Hydra DB — MCP Server

MCP (Model Context Protocol) server for Hydra DB, the state-of-the-art agentic memory. Provides tools for storing, recalling, and managing memories with knowledge-graph enriched context.

Available Tools

hydra_db_search

Search through Hydra DB memories. Returns relevant chunks with graph-enriched context including entity paths and knowledge graph relations.

Parameter	Type	Required	Description
query	string	Yes	The search query to find relevant memories
max_results	number	No	Maximum number of memory chunks to return (1-50, default: 10)
mode	string	No	Recall mode: fast for quick semantic search, thinking for deeper personalised recall with graph traversal (default: thinking)
graph_context	boolean	No	Whether to include knowledge graph relations in results (default: true)

hydra_db_store

Save important information to Hydra DB memory. Hydra DB automatically extracts insights, preferences, and builds a knowledge graph from the stored content. Supports plain text and markdown.

Parameter	Type	Required	Description
text	string	Yes	The information to store in memory
title	string	No	Title for the memory entry (default: MCP Memory)
source_id	string	No	Source identifier to group related memories together (e.g. session ID)
infer	boolean	No	Whether Hydra DB should extract insights and build knowledge graph (default: true)
is_markdown	boolean	No	Whether the text is in markdown format (default: false)

hydra_db_ingest_conversation

Ingest user-assistant conversation turns into Hydra DB memory. Hydra DB extracts insights, preferences, and knowledge graph entities from the conversation.

Parameter	Type	Required	Description
turns	array	Yes	Array of conversation turns, each with a user and assistant field
source_id	string	Yes	Source identifier to group all turns from the same session together
user_name	string	No	Name of the user for personalisation (default: User)

hydra_db_list_memories

List all stored user memories in Hydra DB. Returns memory IDs and their content. No parameters required.

hydra_db_delete_memory

Delete a specific user memory from Hydra DB by its memory ID. This action is irreversible.

Parameter	Type	Required	Description
memory_id	string	Yes	The ID of the memory to delete

hydra_db_fetch_content

Fetch the full content of a specific source by its source ID.

Parameter	Type	Required	Description
source_id	string	Yes	The source ID to fetch content for
mode	string	No	Fetch mode: content for text, url for presigned URL, both for both (default: content)

hydra_db_list_sources

List all ingested sources in Hydra DB memory. Returns source IDs, titles, types, and metadata.

Parameter	Type	Required	Description
source_ids	array	No	Array of specific source IDs to filter by. If omitted, lists all sources

Configuration

Get Your Credentials

1. Get your Hydra DB API Key from Hydra DB
2. Get your Tenant ID from the Hydra DB dashboard

Environment Variables

Variable	Description	Default
HYDRA_DB_API_KEY	Your Hydra DB API key	Required
HYDRA_DB_TENANT_ID	Your Hydra DB tenant identifier	Required
HYDRA_DB_SUB_TENANT_ID	Sub-tenant for data partitioning	hydra-db-mcp
HYDRA_DB_LOG_LEVEL	Log level: DEBUG, INFO, WARN, ERROR	ERROR

Claude Desktop

{
  "mcpServers": {
    "hydradb": {
      "command": "npx",
      "args": ["-y", "@hydradb/mcp@latest"],
      "env": {
        "HYDRA_DB_API_KEY": "your-api-key",
        "HYDRA_DB_TENANT_ID": "your-tenant-id"
      }
    }
  }
}

Cursor & Windsurf

Client	Config File
Cursor	~/.cursor/mcp.json
Windsurf	~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "hydradb": {
      "command": "npx",
      "args": ["-y", "@hydradb/mcp@latest"],
      "env": {
        "HYDRA_DB_API_KEY": "your-api-key",
        "HYDRA_DB_TENANT_ID": "your-tenant-id"
      }
    }
  }
}

VS Code

Add to .vscode/mcp.json:

{
  "servers": {
    "hydradb": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@hydradb/mcp@latest"],
      "env": {
        "HYDRA_DB_API_KEY": "your-api-key",
        "HYDRA_DB_TENANT_ID": "your-tenant-id"
      }
    }
  }
}

Custom Sub-Tenant

To partition data, set the HYDRA_DB_SUB_TENANT_ID environment variable:

{
  "mcpServers": {
    "hydradb": {
      "command": "npx",
      "args": ["-y", "@hydradb/mcp@latest"],
      "env": {
        "HYDRA_DB_API_KEY": "your-api-key",
        "HYDRA_DB_TENANT_ID": "your-tenant-id",
        "HYDRA_DB_SUB_TENANT_ID": "my-project"
      }
    }
  }
}

How It Works

• hydra_db_search queries POST /recall/recall_preferences for relevant memories and returns graph-enriched context (entity paths, chunk relations, extra context). Supports fast and thinking recall modes.
• hydra_db_store sends text to POST /memories/add_memory with configurable infer, upsert, is_markdown, title, and source_id options. Hydra DB extracts insights and builds a knowledge graph automatically.
• hydra_db_ingest_conversation sends user-assistant pairs to POST /memories/add_memory as conversation turns, grouped by source_id.
• hydra_db_list_memories queries POST /list/data (kind: memories) to browse stored memories.
• hydra_db_list_sources queries POST /list/data (kind: knowledge) to browse ingested sources, with optional source_ids filter.
• hydra_db_delete_memory calls DELETE /memories/delete_memory to remove a specific memory.
• hydra_db_fetch_content calls POST /fetch/content to retrieve the original ingested content, with mode options (content, url, or both).

Development

npm ci
npm run build
HYDRA_DB_API_KEY=your-key HYDRA_DB_TENANT_ID=your-tenant npm start

For development with auto-reload:

HYDRA_DB_API_KEY=your-key HYDRA_DB_TENANT_ID=your-tenant npm run dev

Testing

# unit tests (mocked HTTP)
npm test

# live integration test against Hydra DB
RUN_LIVE_TESTS=true HYDRA_DB_API_KEY=your-key HYDRA_DB_TENANT_ID=your-tenant npm run test:integration

Troubleshooting

• API Key Issues: Ensure HYDRA_DB_API_KEY is set correctly
• Connection Errors: Check your internet connection and API key validity
• Tool Not Found: Make sure the package is installed and the command path is correct
• Debug Logging: Set HYDRA_DB_LOG_LEVEL=DEBUG for verbose output

Contributing / Developer Setup

Get up and running quickly with the bootstrap script:

git clone https://github.com/usecortex/hydradb-mcp.git
cd hydradb-mcp
make bootstrap

This will install dependencies, build the project, and create a .env file from .env.example. Edit .env with your HydraDB credentials, then:

make dev          # Start MCP server in dev mode (auto-reload)
make test         # Run unit tests
make test-all     # Run unit + integration tests
make check-types  # Type-check without emitting

Run make help to see all available targets.