# HippoDid

> Persistent, portable memory infrastructure for AI agents. Store and retrieve structured memories across Claude, ChatGPT, Cursor, and other AI tools via MCP and REST API.

## Docs

- [Quick Start](https://docs.hippodid.com/quickstart.html): Get started in 5 minutes — create a character, store a memory, and run a semantic search using curl, Java, or Python.
- [Authentication](https://docs.hippodid.com/authentication.html): API key (Bearer hd_key_*) and Clerk JWT authentication methods, rate limit headers, and Spring Security integration.
- [API Reference](https://docs.hippodid.com/api-reference.html): Complete REST API with 22 endpoints covering characters, memories, categories, file sync, and tier management. Interactive Redoc docs included.
- [MCP Setup](https://docs.hippodid.com/mcp-setup.html): Configure HippoDid as an MCP server in Claude Code, Claude Desktop, Cursor, Gemini CLI, Codex CLI, ChatGPT, and other clients. 21 tools available.
- [Spring Boot Starter](https://docs.hippodid.com/spring-boot-starter.html): Add persistent memory to Spring Boot AI agents in 3 lines of config. Maven/Gradle coordinates, semantic search, and multi-tenant support. Requires Java 21+.
- [BYOK AI](https://docs.hippodid.com/byok.html): Bring Your Own Key — use your own OpenAI, Anthropic, or self-hosted LLM keys. HippoDid handles infrastructure only; no AI markup.
- [Tiers and Limits](https://docs.hippodid.com/tiers.html): Four tiers (Free, Starter, Developer, Business) with rate limits, character caps, sync intervals, and feature comparison.

## Concepts

- [What is Persistent AI Memory?](https://docs.hippodid.com/concepts/persistent-memory.html): Explains the extraction-storage-retrieval-decay pipeline that gives AI agents long-term memory across sessions and platforms.
- [How MCP Connects AI Tools](https://docs.hippodid.com/concepts/mcp-explained.html): How Model Context Protocol standardizes AI-to-tool connections, enabling shared memory across Claude, ChatGPT, and Cursor.

## Guides

- [Add Memory to Claude Code](https://docs.hippodid.com/guides/claude-memory.html): Step-by-step setup for Claude Code integration via .mcp.json, with 19 tools for memory storage, search, and file sync.
- [Connect ChatGPT to External Memory](https://docs.hippodid.com/guides/chatgpt-memory.html): OAuth 2.1 with PKCE integration for ChatGPT Business/Enterprise/Edu. Enables cross-platform memory sharing with Claude and Cursor.

## Product

- [HippoDid Homepage](https://hippodid.com): Product overview, pricing (Free to $99/mo), comparison vs Mem0, and infrastructure details. Java-first, Apache 2.0 SDK.
- [OpenClaw Plugin](https://docs.hippodid.com/openclaw-plugin.html): Integration with OpenClaw workspace for automatic memory sync and compaction safety.

## Articles

- [Your AI Tools Don't Talk to Each Other](https://hippodid.com/articles/cross-tool-memory-bridge): Why fragmentation between conversational and task-focused AI costs developers hours daily, and how shared memory infrastructure solves it. By Yang Jing, March 2026.

## Key Facts

- Built by SameThoughts Inc., founded by Yang Jing
- Java 21 + Spring Boot 3.x backend deployed on GCP Cloud Run
- Open-source components (Spring Boot Starter, MCP Server) are Apache 2.0 licensed
- BYOK model: users provide their own AI keys (OpenAI, Anthropic, or self-hosted)
- Supports Claude Code, Claude Desktop, Cursor, Gemini CLI, Codex CLI, ChatGPT, and OpenClaw
- 22 REST API endpoints, 21 MCP tools
- Four pricing tiers: Free (3 characters), Starter, Developer (30 characters), Business (100 characters)
- Semantic search with relevance scoring and configurable memory decay

## Contact

- Website: https://hippodid.com
- Documentation: https://docs.hippodid.com
- Support: support@hippodid.com
- GitHub: https://github.com/SameThoughts/hippodid-spring-boot-starter
- Dashboard: https://app.hippodid.com