Lantern

Lantern is a local-first network intelligence workspace. It correlates devices, services, names, ownership, and routes into an interactive 3D map that you can revisit to see how a network changes over time.

Nmap supplies active discovery, but it is only one part of the observation pipeline. Lantern combines its results with local service discovery, DNS, internet registry data, and route topology, while preserving the supporting evidence in SQLite on your machine.

Features

• Correlated host discovery from active Nmap scans and local mDNS/DNS-SD advertisements
• Port, service, product, OS, hostname, and MAC vendor evidence for each observed host
• Native HTTPS certificate inspection with certificate-derived hostname evidence
• Reverse DNS and public network profiles from RDAP with WHOIS field fallback
• Route topology from MTR or traceroute, rendered alongside hosts in 3D
• Address-space, route-map, and multi-observation temporal views
• Background and concurrent observations with live progress, tool activity, logs, and cancellation
• Built-in scan profiles plus safely parsed custom Nmap arguments
• Provider discovery, selection, fallback, and per-provider evidence history
• Local SQLite persistence in a single binary with the web interface embedded

Requirements

• macOS or Linux
• Nmap on PATH
• A WebGL-capable browser

Optional:

• mtr or traceroute for route mapping
• whois for fallback public network ownership details; Lantern uses RDAP by default
• avahi-browse on Linux for local mDNS/DNS-SD advertisements; macOS uses the built-in dns-sd

Build and run

Building requires Go 1.25+, Node.js 22.12+ or 20.19+, npm, and Make.

git clone https://github.com/erniebrodeur/lantern.git
cd lantern
make build
./bin/lantern

The frontend is compiled and embedded into bin/lantern. Open http://127.0.0.1:1414.

Usage

Start a previously built Lantern binary:

./bin/lantern

Show the compiled version:

./bin/lantern --version

An observation runs several tools as one coordinated job. Nmap actively finds hosts and services while the platform's DNS-SD provider listens for advertised local services. Observed addresses are enriched with reverse DNS and, for public networks, RDAP and WHOIS registration data. Selecting the Map view adds route evidence through MTR or traceroute when either is installed.

Provider results, progress, and logs remain attached to the observation instead of being flattened into a one-time scan report.

Lantern includes four scan profiles:

• Discovery — host discovery only
• Quick — top 100 TCP ports with light service detection
• Standard — top 1,000 TCP ports with service detection
• Deep — all TCP ports with full version probing

Custom profile arguments can be edited in the scan bar. Lantern's Nmap provider owns the target, XML output, and progress arguments and executes without a shell.

OS detection requires a privileged launch:

sudo ./bin/lantern

When launched through sudo, Lantern continues to use the invoking user's database and defaults OS detection on.

Configuration

Variable	Default
LANTERN_ADDR	127.0.0.1:1414
LANTERN_DB_PATH	~/.lantern/lantern.db
LANTERN_NMAP_PATH	nmap
LANTERN_MDNS_PROVIDER	OS default (dns-sd on macOS, avahi on Linux)
LANTERN_OWNERSHIP_PROVIDER	RDAP with WHOIS field fallback
LANTERN_ROUTE_PROVIDER	mtr, then traceroute
LANTERN_WHOIS_PATH	whois

Example:

LANTERN_ADDR=127.0.0.1:1515 \
LANTERN_DB_PATH=/tmp/lantern.db \
./bin/lantern

Lantern binds to loopback by default. It is not intended to be exposed directly to the internet.

Provider selection and availability are reported by /api/capabilities. Set LANTERN_<CAPABILITY>_PROVIDER=disabled to disable a capability, or set it to a provider ID to pin one implementation. Hyphens become underscores; for example, LANTERN_REVERSE_DNS_PROVIDER=disabled disables PTR lookups.

Public-address enrichment sends the queried address over HTTPS to RDAP.org, which redirects to the authoritative regional registry. Set LANTERN_OWNERSHIP_PROVIDER=disabled to prevent external ownership lookups.

Data

Scan history, profiles, host observations, services, OS matches, and saved routes are stored in SQLite:

~/.lantern/lantern.db

Stop Lantern before backing up the database so SQLite can reconcile its WAL.

License

Lantern is licensed under the GNU General Public License v3.0.

Development

make check

make check builds the frontend, runs the Go test suite, and runs go vet.

Generate a Go coverage profile and a browsable, line-by-line HTML report:

make coverage
open coverage.html # use xdg-open on Linux

Both make check and make coverage require at least 80% statement coverage in every executable Go source file.

For frontend development:

npm --prefix web ci
npm --prefix web run dev

Vite proxies API requests to the Go server on 127.0.0.1:1414.

If you have any issues, please open a GitHub issue.