# Expereon API

> Expereon is a B2B financial platform API for the travel services marketplace: connections, bookings, invoices, payments, treasury (balances, transactions, withdrawals, refunds), plus API keys, webhooks and logs. This file indexes the integration docs and per-domain endpoint references for external integrators and their coding agents.

Base URLs: `https://api.expereon.com`, `https://sandbox.expereon.com`. Auth: send `X-API-Key` and `X-API-Secret` on every request. Interactive reference (OpenAPI): [https://openapi.expereon.org/index.html](https://openapi.expereon.org/index.html). Machine-readable spec: [https://openapi.expereon.org/openapi.json](https://openapi.expereon.org/openapi.json).

## Guides

- [Getting Started](https://openapi.expereon.org/llms/getting-started.md): Zero to your first authenticated API call in five minutes.
- [Authentication](https://openapi.expereon.org/llms/authentication.md): API key + secret headers, environments, key prefixes, rotation.
- [Architecture](https://openapi.expereon.org/llms/architecture.md): The API domains and how connections, bookings, invoices and payments relate.
- [Pagination And Idempotency](https://openapi.expereon.org/llms/pagination-and-idempotency.md): 0-based pagination, page-size limits, and safe retries via requestId.
- [Webhooks](https://openapi.expereon.org/llms/webhooks.md): Subscribe to events, verify HMAC signatures, retry policy, event catalog.
- [Errors](https://openapi.expereon.org/llms/errors.md): Error envelope, HTTP status codes, common error codes, retry strategy.

## API reference (by domain)

- [Bookings](https://openapi.expereon.org/llms/api/bookings.md): Submit bookings and let Expereon auto-generate the matching invoice. Covers buyer and seller submissions, batch submission, updates, completion, cancellation, and two-sided reconciliation.
- [External Sellers](https://openapi.expereon.org/llms/api/external-sellers.md): Create and manage external (off-platform) seller profiles and link them to platform sellers.
- [Invoices](https://openapi.expereon.org/llms/api/invoices.md): Create, retrieve, update, and manage invoices. Invoices represent billing documents between connected buyer and seller organizations.
- [Invoice Actions](https://openapi.expereon.org/llms/api/invoice-actions.md): Workflow actions on invoices - approve, dispute, cancel, settle, and manage cancellation requests.
- [Invoice Bulk Operations](https://openapi.expereon.org/llms/api/invoice-bulk-operations.md): Perform actions on multiple invoices at once - bulk approve, cancel, archive, and restore.
- [Invoice Line Items](https://openapi.expereon.org/llms/api/invoice-line-items.md): Manage individual line items, attachments, and file downloads on invoices.
- [Invoice Notes](https://openapi.expereon.org/llms/api/invoice-notes.md): Add and retrieve notes on invoices for communication between parties.
- [Invoice History](https://openapi.expereon.org/llms/api/invoice-history.md): View the full audit trail of changes and status transitions for an invoice.
- [Payments](https://openapi.expereon.org/llms/api/payments.md): Settle invoices, view payment history, and export payment records. Supports single, bulk, and settle-all-due workflows.
- [Connections](https://openapi.expereon.org/llms/api/connections.md): View and manage business relationships between buyer and seller organizations.
- [Balances](https://openapi.expereon.org/llms/api/balances.md): View organization balances across different balance types (available, collateral, etc.).
- [Transactions](https://openapi.expereon.org/llms/api/transactions.md): View transaction history - deposits, withdrawals, settlements, and other financial movements.
- [Withdrawals](https://openapi.expereon.org/llms/api/withdrawals.md): Submit, approve, reject, and cancel withdrawal requests from organization balances.
- [Refunds](https://openapi.expereon.org/llms/api/refunds.md): Create, approve, and reject refund requests for completed transactions.
- [API Keys](https://openapi.expereon.org/llms/api/api-keys.md): Create and manage API keys for programmatic access. Keys support production and sandbox environments.
- [Webhooks](https://openapi.expereon.org/llms/api/webhooks.md): Configure webhook endpoints to receive real-time notifications about events in your account.
- [API Logs](https://openapi.expereon.org/llms/api/api-logs.md): View logs of API requests made using your API keys - useful for debugging and auditing.
- [Storage](https://openapi.expereon.org/llms/api/storage.md): Upload and download files (invoice attachments, documents).
- [Additional Endpoints](https://openapi.expereon.org/llms/api/additional-endpoints.md): 11 endpoints.
- [Invoice Attachments](https://openapi.expereon.org/llms/api/invoice-attachments.md): 4 endpoints.

## Optional

- [Full docs in one file](https://openapi.expereon.org/llms-full.txt): every guide and endpoint reference concatenated, for one-shot context loading.