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HydraDB

Open-source graph database on object storage that gives AI agents connected, stateful context and memory.

Open source

What is HydraDB?

HydraDB is a graph database, released as open source, that runs on top of object storage and targets AI agents that need to follow relationships across documents, chats, code and past decisions. Instead of returning only passages that look similar, it links people, projects and events into one graph so an agent can answer questions such as who owns a project or what is blocking a launch. Query and indexing capacity scale separately from storage, and the engine includes native vector search, so teams can combine graph and vector retrieval. You can self-host it on infrastructure you control, using S3-compatible storage and use existing Neo4j drivers and openCypher queries, or run it on HydraDB Cloud. The cloud plans are Ship at $25 per month minimum usage and Scale at $300 per month minimum usage, plus an Enterprise plan with custom pricing; the open-source edition is described as free forever.

Use cases

  • Give AI agents persistent memory
  • Build a company knowledge graph
  • Serve GraphRAG retrieval
  • Connect docs, chats and code into one graph
  • Replace stitched vector and graph stores
  • Self-host a graph database for AI apps

Who it's for

  • AI engineers
  • Backend developers
  • Agent builders
  • Platform teams

Why use HydraDB

  • Follows relationships between entities, so agents can answer questions that similarity search alone often misses.
  • One layer replaces separate vector, graph, Postgres and filesystem stores for agent context.
  • Open-source and self-hostable, with a managed cloud when you prefer not to run it yourself.
  • Storage and query capacity scale independently, which helps as the graph grows.

HydraDB features

  • Graph database built on object storage
  • Native vector search alongside graph traversal
  • Self-hosting with S3-compatible storage
  • Compatible with Neo4j drivers and openCypher queries
  • Import of graphs from other databases
  • Ontology engine for building graphs from ingested content
  • 100+ app connectors on the Ship and Scale cloud plans
  • Advanced logs and monitoring on cloud plans
  • Python and TypeScript SDKs plus an API
  • Dedicated infrastructure and uptime SLA on Scale

HydraDB integrations

  • Neo4j drivers
  • S3-compatible storage

How to get started with HydraDB

  1. Sign up for HydraDB Cloud or deploy the open-source version on your own infrastructure.
  2. Ingest documents, conversations and other data; the ontology engine builds entities and links.
  3. Query through the API, SDKs or Neo4j-compatible drivers using graph and vector search together.
  4. Feed the retrieved context to your agents and monitor activity in the dashboard.

HydraDB limitations

  • Cloud plans carry a monthly minimum usage of $25 (Ship) or $300 (Scale)
  • Self-hosted use comes with community support only
  • Aimed at engineers building their own context layer, not at non-technical users

HydraDB pricing

HydraDB is open source, so you can use and self-host it for free. Paid plans start at $25 per month, according to the official pricing page on .

HydraDB plans

  • Open Source

    Free

    • Self-host on your own infrastructure
    • S3-compatible storage
    • Neo4j drivers and openCypher queries
    • Import graphs from other databases
    • Community support
  • Ship

    $25/mo

    minimum usage

    • Fully managed on HydraDB Cloud
    • Storage: $0.50/GB-month
    • Ontology engine: $5 per 1M tokens ingested
    • 100+ app connectors
    • Advanced logs and monitoring
  • Scale

    $300/mo

    minimum usage

    • Everything in Ship
    • Dedicated infrastructure
    • Storage: $0.25/GB-month
    • Uptime SLA
    • Private Slack channel
    • SOC 2 and GDPR
  • Enterprise

    Custom

    • Deploy in your cloud or a dedicated cloud
    • Dedicated forward-deployed engineer
    • 99% uptime SLA
    • HIPAA BAA

Plans as listed on the official pricing page on . Prices can change and may vary by country or exclude tax. Check the official pricing page.

HydraDB alternatives

The main HydraDB alternatives listed on Debuly are Mem0, Zep, Cognee, Context Data, Marvin and OpenViking. The table compares pricing and platforms; order is A–Z.

HydraDB compared with its alternatives
ToolPricingStarting pricePlatforms
HydraDBOpen source$25/moWeb, API, Self-hosted
CogneeFreemium$1, usage-basedWeb, API, Self-hosted, MCP server
Context DataPricing unknown—Self-hosted, Docker, Kubernetes
MarvinOpen source—Python, CLI
Mem0Freemium$19/moAPI, Web, Self-hosted, CLI
OpenVikingOpen source—Linux, macOS, Windows, CLI
ZepFreemium—API
  1. Cognee

    Open-source memory engine for AI agents that combines vector search, knowledge graphs and relational storage, with a hosted cloud.

  2. Context Data

    InterLock proxy that governs what AI agents can read and write in databases, files and APIs, with redaction and approvals.

  3. Marvin

    Open source Python framework from Prefect for getting structured output from LLMs and building agent workflows from tasks and threads.

  4. Mem0

    Memory layer for AI agents and apps, available as an open-source package or a managed platform that keeps user context across sessions.

  5. OpenViking

    Open-source context database for AI agents that stores memory, knowledge and skills as a browsable file system

  6. Zep

    Managed memory and context platform for AI agents, built on the Graphiti knowledge graph, with Python, TypeScript and Go SDKs.

HydraDB FAQ

How much does HydraDB cost?

Ship is $25/mo minimum usage with storage at $0.50/GB-month and ontology building at $5 per 1M tokens ingested. Scale is $300/mo minimum usage with storage at $0.25/GB-month. Enterprise pricing is custom, and the open-source edition is described as free forever.

Is there a free plan for HydraDB?

The open-source edition is free to self-host. The managed HydraDB Cloud plans start with Ship at $25/mo minimum usage.

Is HydraDB open source?

Yes. The vendor announces HydraDB as open source and links to its GitHub repository.

Who is HydraDB for?

Engineers building products that need connected context drawn from emails, chats, docs, transcripts, PDFs, code and memories.

Does HydraDB work with GraphRAG or existing graph tools?

Yes. It can serve as the graph database behind a GraphRAG application, and it supports existing Neo4j drivers and openCypher queries.

What are alternatives to HydraDB?

The vendor compares itself with FalkorDB, Neo4j, Memgraph, Dgraph, Amazon Neptune and ApertureDB, and memory services such as Mem0, Zep and Hyperspell cover related ground.

Sources & verification

Facts on this page come from the official sources below, each with the date we read it. Written by Debuly; the vendor did not review this page.

SourceTypeAccessed
hydradb.com/pricing
hydradb.com/pricingpricing
hydradb.com/blog/hyperspell-alternativesofficial
hydradb.com/blog/graph-databases-real-time-applicationsofficial

Image credits

  • Logo: from framerusercontent.com · fetched · Vendor trademark, used only to identify the product; removed on request
  • Cover: none collected yet, so a generated tile is shown.

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