pgGraph is a PostgreSQL extension written in Rust (via pgrx) that adds high-performance graph query capabilities directly into PostgreSQL. It allows users to model graphs by registering existing relational tables as nodes and edges, building a compressed sparse row (CSR) adjacency index for sub-millisecond traversals, shortest paths, and connected components. The extension exposes SQL functions (`graph.traverse`, `graph.shortest_path`, `graph.search`, `graph.gql`, `graph.cypher`) and supports both openCypher and a subset of GQL for querying property graphs. It integrates deeply with PostgreSQL security (row-level security, multi-tenancy, ACLs), provides resource governance (memory, disk, work unit budgets), and includes a durable projection layer with atomic manifests, delta segments, compaction, and crash recovery. The codebase is structured as a pgrx extension with a Rust core, SQL bootstrap scripts, background workers for build/maintenance jobs, and an extensive test suite including fuzz targets, property-based tests, and heavy integration tests for concurrency, crash recovery, and performance gates.
Morphic is a self-hostable AI answer engine and chat application. In production it streams LLM research results into a rich chat UI: it runs an agentic researcher loop that calls search tools (SearXNG, Tavily, Brave, Exa, Firecrawl), fetches and extracts page content, allocates numbered citations, and emits a JSONL-based 'spec' stream that a generative UI renderer turns into structured cards, grids, headings, buttons, and inline images. Alongside the core chat it ships usage-budget metering, guest/anonymous chat, file uploads to S3-compatible storage, a notes/library feature, feedback collection, model discovery and selection, chat sharing, admin invitations, and an analytics relay that forwards scrubbed PostHog events without exposing authentication tokens.