# Splitwise

> Splitwise is a fair-splitting expense-sharing service. Its Self-Serve REST API (v3.0) lets applications read and manage a user's groups, friends, expenses, comments, and notifications on the user's behalf.

Generated by the API Evangelist enrichment pipeline on 2026-07-21 from the public
Splitwise API documentation and OpenAPI spec. No /llms.txt is published by Splitwise.

- Base URL: https://secure.splitwise.com/api/v3.0
- Documentation: https://dev.splitwise.com/
- Register an app / get keys: https://secure.splitwise.com/apps
- Auth: OAuth 2.0 (authorization code) or a personal API key, both sent as `Authorization: Bearer <token>`
- Status: https://status.splitwise.com/

## API

- [OpenAPI 3.0 specification](openapi/splitwise-openapi.json): Splitwise API v3.0 — 27 operations across users, groups, friends, expenses, comments, notifications, and reference data.
- [Authentication profile](authentication/splitwise-authentication.yml): OAuth 2.0 authorization-code flow plus personal API key (Bearer).
- [Conventions](conventions/splitwise-conventions.yml): success/error envelope, limit/offset pagination, path-based versioning, rate-limit posture.
- [Error catalog](errors/splitwise-problem-types.yml): 400/401/403/404 envelope shapes and remediation.
- [Data model](data-model/splitwise-data-model.yml): User, Group, Friend, Expense, Share, Debt, Comment, Notification, Category entity graph.
- [Lifecycle](lifecycle/splitwise-lifecycle.yml): v3.0 path-based versioning; no documented deprecation policy.

## Notes

- A 200 OK does not guarantee success — always inspect the response body `success` and `errors` fields.
- No idempotency-key mechanism; retries of write operations can create duplicates.
- Activity is retrieved by polling `/get_notifications`; there is no webhook surface.
- Community-built client libraries exist for many languages (see packages/splitwise-packages.yml); Splitwise ships no first-party SDK.