| 1 | # jv |
| 2 | |
| 3 | A native desktop JSON viewer with intelligent schema inference, cross-file comparison, and code generation. |
| 4 | |
| 5 | Built with Rust and [egui](https://github.com/emilk/egui) for native performance — no Electron, no web runtime. Themed with Catppuccin Mocha. |
| 6 | |
| 7 | ## Install |
| 8 | |
| 9 | jv releases prebuilt binaries in github. |
| 10 | |
| 11 | ### One Liner Install |
| 12 | |
| 13 | Uses curl to download prebuilt binary into `~/.local/jv` and symlinks |
| 14 | `~/.local/bin/jv` to `~/.local/jv/bin/jv`. This can also be used for updating |
| 15 | to latest version. |
| 16 | |
| 17 | ```bash |
| 18 | curl https://raw.githubusercontent.com/huncholane/jv/refs/heads/main/install | sh |
| 19 | ``` |
| 20 | |
| 21 | Remember to add `~/.local/bin` to the path. |
| 22 | |
| 23 | ```bash |
| 24 | export PATH="$PATH:$HOME/.local/bin" |
| 25 | ``` |
| 26 | |
| 27 | ## Features |
| 28 | |
| 29 | ### Four Modes |
| 30 | |
| 31 | - **Jv** — Browse individual JSON files with a tree view, table view, and jq filter execution |
| 32 | - **Schema** — Interactive entity relationship diagram showing inferred structs and their connections across files |
| 33 | - **Groups** — Miller-column view grouping common structures and strings across loaded files |
| 34 | - **Code** — Auto-generated Rust and Swift struct definitions with proper serde/Codable attributes |
| 35 | |
| 36 | ### Smart Schema Inference |
| 37 | |
| 38 | - Detects shared data structures across multiple JSON files using Jaccard similarity on field sets |
| 39 | - Merges similar structs with configurable threshold (default 80%) |
| 40 | - Depluralization and singularization for struct naming |
| 41 | - Handles optional fields, mixed types, and nested objects |
| 42 | |
| 43 | ### File Support |
| 44 | |
| 45 | - JSON files |
| 46 | - HAR (HTTP Archive) files with automatic response body extraction |
| 47 | - Batch directory import |
| 48 | - Toggle individual source files on/off to dynamically rebuild schema |
| 49 | |
| 50 | ### Performance Focused |
| 51 | |
| 52 | - egui's immediate mode rendering keeps the UI snappy even with large JSON files |
| 53 | - Virtual scrolling for long lists — only visible rows are rendered |
| 54 | - Content-based caching with hash keys to avoid redundant recomputation |
| 55 | - No garbage collector, no runtime overhead — just Rust |
| 56 | |
| 57 | ### Session Based |
| 58 | |
| 59 | - Create multiple independent sessions, each with their own set of loaded files and configuration |
| 60 | - Sessions persist across app restarts — reopen and pick up where you left off |
| 61 | - Switch between sessions to compare different datasets side by side |
| 62 | |
| 63 | ### Rich Data Handling |
| 64 | |
| 65 | - Automatic temporal type detection (ISO 8601 dates, times, Unix timestamps) |
| 66 | - Timezone-aware formatting with relative time display |
| 67 | - Enum variant consolidation from string fields |
| 68 | |
| 69 | ## Build |
| 70 | |
| 71 | Requires Rust nightly: |
| 72 | |
| 73 | ```bash |
| 74 | cargo build --release |
| 75 | ``` |
| 76 | |
| 77 | ## Run |
| 78 | |
| 79 | ```bash |
| 80 | cargo run |
| 81 | ``` |
| 82 | |
| 83 | Or after building: |
| 84 | |
| 85 | ```bash |
| 86 | ./target/release/jv |
| 87 | ``` |
| 88 | |
| 89 | ## Private Tests |
| 90 | |
| 91 | Tests in `tests/private/` are gitignored so contributors can write tests against their own JSON/HAR data without risking exposing personal or proprietary information to the repository. The test files are included into the main test suite via `include!()` macros — they compile and run locally but never get committed. |
| 92 | |
| 93 | To use private tests, add `.json` or `.har` files to `samples/private/` and write test functions in `tests/private/`. Both directories are gitignored. |
| 94 | |
| 95 | ## Dependencies |
| 96 | |
| 97 | |
| 98 | |
| 99 | | `eframe` / `egui` 0.31 | Native desktop UI framework | |
| 100 | | `egui_extras` | Syntax highlighting, images, SVGs | |
| 101 | | `egui-phosphor` | Icon font | |
| 102 | | `serde_json` | JSON parsing | |
| 103 | | `jaq-*` | jq query language execution | |
| 104 | | `chrono` / `chrono-tz` | Temporal types with timezone support | |
| 105 | | `rfd` | Native file dialogs | |
| 106 | | `walkdir` | Directory traversal | |
| 107 | |
| 108 | ## License |
| 109 | |
| 110 | MIT |
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