ULS - FCC Universal Licensing System CLI Tool

A fast, robust command-line tool for querying FCC ULS public data.

Try it online | cargo install uls-cli

Features

• Quick callsign lookups - uls W1AW
• Automatic data updates - Downloads and applies FCC weekly/daily updates
• Local database - SQLite for fast offline queries
• REST API mode - Serve ULS data over HTTP
• Multiple output formats - JSON, CSV, YAML, table

Quick Start

# Install
cargo install uls-cli

# Initialize database with amateur radio data
uls update --service amateur

# Look up a callsign
uls W1AW

# Search by name
uls search --name "ARRL"

# JSON output
uls W1AW --format json

Supported Radio Services

Currently prioritized:

• Amateur Radio (HA/HV) - Full support
• GMRS (ZA) - Full support

Additional FCC radio services are planned for future releases.

Commands

Command	Description
uls <CALLSIGN>	Quick callsign lookup
uls lookup <CALLSIGN>	Detailed license information
uls search	Search by name, location, etc.
uls update	Download/update database
uls stats	Database statistics
uls serve	Start REST API server
uls download	Download FCC files without building database
uls completions <SHELL>	Generate shell completions (bash, zsh, fish, elvish, powershell)

Safe update planning

Automation can inspect the exact FCC source dates that are currently reachable without changing the database:

uls update --service amateur --plan --format json

The versioned uls.update_plan document includes the current weekly and source dates, every exactly reachable source date, the recommended date, observed FCC archive dates, and any gap in the current daily path. The reachable dates may be disjoint when a newer weekly snapshot safely bridges missing daily archives.

After coordinating a common date across services, apply no farther than that date and require the database to reach it:

uls update --service amateur --through 2026-07-23 --format json

An unreachable target is rejected before database initialization or migration. Each imported archive is transactional. If a later archive fails, the command returns an error while retaining only the earlier, valid contiguous prefix.

Configuration

Environment variables:

• ULS_DB_PATH - Database location (default: ~/.uls/uls.db)
• ULS_CACHE_DIR - Download cache (default: ~/.uls/cache)

Building from Source

git clone https://github.com/tgies/uls
cd uls
cargo build --release

Requirements

• Rust 1.88+

Data Sources

This tool uses public data from the FCC Universal Licensing System:

• Weekly databases: Complete snapshots updated each Sunday
• Daily transactions: Incremental updates Monday-Saturday

License

MIT OR Apache-2.0

Contributing

Contributions welcome! Please read the contributing guidelines first.