Refedle is a TUI-driven data transformation tool for CSV and JSON files, built with .NET 10 and Terminal.Gui v2. It lets you explore a file interactively, apply column-level transformations, and replay them as a recipe against large files from the command line.

Explore a file and save the transformations as a recipe:

Then replay that recipe from the command line, no UI:

Install

On macOS and Linux, install the latest release with:

curl -fsSL https://raw.githubusercontent.com/Yuta-K19418/Refedle/main/install.sh | sh

This downloads the prebuilt binary for your platform, verifies its SHA-256 checksum against the release's checksums.txt, and installs refedle into the first writable directory among $XDG_BIN_HOME, $HOME/.local/bin, and /usr/local/bin. It never uses sudo.

Then check and update it with:

refedle version      # print the installed version
refedle update       # replace the binary in place with the latest release

refedle update is not available on Windows or for development builds; download a new archive manually instead.

For manual downloads, prebuilt binaries by platform, and OS security warnings, see docs/usage/installation.md.

To build and run from source instead, replace refedle with dotnet run --project src/App -- in the examples below.

Supported Formats

Format	TUI (Tree)	TUI (Table)	CLI batch (apply)
CSV (.csv)	—	✅	✅
JSON Lines (.jsonl)	✅	✅	✅
JSON Array (.json)	✅	via drill-down only	drill-down recipe only
JSON Object (.json)	✅	via drill-down only	drill-down recipe only

Any file extension other than those listed above results in a NotSupportedException.

CSV (.csv) — TUI Table view. No Tree view, since CSV rows have no nested structure to drill into.

JSON Lines (.jsonl) — TUI Tree and Table view (toggle with t), plus full-file aggregation drill-down (see TUI Usage).

JSON Array (.json) — TUI Tree view, with Table view available only via full-file aggregation drill-down (see TUI Usage). In CLI batch mode, supported only when the recipe is drill-down-scoped (see CLI Batch Usage).

JSON Object (.json) — TUI Tree view, with Table view available only via single-node drill-down (see TUI Usage). In CLI batch mode, supported only when the recipe is drill-down-scoped (see CLI Batch Usage).

Usage

refedle [--file <path>] [--recipe <path.yaml>]

Full key bindings and action details: docs/usage/tui.md

What you can do

Rename a column:

Delete a column, or cast its values to a different type (text, whole number, floating point, etc.).

Filter rows by a column condition:

Fill a column with a fixed value — useful for anonymization or masking:

Format timestamp columns into a different date/time format:

Drill down into nested JSON — pick a path and it's aggregated into a table:

See docs/usage/drilldown.md for exact behavior per node type.

Save a recipe (s) to replay every action above against other files from the CLI — see docs/usage/recipes.md.

CLI Batch Usage

refedle apply --input <input> --recipe <recipe.yaml> --output <output>

Replays a saved recipe against a file, no UI. Add --dry-run to preview the plan without writing output.

Supported input/output combinations, drill-down recipe rules, and --dry-run details: docs/usage/cli.md

Project Structure

src/
  App/               TUI (Terminal.Gui v2) and CLI entry point (Program.cs, Cli/)
  Engine/            File I/O (mmap-backed), schema scanning, filtering, actions, recipe (de)serialization
  Generators/        Roslyn incremental source generator for format-agnostic dispatch
tests/
  Refedle.Tests/     Unit tests
  Refedle.E2ETests/  End-to-end tests (real refedle binary, real TUI)
benchmarks/
  Refedle.Benchmarks/  BenchmarkDotNet performance benchmarks
docs/                Design documents and usage guides

Implementation Notes

• File reads use System.IO.MemoryMappedFiles with ArrayPool<byte> buffer reuse; CSV parsing is backed by the Sep library. There is no SIMD/vectorized scanning code in the engine at this time.
• Recipe YAML is a hand-written, AOT-safe reader/writer (no YamlDotNet or reflection-based serialization).
• Error handling favors a Result/Result<T> return type over exceptions on expected failure paths.
• Both App and Engine are configured for Native AOT (PublishAot=true / IsAotCompatible=true) with TreatWarningsAsErrors enabled.

Requirements

• .NET SDK 10.0.201+ (see global.json)

Build & Test

dotnet build
dotnet test

Acknowledgements

Built with Terminal.Gui and Sep, both MIT licensed. See THIRD-PARTY-NOTICES.txt for full license texts.

License

MIT