EJDB

EJDB2 is a single-file database engine that integrates directly into C/C++ applications without external dependencies, making deployment straightforward, as highlighted in its GitHub description.

The JQL query language supports complex filtering, projections, sorting, and collection joins with an XPath-like syntax, detailed in the README with extensive examples for real-world use cases.

Indexes on JSON fields optimize query performance for equality, range, and prefix matching, and the README provides heuristics for when to use indexes versus brute-force scans.

Includes HTTP REST and WebSocket endpoints with token-based authentication, enabling remote database access without additional server setup, as demonstrated in the network API section.