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GreyCat
by GreyCat
What GreyCat is
GreyCat is a self-hosted graph database platform that combines time-series, graph, geospatial, vector, and full-text capabilities in one engine. It runs as a self-contained binary on your infrastructure, with a standalone size of approximately 4.6 MB. The Community edition is free forever without a time limit or usage clock and includes role-based access control, token authentication, REST and JSON-RPC APIs, OpenAPI, SDK code generation, a built-in MCP server, and on-device embeddings. AI runs on-device, keeping prompts and documents within the deployment. Pro adds full-text and hybrid search, AI and algebra machine-learning libraries, enterprise connectors, OIDC single sign-on, monitoring, profiling, live and delta backup, and email and priority support. Enterprise adds uptime SLAs, dedicated support, security review, custom terms, and EU-sovereign, on-premises, air-gapped, or BYO-cloud deployment. Community support is available through GitHub and Discord. GreyCat is built by DataThings in Luxembourg.
Who it suits
GreyCat suits teams wanting a self-hosted unified data engine with graph, vector, geospatial, and time-series features. Community is aimed at individuals and teams, while Pro and Enterprise target production and regulated deployments.
What it does well
- Free Community edition forever
- Self-contained approximately 4.6 MB binary
- On-device AI and embeddings
- REST, JSON-RPC, and OpenAPI access
- Role-based access and token authentication
What to know first
- Self-hosted deployment requires your infrastructure
- Advanced search and connectors require Pro
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Community | Self-hosted · Unified time-series, graph, geospatial and vector store · MCP server and OpenAPI · On-device embeddings · REST and JSON-RPC API · RBAC and token authentication | Free |
| Pro | Pro libraries for full-text and hybrid search, AI and algebra ML · Enterprise connectors · OIDC single sign-on · Monitoring and profiler · Live and delta backup · Email and priority support | On request |
| Enterprise | Uptime SLAs · EU-sovereign, on-prem, air-gapped or BYO-cloud deployment · Dedicated support and onboarding · Security review · Custom terms | On request |
As greycat.io lists them, read 28 Sept 2026. The maker's own page has the final word.
Verdict
GreyCat combines several data models and search types while keeping deployment self-contained. Its free Community edition covers core APIs and access controls; higher editions add production operations, connectors, and enterprise deployment options.
Facts from GreyCat's own pages
- Agent support
- A built-in MCP server and OpenAPI support make functions available to AI agents. · greycat.io, 28 Sept 2026
- On-device AI
- AI runs on-device so prompts and documents stay within the deployment. · greycat.io, 28 Sept 2026
- API protocols
- GreyCat provides REST, JSON-RPC, OpenAPI and SDK code generation. · greycat.io, 28 Sept 2026
- Operations tools
- Pro includes monitoring, profiling, live backup and delta backup. · greycat.io, 28 Sept 2026
- Binary size
- The standalone binary is approximately 4.6 MB. · greycat.io, 28 Sept 2026
- Company location
- GreyCat is built by DataThings in Luxembourg, European Union. · greycat.io, 28 Sept 2026
- Database model
- graph · greycat.io, 23 Sept 2026
- Deployment options
- both · greycat.io, 23 Sept 2026
- Enterprise deployment
- Enterprise supports EU-sovereign, on-premises, air-gapped and BYO-cloud deployments. · greycat.io, 28 Sept 2026
- Enterprise identity
- Pro adds OIDC single sign-on. · greycat.io, 28 Sept 2026
- Free edition
- The Community edition is free forever with no time limit or usage clock. · greycat.io, 28 Sept 2026
- Free plan
- Yes · greycat.io, 23 Sept 2026
- Free plan limits
- The page does not state a storage, worker, cache or usage limit for Community. · greycat.io, 28 Sept 2026
- Headquarters
- Luxembourg · greycat.io, 28 Sept 2026
- Enterprise connectors
- Connectors include PostgreSQL, Kafka, OPC-UA, MQTT, S3, SFTP, OpenStreetMap and IFC. · greycat.io, 28 Sept 2026
- Roadmap items
- Many-worlds branching and on-device LLM text generation are listed as planned. · greycat.io, 28 Sept 2026
- Search features
- Pro adds full-text and hybrid search, AI and algebra machine learning libraries. · greycat.io, 28 Sept 2026
- Access control
- Community includes role-based access control and token authentication. · greycat.io, 28 Sept 2026
- Self-hosting
- GreyCat runs as a self-contained binary on the customer's own infrastructure. · greycat.io, 28 Sept 2026
- SQL support
- No · greycat.io, 23 Sept 2026
- Support levels
- Community support is via GitHub and Discord; Pro adds email and priority support. · greycat.io, 28 Sept 2026
- Unified database
- Combines time-series, graph, geospatial, vector and full-text search in one engine. · greycat.io, 28 Sept 2026
- Vector search
- Yes · greycat.io, 23 Sept 2026
Where GreyCat stands on Freedom251
- Database Software#64 of 75