# TxNod documentation

> TxNod is a non-custodial crypto payment gateway. The TypeScript SDK is pure Node ≥ 20 and runs in any server-side framework (Express, Fastify, Hono, Koa, NestJS, plain `node:http`, Next.js App Router or Pages, Nuxt, SvelteKit, Remix, Astro endpoints, …). It supports BTC; ETH + ERC-20 (USDT/USDC); POL + Polygon USDT/USDC; BNB + BEP-20 USDT/USDC; TRX + TRC-20 USDT; ADA; and TON + jetton USDT — fifteen assets across seven chains. This index lists every documentation page so an AI coding agent can walk the full corpus from a single URL. Each entry links to the rendered page AND to the raw-Markdown form ([.md]) so agents can fetch either representation. If you have installed `@txnod/sdk`, a full, version-matched copy of the SDK documentation is bundled inside the npm tarball at `node_modules/@txnod/sdk/docs/` with an agent-entry doc at `node_modules/@txnod/sdk/AGENTS.md` — prefer those offline files over fetching this site when you are integrating the SDK, since they are frozen at your installed SDK version and require no network access.

## Getting Started

- [Overview](https://docs.txnod.com/): TxNod — a non-custodial crypto payment gateway. [.md](https://docs.txnod.com/index.md)
- [Quickstart](https://docs.txnod.com/quickstart): Get from zero to a verified testnet invoice. [.md](https://docs.txnod.com/quickstart.md)

## API Reference

- [Invoices](https://docs.txnod.com/api/invoices): Create, retrieve, search, and cancel invoices. [.md](https://docs.txnod.com/api/invoices.md)
- [Orphan Payments](https://docs.txnod.com/api/orphan-payments): List and attribute unmatched transactions. [.md](https://docs.txnod.com/api/orphan-payments.md)
- [Inbound Webhooks](https://docs.txnod.com/api/webhooks): Partner-configured webhook subscription management. [.md](https://docs.txnod.com/api/webhooks.md)
- [Sandbox simulation API](https://docs.txnod.com/api/sandbox): POST /api/v1/sandbox/* endpoint reference with cross-mode error codes. [.md](https://docs.txnod.com/api/sandbox.md)

## SDK

- [TxnodClient](https://docs.txnod.com/sdk/client): Primary REST client with automatic HMAC signing. [.md](https://docs.txnod.com/sdk/client.md)
- [verifyWebhookSignature](https://docs.txnod.com/sdk/verify-webhook-signature): Webhook HMAC + timestamp verification helper. [.md](https://docs.txnod.com/sdk/verify-webhook-signature.md)
- [Errors](https://docs.txnod.com/sdk/errors): Typed error class hierarchy matching every API error code. [.md](https://docs.txnod.com/sdk/errors.md)
- [client.sandbox.* surface](https://docs.txnod.com/sdk/sandbox): SDK helper reference for the sandbox simulation surface plus environment-detection guards. [.md](https://docs.txnod.com/sdk/sandbox.md)

## Webhooks

- [Webhook Event Types](https://docs.txnod.com/webhooks/events): Canonical list of webhook event types and envelopes. [.md](https://docs.txnod.com/webhooks/events.md)

## Guides

- [How to export your xpub](https://docs.txnod.com/guides/xpub-export): Extract an extended public key from Ledger Live, Sparrow, Electrum, or a Cardano CIP-30 browser wallet. [.md](https://docs.txnod.com/guides/xpub-export.md)
- [Wallets](https://docs.txnod.com/guides/wallets): How TxNod uses your xpub: privacy, index 0, the pool model, archival, and rotation. [.md](https://docs.txnod.com/guides/wallets.md)
- [Balance Sync](https://docs.txnod.com/guides/balance-sync): Staleness signals and the Ledger Live gap-limit caveat per chain family. [.md](https://docs.txnod.com/guides/balance-sync.md)
- [Billing](https://docs.txnod.com/guides/billing): How subscription expiry and payment-proportional top-ups work. [.md](https://docs.txnod.com/guides/billing.md)
- [API keys](https://docs.txnod.com/guides/api-keys): Generate, rotate, and revoke the project API key pair used to sign REST and webhook requests. [.md](https://docs.txnod.com/guides/api-keys.md)
- [Personal Access Tokens](https://docs.txnod.com/guides/personal-access-tokens): PAT scopes and the mandatory-expiry policy. [.md](https://docs.txnod.com/guides/personal-access-tokens.md)
- [Invoices](https://docs.txnod.com/guides/invoices): Reorg safety and per-chain confirmation thresholds at a glance. [.md](https://docs.txnod.com/guides/invoices.md)
- [Admin actions on your account](https://docs.txnod.com/guides/admin): What gets audit-logged when an admin grants or grandfathers your account. [.md](https://docs.txnod.com/guides/admin.md)
- [Configuring partner webhooks](https://docs.txnod.com/guides/webhooks): URL requirements and the HMAC signing protocol for partner webhook endpoints. [.md](https://docs.txnod.com/guides/webhooks.md)
- [Supported chains](https://docs.txnod.com/guides/supported-chains): The 13-asset / 6-chain matrix with default confirmation thresholds. [.md](https://docs.txnod.com/guides/supported-chains.md)
- [Sandbox projects](https://docs.txnod.com/guides/sandbox-projects): Create a sandbox project, walk through the agent loop, graduate to production. [.md](https://docs.txnod.com/guides/sandbox-projects.md)
- [Agent-driven testing](https://docs.txnod.com/guides/agent-driven-testing): How an AI coding agent uses sandbox simulate-* to walk all 7 webhook events deterministically. [.md](https://docs.txnod.com/guides/agent-driven-testing.md)
- [Sandbox safety](https://docs.txnod.com/guides/sandbox-safety): Per-chain format-safety truth table, seven-layer defense, and the recommended CI assertion. [.md](https://docs.txnod.com/guides/sandbox-safety.md)
- [MCP OAuth 2.1](https://docs.txnod.com/guides/mcp-oauth): How TxNod's MCP server speaks OAuth 2.1 to compliant MCP clients — discovery, registration, PKCE, audience binding, token TTLs, and per-client revocation. [.md](https://docs.txnod.com/guides/mcp-oauth.md)
- [Connect Claude Code](https://docs.txnod.com/guides/mcp-claude-code): Add the TxNod MCP server to Claude Code via the HTTP transport. [.md](https://docs.txnod.com/guides/mcp-claude-code.md)
- [Connect Cursor](https://docs.txnod.com/guides/mcp-cursor): Add the TxNod MCP server to Cursor via the HTTP transport. [.md](https://docs.txnod.com/guides/mcp-cursor.md)
- [Connect Claude Desktop](https://docs.txnod.com/guides/mcp-claude-desktop): Add the TxNod MCP server to Claude Desktop via the @txnod/mcp-stdio wrapper. [.md](https://docs.txnod.com/guides/mcp-claude-desktop.md)
- [Project kinds](https://docs.txnod.com/guides/project-kinds): How TxNod's three-way kind discriminator (production / testnet / sandbox) replaces the legacy per-invoice network flag. [.md](https://docs.txnod.com/guides/project-kinds.md)