JSONL Viewer for VSCode

VSCode extension to view JSONL/NDJSON files as interactive tables with SQL-like query support.

Features

📊 Table View: Display JSONL files as formatted tables
🔍 SQL Queries: Filter and sort data using SQL-like syntax
✨ SQL Editor: Syntax highlighting and autocomplete with CodeMirror
📜 Query History: Access previous queries with keyboard navigation
⚡ Virtual Scrolling: Handle large files (10,000+ rows) smoothly
🎨 VSCode Theme: Seamlessly integrates with your VSCode theme
🔗 Line Navigation: Click line numbers to jump to source

Supported File Types

.jsonl (JSON Lines)
.ndjson (Newline Delimited JSON)

Usage

Open a .jsonl or .ndjson file in VSCode
The file will automatically open in the JSONL Viewer
Use the query input to filter and sort data

Query Examples

-- Filter by exact value
SELECT * FROM data WHERE status = 'active'

-- Multiple conditions
SELECT * FROM data WHERE age > 30 AND department = 'Engineering'

-- Pattern matching
SELECT * FROM data WHERE name LIKE '%smith%'

-- Sorting
SELECT * FROM data ORDER BY created_at DESC

-- Pagination
SELECT * FROM data LIMIT 100 OFFSET 50

-- Select specific columns
SELECT name, email, status FROM data

Supported SQL Features

Feature	Syntax
Select all	`SELECT *`
Select columns	`SELECT col1, col2`
Where clause	`WHERE col = 'value'`
Comparison	`=`, `!=`, `<>`, `>`, `>=`, `<`, `<=`
Pattern match	`LIKE '%pattern%'`
List match	`IN ('a', 'b', 'c')`
Logical	`AND`, `OR`, `NOT`
Null check	`IS NULL`, `IS NOT NULL`
Order by	`ORDER BY col ASC/DESC`
Limit	`LIMIT n`
Offset	`OFFSET n`

Note: The table name in FROM clause is ignored. Queries always apply to the current file.

Installation

From Source

# Clone the repository
git clone https://github.com/mametora/vscode-jsonl-viewer.git
cd vscode-jsonl-viewer

# Install dependencies
npm install
cd webview-ui && npm install && cd ..

# Build
npm run build

# Generate test data (optional)
node scripts/generate-test-data.js 10000

# Package (optional)
npx vsce package

Development

Open the project in VSCode
Press F5 to launch the Extension Development Host
Open a .jsonl file to test

Screenshots

Coming soon

Known Limitations

Aggregate functions (COUNT, SUM, AVG, etc.) are not supported
JOIN operations are not supported
Subqueries are not supported

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Commit Message Convention

This project uses Conventional Commits for automated releases.

<type>: <description>

[optional body]

Types:

feat: - New feature (triggers minor version bump)
fix: - Bug fix (triggers patch version bump)
docs: - Documentation changes
chore: - Maintenance tasks
refactor: - Code refactoring
test: - Adding or updating tests

Breaking Changes: Add ! after the type or include BREAKING CHANGE: in the body to trigger a major version bump.

feat!: remove deprecated API
# or
feat: new API

BREAKING CHANGE: old API has been removed

Release Process

Releases are automated using release-please.

Merge PRs with conventional commit messages to master
release-please automatically creates/updates a Release PR
When the Release PR is merged:
- A new GitHub release is created
- The version in package.json is updated
- CHANGELOG.md is generated
- The extension is automatically published to VS Code Marketplace

License

MIT

JSONL Query Viewer

mametora