# halfin docs > Public developer documentation for API keys, hosted invoice checkout, static addresses, payouts, webhooks, balances, public data, and environments. Use Get Started and Payment Flows for the current merchant integration path, then use the API Reference section for generated per-operation documentation. ## Pages - [Changelog](https://docs.halfin.xyz/changelog): Public API changes Markdown: https://docs.halfin.xyz/md/changelog - [Environments](https://docs.halfin.xyz/environments): Test and production separation Markdown: https://docs.halfin.xyz/md/environments - [Get Started](https://docs.halfin.xyz/get-started): Create a first invoice with the merchant API. Markdown: https://docs.halfin.xyz/md/get-started - [Overview](https://docs.halfin.xyz/): Public developer documentation for addresses, invoices, payouts, webhooks, and the merchant API. Markdown: https://docs.halfin.xyz/md - [Addresses](https://docs.halfin.xyz/concepts/addresses): Ephemeral invoice addresses and reusable static addresses Markdown: https://docs.halfin.xyz/md/concepts/addresses - [Authentication](https://docs.halfin.xyz/concepts/authentication): Use API keys for merchant integrations Markdown: https://docs.halfin.xyz/md/concepts/authentication - [Balances and Ledger](https://docs.halfin.xyz/concepts/balances-ledger): Available funds and audit trail Markdown: https://docs.halfin.xyz/md/concepts/balances-ledger - [Errors](https://docs.halfin.xyz/concepts/errors): Error envelope, retry behavior, and support IDs Markdown: https://docs.halfin.xyz/md/concepts/errors - [Idempotency](https://docs.halfin.xyz/concepts/idempotency): Retry safely without duplicate resources Markdown: https://docs.halfin.xyz/md/concepts/idempotency - [Invoices](https://docs.halfin.xyz/concepts/invoices): One-time payment requests Markdown: https://docs.halfin.xyz/md/concepts/invoices - [Pagination](https://docs.halfin.xyz/concepts/pagination): List endpoints use limit and offset Markdown: https://docs.halfin.xyz/md/concepts/pagination - [Payouts](https://docs.halfin.xyz/concepts/payouts): Send funds from merchant balance Markdown: https://docs.halfin.xyz/md/concepts/payouts - [Authentication](https://docs.halfin.xyz/guides/authentication): API key types, header format, and security best practices Markdown: https://docs.halfin.xyz/md/guides/authentication - [Error Handling](https://docs.halfin.xyz/guides/error-handling): Error envelope format, error codes, and idempotency keys Markdown: https://docs.halfin.xyz/md/guides/error-handling - [Guides](https://docs.halfin.xyz/guides): Practical integration guides for the public merchant API. Markdown: https://docs.halfin.xyz/md/guides - [Payment Flows](https://docs.halfin.xyz/guides/payment-flows): Follow the current invoice payment-link flow for merchant integrations. Markdown: https://docs.halfin.xyz/md/guides/payment-flows - [Rate Limits](https://docs.halfin.xyz/guides/rate-limits): API rate limits and how to handle 429 responses Markdown: https://docs.halfin.xyz/md/guides/rate-limits - [Static Addresses](https://docs.halfin.xyz/guides/static-addresses): Create permanent deposit addresses for top-ups and recurring deposits Markdown: https://docs.halfin.xyz/md/guides/static-addresses - [Webhooks](https://docs.halfin.xyz/webhooks): Receive real-time notifications for payment and payout events. Markdown: https://docs.halfin.xyz/md/webhooks - [Signature Verification](https://docs.halfin.xyz/webhooks/signature-verification): Verify webhook signatures before processing events. Markdown: https://docs.halfin.xyz/md/webhooks/signature-verification - [Cancel a pending invoice.](https://docs.halfin.xyz/api/merchant/cancelInvoice): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/cancelInvoice - [Cancel a payout.](https://docs.halfin.xyz/api/merchant/cancelPayout): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/cancelPayout - [Create a permanent static deposit address.](https://docs.halfin.xyz/api/merchant/createAddress): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/createAddress - [Create a new payment invoice.](https://docs.halfin.xyz/api/merchant/createInvoice): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/createInvoice - [Create a new payout.](https://docs.halfin.xyz/api/merchant/createPayout): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/createPayout - [Create a refund for a paid invoice.](https://docs.halfin.xyz/api/merchant/createRefund): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/createRefund - [Get a single static deposit address.](https://docs.halfin.xyz/api/merchant/getAddress): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/getAddress - [Get a single invoice with payment details.](https://docs.halfin.xyz/api/merchant/getInvoice): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/getInvoice - [Get ledger history for a specific currency.](https://docs.halfin.xyz/api/merchant/getLedger): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/getLedger - [Get a single payout.](https://docs.halfin.xyz/api/merchant/getPayout): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/getPayout - [Merchant API](https://docs.halfin.xyz/api/merchant): Invoices, payouts, refunds, addresses, and balances for API-key integrations. Markdown: https://docs.halfin.xyz/md/api/merchant - [List invoices for a static address.](https://docs.halfin.xyz/api/merchant/listAddressInvoices): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/listAddressInvoices - [List static deposit addresses.](https://docs.halfin.xyz/api/merchant/listAddresses): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/listAddresses - [List all currency balances for the authenticated merchant.](https://docs.halfin.xyz/api/merchant/listBalances): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/listBalances - [List invoices for the authenticated merchant.](https://docs.halfin.xyz/api/merchant/listInvoices): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/listInvoices - [List payouts for the authenticated merchant.](https://docs.halfin.xyz/api/merchant/listPayouts): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/merchant/listPayouts - [Get supported payment currencies.](https://docs.halfin.xyz/api/public/getCurrencies): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/public/getCurrencies - [Get current exchange rates.](https://docs.halfin.xyz/api/public/getRates): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/public/getRates - [Public API](https://docs.halfin.xyz/api/public): Exchange rates and supported currency metadata. Markdown: https://docs.halfin.xyz/md/api/public - [Webhooks](https://docs.halfin.xyz/api/webhooks): Webhook event payload schemas delivered to merchant endpoints. Markdown: https://docs.halfin.xyz/md/api/webhooks - [Merchant balance credited.](https://docs.halfin.xyz/api/webhooks/webhookBalanceCredited): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookBalanceCredited - [Invoice payment detected, awaiting confirmations.](https://docs.halfin.xyz/api/webhooks/webhookInvoiceConfirming): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookInvoiceConfirming - [A previously confirmed deposit was reversed (e.g. chain reorg).](https://docs.halfin.xyz/api/webhooks/webhookInvoiceDepositReversed): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookInvoiceDepositReversed - [Invoice expired without sufficient payment.](https://docs.halfin.xyz/api/webhooks/webhookInvoiceExpired): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookInvoiceExpired - [Late deposit received on an expired invoice.](https://docs.halfin.xyz/api/webhooks/webhookInvoiceLateDeposit): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookInvoiceLateDeposit - [Invoice received more than the requested amount.](https://docs.halfin.xyz/api/webhooks/webhookInvoiceOverpaid): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookInvoiceOverpaid - [Invoice fully paid.](https://docs.halfin.xyz/api/webhooks/webhookInvoicePaid): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookInvoicePaid - [Invoice expired with partial payment.](https://docs.halfin.xyz/api/webhooks/webhookInvoiceUnderpaid): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookInvoiceUnderpaid - [Payout successfully broadcast and confirmed.](https://docs.halfin.xyz/api/webhooks/webhookPayoutCompleted): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookPayoutCompleted - [Payout failed, funds released.](https://docs.halfin.xyz/api/webhooks/webhookPayoutFailed): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookPayoutFailed - [Refund completed on-chain.](https://docs.halfin.xyz/api/webhooks/webhookRefundCompleted): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookRefundCompleted - [Refund created and funds reserved.](https://docs.halfin.xyz/api/webhooks/webhookRefundCreated): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookRefundCreated - [Refund failed, reserved funds released.](https://docs.halfin.xyz/api/webhooks/webhookRefundFailed): halfin public developer documentation. Markdown: https://docs.halfin.xyz/md/api/webhooks/webhookRefundFailed - [TypeScript SDK](https://docs.halfin.xyz/guides/sdks/typescript): Install and use the official halfin TypeScript SDK Markdown: https://docs.halfin.xyz/md/guides/sdks/typescript ## Machine-Readable Resources - [OpenAPI](https://docs.halfin.xyz/openapi/openapi.yaml): Filtered public OpenAPI document for merchant integrations. - [Sitemap](https://docs.halfin.xyz/sitemap.xml): Public documentation and API reference sitemap. - [Full LLM text](https://docs.halfin.xyz/llms-full.txt): Curated Markdown bundle for the pages listed above.