended: You can call Paywalls APIs directly for non‑chat features (e.g., manual charges). For chat usage, the proxy gives you the fastest path to a working, billable flow without custom billing code.

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Why use the proxy?

  • Zero‑branching UX — When a user must authorize or top up, the proxy replies with a normal assistant message containing the correct link. You just render what you get.
  • One client surface — Keep using OpenAI SDKs and tools; change only the base URL and key.
  • Consistent metering — Requests are normalized, streamed tokens are measured, and pricing is applied centrally.
  • Provider flexibility — Swap models/providers without rewriting your app or pricing logic.
  • Central guardrails — Spend caps, token caps, and rate limits enforce your rules before provider calls.

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What the proxy does

  • Compatibility — Accepts OpenAI‑style Chat Completions (incl. streaming, function/tool calls, JSON modes). (Modalities beyond text are roadmap‑dependent.)
  • Decisioning — Checks authorization (Shared), balance, and limits; decides whether to return a link or execute the request.
  • Routing — Forwards eligible requests to the selected provider (BYOK or built‑in) and proxies the stream back to you.
  • Metering & pricing — Counts tokens, computes charges, and writes ledger entries.
  • Observability — Attaches a request id and correlates ledger entries and events for support/analytics.

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Request lifecycle

1

Request

Your app calls the OpenAI‑compatible endpoint with a paywall key and a user id.
2

Decision

The proxy evaluates authorization (Shared), balance, limits, and pricing rules.
3

If action is needed

The response is a normal assistant message containing an authorization or checkout link. You render it as‑is; no special branching.
4

Execution

If authorized & funded, the request is forwarded to the configured provider (BYOK or built‑in). Streaming is passed through.
5

Meter & bill

— Token usage is measured; the applicable pricing rule computes the charge. A charge entry is written to the ledger.

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Security expectations

  • Your paywall API key must remain server‑side.
  • Always include a stable user id to prevent cross‑account leakage and enable correct limits.
  • Use idempotency keys for your own side‑effecting calls (e.g., manual charges) to avoid duplicates.

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Performance & limits

  • Streaming is proxied with minimal overhead; if a stream drops, clients may reconnect and retry safely.
  • Rate limits and concurrency caps protect your app and budget. (soon)

Model providers

BYOK vs Built-in Provider