nordisk/knut

graphar-flight — crate card

Reverse-engineered (from source — verify, don't trust the name)

• One-line pitch: An Apache Arrow Flight SQL service in front of FalkorDB — send Cypher, get Arrow record batches back — plus an optional graph→Iceberg export.
• Does: Runs a Flight SQL server (run_server/run_server_with, ServerOptions, TlsOptions) exposing CypherFlightService, which executes Cypher via FalkorExecutor and returns Arrow. Has a SchemaRegistry, an auth layer (AuthConfig, Authorizer, BasicCredential, Identity), and Cypher→Arrow convert. Feature skade adds export_cypher_to_iceberg/append_arrow_to_iceberg (graph→Iceberg via the skade Iceberg stack, arrow 59, no FFI).
• Key deps: arrow-flight + tonic + prost + futures (Flight SQL transport), graphar + graphar-falkordb (Cypher execution/format), redis, base64, serde_json; optional skade + tempfile (Iceberg export).
• Shape: lib + examples (export-iceberg, export); medium. Modules: server, service, falkor, registry, auth, convert, export, error.
• Observed role in the workspace: The query/serving front door over FalkorDB and the graph→Iceberg bridge. Its skade export is pulled in (feature-gated) by xtask benches and knut-popviz's iceberg target.

Fill in (one line each — only the human knows these)

• Primary consumer(s):
• Why it exists (vs the obvious alternative):
• Hard constraint (airgap / no-C-deps / no-FFI / pure-Rust / etc.):
• Release cadence & independence (rides a parent? own repo someday?):
• Status (production / prototype / experimental / stubbed):
• Must-NOT-change invariant:
• Biggest known gap or TODO:
• Anything a newcomer would get wrong about it: