ProjectMakersDE/horizOn-mcp

**MCP server for horizOn Backend-as-a-Service**
Gives AI coding assistants documentation, live API tools, and workflow prompts for game and app development.
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Quick Install
Add to your MCP client configuration (Claude Desktop, Cursor, etc.):
Features
Resources (18 docs)
Documentation resources are served directly from the MCP server. No API key required.
| URI | Description |
|-----|-------------|
| horizon://overview | What is horizOn, core concepts (Account vs User), features, tier system, API structure, and SDKs |
| horizon://docs/auth | Authentication methods (Anonymous, Email, Google), endpoints, SDK code examples, and common errors |
| horizon://docs/leaderboard | Leaderboard score submission, top entries, user rank, entries around user, player profile per entry, validated only boards, with SDK examples |
| horizon://docs/cloud-save | Cloud save/load for JSON and binary data, tier size limits, SDK examples |
| horizon://docs/remote-config | Server-side key-value configuration: feature flags, game balance, A/B testing. SDK examples |
| horizon://docs/localization | Server-side localized strings across 15 languages: per-key translations, single/all fetch, available languages. SDK examples |
| horizon://docs/news | In-game news and announcements with language filtering. SDK examples |
| horizon://docs/gift-codes | Gift code validation and redemption for promotional rewards, including cosmetic unlocks via grants. SDK examples |
| horizon://docs/player-profile | Player avatar, frame and badges from a per-project cosmetics catalog, unlocks via gift code grants, profile in leaderboard entries. SDK examples |
| horizon://docs/validated-actions | Server-checked runs: single-use run tickets with a server seed, SHA-256 input log hash, server-only rules, validated only leaderboards, server-owned player state, start context, evidence upload, admin evidence review with sus packages and package export, rejection codes. SDK examples |
| horizon://docs/feedback | Bug reports, feature requests, and general feedback submission. SDK examples |
| horizon://docs/user-logs | Server-side event and error tracking. Requires BASIC tier or higher. SDK examples |
| horizon://docs/crash-reporting | Crash report submission, session tracking, fingerprinting, breadcrumbs, and auto-regression detection. SDK examples |
| horizon://docs/email-sending | Transactional and event-based email delivery to registered users. Templates, scheduling, status tracking, and SMTP integration. SDK examples |
| horizon://api/reference | Complete API reference for all horizOn App API endpoints with request/response schemas |
| horizon://quickstart/godot | Step-by-step guide to integrate horizOn in Godot with GDScript examples |
| horizon://quickstart/unity | Step-by-step guide to integrate horizOn in Unity with C# examples |
| horizon://quickstart/unreal | Step-by-step guide to integrate horizOn in Unreal Engine 5.5+ with the official horizOn SDK plugin. C++ and Blueprint examples |
Tools (34 tools)
Live API tools that call the horizOn backend. Requires a valid API key.
horizon_submit_score, horizon_save_cloud_data, horizon_load_cloud_data, horizon_redeem_gift_code, horizon_get_profile, horizon_set_profile, horizon_start_run, horizon_submit_validated, horizon_get_state and horizon_upload_evidence also need the player's session: sign in first and pass the returned accessToken as sessionToken.
Every tool declares MCP annotations (readOnlyHint, destructiveHint, idempotentHint, openWorldHint), so clients can tell reads from writes. Destructive tools are horizon_save_cloud_data (replaces the save), horizon_set_profile (replaces the whole profile), horizon_submit_validated (consumes the ticket, can spend balances) and horizon_cancel_email. The read tools that return an object also declare an outputSchema and return structuredContent next to the JSON text. Each description names when to use the tool, which sibling to use instead, what it returns and how to recover from its errors.