---
title: "Reference"
description: "Package names, @paykernel/core runtime exports, error classes, stable payment events, and built-in gateway capability claims."
---

> Documentation Index
> Fetch the complete documentation index at: https://paykernel-docs.abshahin.workers.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Reference

This section is a **catalog**, not a tutorial. Names and cells come from `packages/*/package.json`, `packages/core/docs/baseline/public-api.inventory.json`, `packages/core/src/errors.ts`, `STABLE_PAYMENT_EVENT_TYPES`, and the generated capability matrix. If this site and those files disagree, **code wins**.

All packages are **published** (`core` 1.0.0, gateways/testkit 1.0.1, others 0.1.1/0.1.0) on the public registry.

:::caution[Honesty]
- Folder `packages/observability` publishes as **`@paykernel/opentelemetry`**. Never `@paykernel/observability`.
- `@paykernel/internal-sql-store` is **private**. Do not install it. It is a BC shim over `@paykernel/sql-foundation`.
- `handleWebhook` verifies and normalizes. It does **not** claim, lease, or set HTTP status.
- **Never fulfill in `onWebhookVerified`.** Fulfill after an inbox **claim**, and only when the rematched event is `payment.succeeded` or `capture.completed` **and** `payment.status === "paid"`, bound to `gatewayPaymentId`.
- `success: true` is not the fulfillment signal. Use `isPaidOutcome` / `outcome`.
- HTTP status codes live in `@paykernel/integration-http` (`mapInboxOutcome`), not in `@paykernel/webhooks`.
:::

## Pages

| Page | Source |
| --- | --- |
| [Packages](/reference/packages) | `packages/*/package.json` `name`, `version`, `exports` keys |
| [Core API](/reference/core-api) | `public-api.inventory.json` runtime + type-only exports |
| [Errors](/reference/errors) | Classes from `packages/core/src/errors.ts` re-exported by `index.ts` |
| [Events](/reference/events) | `packages/core/docs/webhook-events.md` + `STABLE_PAYMENT_EVENT_TYPES` |
| [Capabilities](/reference/capabilities) | Generated `packages/core/docs/gateway-capabilities.md` |

Guides for composition: [getting started](/guides/getting-started), [outcomes](/guides/outcomes), [webhooks](/guides/webhooks), [packages](/packages).

Source: https://paykernel-docs.abshahin.workers.dev/reference/index.mdx