What is a .CapnProto file?
A Cap’n Proto schema defines a fast serialisation format that needs no parsing step.
- Did you know
- Cap’n Proto was made by a Protocol Buffers author to be even faster - no decoding required.
- Cap’n Proto was created by Kenton Varda, who had also been the main author of Google’s Protocol Buffers version 2.
- Its core idea is that data has the same layout in memory and on the wire, so a message can be used straight away with no parsing step.
- What Analyser reads
- Identify and read developer and data-serialisation files: dependency lockfiles (npm/Yarn/pnpm/Cargo/Poetry/Bundler/Composer - locked-package count), binary serialisations (MessagePack, CBOR, BSON, raw Protobuf messages and descriptor sets), Python pickles with a security note, NumPy .npz and Java jar/war/ear archives, IDL schemas (FlatBuffers/Thrift/Cap n Proto/HCL), MATLAB MAT-files, Redis RDB dumps and columnar big-data containers (Apache Arrow/Feather, Parquet, ORC). The JSON supersets JSON5/JSONC/Hjson now open in a full viewer - see Notebooks & data above.
- Depth of analysis
- .CapnProto is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .CapnProto file
- Drag a .CapnProto file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.