Neptune
A fully managed graph database service from AWS supporting both property graph and RDF models. Available as Neptune Database (for transactional workloads) and Neptune Analytics (for analytical queries).
- Overall rank
- #4
- First released
- November 2017
- License
- Proprietary
- Built with
- C++
Sources 10 references
Protocols Bolt, Gremlin (WebSocket), Gremlin (HTTP), SPARQL Protocol, HTTP/REST
Bolt is TCP-only on Neptune (the WebSocket variant of the spec is not supported); Gremlin has both a WebSocket driver channel and a separately documented HTTPS REST endpoint; SPARQL is served over its own 1.1 Protocol HTTP endpoint. Kept HTTP/REST because it is independently justified by the openCypher HTTPS endpoint (a generic REST channel with no more specific vocabulary tag) and by the separate Loader/management HTTP API, not just as a stand-in for SPARQL or Gremlin. Rejected pass_B's drop of Gremlin (HTTP) and HTTP/REST.
-
Neptune provides a Gremlin endpoint (HTTPS and WebSocket), openCypher endpoint (HTTPS and Bolt), and a SPARQL 1.1 Protocol REST endpoint
Managed Graph Database – Amazon Neptune FAQs – AWS · reviewed 2026-08-02 -
Althought the Bolt spec states that Bolt can connect using either TCP or WebSockets, Neptune only supports TCP connections for Bolt.
Using the Bolt protocol to make openCypher queries to Neptune · reviewed 2026-08-02 -
If you use a Gremlin language variant to query Neptune, the driver connects to the database using a WebSocket connection.
Managing Gremlin WebSocket connections in AWS Lambda functions · reviewed 2026-08-02 -
Amazon Neptune provides an HTTPS endpoint for Gremlin queries. The REST interface is compatible with whatever Gremlin version your DB cluster is using
Using the HTTPS REST endpoint to connect to a Neptune DB instance · reviewed 2026-08-02 -
Amazon Neptune provides an HTTP endpoint for SPARQL queries. The REST interface is compatible with SPARQL version 1.1.
Using the HTTP REST endpoint to connect to a Neptune DB instance · reviewed 2026-08-02 -
Neptune does not currently support HTTP/2 for REST API requests. Clients must use HTTP/1.1 when connecting to endpoints.
The Amazon Neptune OpenCypher HTTPS endpoint · reviewed 2026-08-02
License Proprietary
Neptune is a closed-source, fully managed AWS commercial service with no published source code or license file, so it is classified as Proprietary rather than under any open-source SPDX id.
-
Amazon Neptune is AWS's new fast, reliable, and fully managed graph database service that makes it easy for developers to build and run applications that work with highly connected datasets.
AWS Announces New Capabilities for Amazon Aurora and Amazon DynamoDB, Introduces Amazon Neptune Graph Database · reviewed 2026-08-02
Released 2017-11
Matches current value; a limited preview was launched at re:Invent on November 29, 2017, well ahead of the May 2018 general availability.
-
Today we're launching a limited preview (sign up here) of Amazon Neptune, a fast and reliable graph database service that makes it easy to gain insights from relationships among your highly connected datasets.
Amazon Neptune – A Fully Managed Graph Database Service | AWS News Blog · reviewed 2026-08-02
Language C++
AWS does not directly disclose Neptune's implementation language. Amazon's own paper on Poseidon, the engine behind Neptune Analytics, describes a C++ template-heavy codebase, and Neptune engineering job postings require C++ (or Rust) proficiency for the storage/compute core, so C++ is the best-supported inference for the primary engine language.
-
For these reasons, our code relies heavily on C++ templates. The templates implement the access patterns as defined and enumerated by the P8APL interface.
Poseidon: A OneGraph Engine · reviewed 2026-08-02 -
1+ years of experience in C++, Rust, Related programming language- Knowledge of database internals, query planning and optimization and/or storage performance and efficiency
Software Development Engineer, Amazon Neptune - Job ID · reviewed 2026-08-02