HippoDid MCP Server
Persistent, portable memory for AI agents. Your AI forgets everything between sessions. HippoDid remembers.

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HippoDid MCP Server

MCP (Model Context Protocol) server for HippoDid — connects Claude Code, Claude Desktop, ChatGPT, Gemini CLI, Codex CLI, Cursor, and any MCP-compatible client to persistent AI character memory.

What is HippoDid?

HippoDid is a cloud memory infrastructure for AI agents. It stores structured memories (preferences, decisions, skills, relationships) in a searchable database and retrieves them across sessions, tools, and AI providers. Write a memory in Claude Code, recall it in ChatGPT. Switch from Cursor to Gemini — your agent's memory travels with it.

Key features:

• Cross-platform memory — same memories accessible from any MCP client or ChatGPT via OAuth
• Structured extraction — raw text is automatically parsed into categorized facts with salience scores
• Temporal decay — memories fade naturally by category (skills are evergreen, events fade in 14 days)
• Character scoping — each agent/project gets its own memory namespace
• BYOK AI — bring your own OpenAI, Anthropic, or Gemini key for extraction

Quick Start

1. Get an API Key

Sign up at hippodid.com and create an API key from your dashboard.

2. Download the JAR

Download the latest release from GitHub Releases.

3. Configure Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "hippodid": {
      "command": "java",
      "args": ["-jar", "/path/to/hippodid-mcp-server-1.1.0.jar"],
      "env": {
        "HIPPODID_API_KEY": "hd_key_your_key_here",
        "HIPPODID_CHARACTER_ID": "your-character-uuid"
      }
    }
  }
}

4. Start Using

Ask Claude to remember things, search memories, sync files, and more.

MCP Tools

Tool	Description
create_character	Create a new character to store memories for
list_characters	List all characters accessible to you
add_memory	Add a memory via the AUDN pipeline (rule-based salience + dedup)
add_memory_direct	Write a memory directly, bypassing AUDN pipeline (Starter+ tier)
search_memories	Hybrid semantic + keyword search across memories
sync_file	Sync a local file to the HippoDid cloud
import_document	Import a document and extract memories (Starter+ tier)
list_synced_files	List files synced to the cloud for a character
get_sync_status	Get sync status summary for a character
export_character	Export all memories for a character as Markdown
add_watch_path	Sync a file and register the path for background tracking
list_watch_paths	List all watched file paths in this session
force_sync	Force an immediate sync of all watched paths
configure_ai	Configure tenant BYOK AI providers
test_ai_config	Test connectivity of saved AI provider configuration

Environment Variables

Variable	Required	Default	Description
HIPPODID_API_KEY	Yes	—	Your HippoDid API key
HIPPODID_CHARACTER_ID	No	—	Default character UUID for background sync
HIPPODID_BASE_URL	No	https://api.hippodid.com	API base URL
MCP_SYNC_INTERVAL	No	300	Background sync interval in seconds
MCP_AUTO_CAPTURE	No	false	Disable background watcher (AI handles sync)
MCP_AUTO_RECALL	No	false	Disable background hydration (AI handles download)
MCP_RECALL_CACHE_TTL	No	120	Search result cache TTL in seconds

Architecture

Claude Desktop → stdio (JSON-RPC) → McpServerRunner → HippoDidClient → HTTP → HippoDid REST API

The MCP server uses the hippodid-spring-boot-starter to communicate with the HippoDid REST API over HTTP. All authentication and tenant isolation is handled server-side via Bearer tokens.

Building from Source

Requires Java 21+ and Maven 3.8+.

mvn clean package -DskipTests
java -jar target/hippodid-mcp-server-1.1.0.jar

Versioning

The MCP server version matches the hippodid-spring-boot-starter version. Both must be at the same version for compatibility.

License

Apache License 2.0 — see LICENSE.