FBS
Generated by scripts/gen-format-pages.py from docs/data/format-metadata/, FILE_FORMATS.csv and docs/formats-master.csv. Do not edit by hand: change the source, then run the script.
FlatBuffers Schema Preview.
At a glance
| Purpose | A FlatBuffers schema: tables, structs, enums, unions and RPC services that define a zero-copy serialisation format. |
| Extensions | .fbs |
| Poka parser | poka-fbs |
| Viewer | poka-tree-viewer |
| Depth tier | Parser with a shared viewer (see Depth tiers) |
| Breadth tier | B2 Broad (see Breadth tiers) |
How much Poka reads
B2 Broad. The common content of the current and the common older versions is decoded. Some named features or versions are not, and are listed.
Confidence: medium (the reviewer read the code). Basis: Reviewed 2026-10-26: read parsers/poka-fbs/src/main.rs (1046 lines, a brace- and comment-aware scanner) and plugin.json. No unit tests or tests/samples.rs; the corpus has flatbuffers_monster.fbs but no test reads it. Covers .fbs. The tree has namespace, includes, root_type, file_identifier and file_extension, and every table and struct with fields (type and default), enums with underlying type and values, unions with members and rpc_service methods with argument and return types.
What Poka does not read
- Field and type attributes ((deprecated), (id: n), (required), (key) and the like) are stripped
- Doc comments (///) are stripped with the other comments
- attribute declarations are skipped
- Includes are listed but not followed
- Files over 32 MiB are cut without a flag; caps of 200 definitions, 200 members each, 64 includes and 3,000 nodes
Libraries
Libraries Poka uses or has assessed for this format, with the status, licence and language the registry records.
- flatc / flatbuffers (candidate; Apache-2.0; C++; https://github.com/google/flatbuffers/blob/master/src/idl_parser.cpp) — Official schema compiler; idl_parser.cpp is the .fbs parser. Rust use means calling flatc, not a Rust library.
- planus (candidate; MIT OR Apache-2.0; Rust; https://github.com/planus-org/planus) — Alternative FlatBuffers compiler in Rust with separate parse and validate stages; some schema features unsupported (rpc_service, fixed-size arrays).
Sources
- parsers/poka-fbs/src/main.rs
- parsers/poka-fbs/plugin.json