API Tester (Rust + egui)

A lightweight, fast native GUI tool to test and visualize REST APIs. It targets JSON payloads up to around 1 MB (handled with serde) and focuses on dense information display, inline structural diffs, and powerful querying (JSONPath/JMESPath).

This repository ships a GitHub Actions workflow: pushing a Git tag like v0.1.0 triggers a multi‑OS build and publishes downloadable binaries to GitHub Releases automatically.

Features

• HTTP methods: GET / POST / PUT / PATCH / DELETE
• Background request execution (prevents UI freeze)
• Authentication: None / Basic / Bearer / OAuth2 Token
• Header editor (one per line: Key: Value)
• Request Body:
  • JSON editor (pretty-printed)
  • Form key=value editor with compact rows (+Add, delete, enable/disable)
  • Bidirectional sync between JSON and Form (always consistent)
• Response display:
  • Tree view with collapsible Object/Array nodes
  • Scrollable area for large payloads
  • Status colorization (200=green, 3xx/others=yellow, 4xx/5xx=red)
• Diff (mandatory requirement):
  • Structural diff using json_patch::diff applied inline to the Tree
  • For replaced nodes, show current value with the old value in gray beside it
• Query (always applied to the Tree view):
  • JSONPath (extraction)
  • JMESPath (extraction + transformation)
  • Press Run to apply the result directly as the Tree content
• Search (plain text): list matching pretty‑JSON lines with line numbers
• Profiles management (project/folder based):
  • Stored at ./profiles/<project>/<profile>.json
  • Folder-like explorer UI (projects as folders, profiles as files)
  • New / Save / Overwrite / Load / Delete / Rename (for both projects and profiles)
• cURL import: basic parsing for method/url/headers/body
• Export: JSON, NDJSON (for arrays), CSV (flattened arrays of objects)
• Auto polling: periodically send requests; inline diff highlights changes
• Window Always‑on‑Top toggle (Float/Unfloat)
• Compact UI (tight spacing and font size)

Screenshot

Usage

1. Set the URL and HTTP method.
2. Optionally edit Auth/Headers/Body.
   • Body can be switched between JSON and Form; both stay in sync.
3. Click Send; the request is executed in a background thread.
4. Inspect JSON in the Tree view (inline diff and old values are shown automatically).
5. Enter JSONPath or JMESPath in the Query section and hit Run; the Tree shows the filtered result.
6. Manage projects/profiles in the Profiles explorer (double‑click to load).
7. Use Export to save JSON/NDJSON/CSV.

Install

• Download the archive for your OS from GitHub Releases and extract it.
  • Example: api-tester-v0.1.0-windows-x86_64.tar.gz
• On Windows, the MSVC runtime might be required. If the app does not start, install the Visual C++ Redistributable.

Automatic release (GitHub Actions via tags)

This repo contains .github/workflows/release.yml. Pushing a tag that matches v* will trigger CI.

Steps:

# Commit your changes
git add -A
git commit -m "chore: prepare v0.1.0"

# Create a tag
git tag v0.1.0

# Push the tag
git push origin v0.1.0
# or
# git push origin --tags

CI pipeline:

• Build release binaries on Windows / Linux / macOS
• Package the binary (and README / LICENSE / docs/sample.json if present) into an archive
• Generate SHA256 checksums
• Upload the assets to the corresponding GitHub Release

Note: The package name in Cargo.toml is API-tester. The workflow detects the actual binary name robustly (case/hyphen differences handled).

Build from source

Ensure Rust stable is installed, then:

cargo build --release

Artifacts:

• Windows: target\release\API-tester.exe
• Linux/macOS: target/release/API-tester

Tech stack

• GUI: eframe/egui (native)
• HTTP: reqwest (blocking)
• JSON: serde/serde_json
• Diff: json-patch (structural, mandatory), similar (text diff)
• Query: jsonpath_lib / jmespath
• Others: rfd (file dialogs), url, base64, csv, anyhow

Roadmap

• Hints in the tree to make removed nodes (JSON Patch remove) discoverable
• Virtualized scrolling/pagination for very large arrays
• Additional auth flows (OAuth2 Code Flow)

License

This project is licensed under the MIT License. See the LICENSE file at the repository root.

Third-party dependencies are licensed under permissive terms (MIT, Apache-2.0, Unlicense). A summary is available in THIRD_PARTY_LICENSES.md. For crates under Apache-2.0, the full Apache License text is included in LICENSE-APACHE-2.0.

Translations

• Japanese documentation: jp/README.md and jp/CHANGELOG.md

Changelog

See CHANGELOG.md.