Cayley

Spec sheet

What it does

Cayley is an open-source graph database inspired by the graph database behind Freebase and Google's Knowledge Graph.Read 4 Oct 2026 · cayley.io

API

Cayley's documentation describes HTTP query endpoints for Gizmo, GraphQL, and MQL.Read 4 Oct 2026 · cayley.gitbook.io

License

Cayley is developed under the Apache 2.0 license and is free to use in any project.Read 4 Oct 2026 · cayley.io

Data size guidance

The guide says the default in-memory store is best for datasets that fit in machine memory and workloads that do not require persistence; it recommends Bolt for large datasets or persistent workloads.Read 4 Oct 2026 · cayley.gitbook.io

Database integrations

The configuration guide lists LevelDB, Bolt, MongoDB, Elasticsearch, CouchDB, PouchDB, PostgreSQL, CockroachDB, MySQL, MariaDB, and SQLite backends.Read 4 Oct 2026 · cayley.gitbook.io

Extensibility

Cayley can be extended with new formats, backends, query languages, or custom logic.Read 4 Oct 2026 · cayley.io

Installation

The installation guide gives instructions for Ubuntu via Snap, macOS via Homebrew, Docker, and building from source.Read 4 Oct 2026 · cayley.gitbook.io

Linked data

Cayley supports RDF and linked data formats including NQuads and JSON-LD.Read 4 Oct 2026 · cayley.io

Query languages

Cayley supports Gizmo, described as a Gremlin dialect, MQL, and a GraphQL dialect.Read 4 Oct 2026 · cayley.io

Query tools

Cayley includes a query editor, visualizer, and REPL.Read 4 Oct 2026 · github.com

Storage

Cayley works on top of SQL, NoSQL, or key-value databases.Read 4 Oct 2026 · cayley.io

Support and community

The project invites users to join its community on Slack or Discourse.Read 4 Oct 2026 · cayley.io

Visualization

The UI overview says the visualizer can display query results as a graph when results are tagged with source and target.Read 4 Oct 2026 · cayley.gitbook.io

Plans and prices

Every Cayley plan and price →

Where Specifiction places it

• Graph Databases#12 of 398.1