dragoman-0.2.4 is not a library.

dragoman

A web server for scholarly metadata with full DOI Resolution and DOI content negotiation. Send a DOI as the URL path; receive a redirect to the landing page or metadata in any supported format depending on the Accept header.

Installation

Prerequisites

Rust 1.75+ (rustup.rs)

Install

cargo install dragoman

This builds a release binary and installs it to ~/.cargo/bin/dragoman. Make sure ~/.cargo/bin is on your PATH (the Rust installer adds this automatically).

Local SQLite database

dragoman can serve metadata directly from a local SQLite database in the commonmeta format, bypassing the live Crossref/DataCite APIs. This dramatically reduces latency and API load for high-traffic deployments.

Database format

The database is a SQLite3 file with a single works table whose columns map one-to-one to the commonmeta v1.0 schema. The id column is the canonical DOI URL (e.g. https://doi.org/10.5281/zenodo.1234). Complex fields (contributors, references, …) are stored as JSON text.

You can build a database from any commonmeta-supported source using the commonmeta CLI.

Running the server

Start

# Default port 3456
dragoman start

# Custom port
dragoman start --port 8080

# With a local database
dragoman start --db /data/commonmeta-2026-06-15.sqlite3

# Write a PID file so the process can be stopped later
dragoman start --pid-file /tmp/dragoman.pid

# All options together
dragoman start --port 8080 --db /data/commonmeta-2026-06-15.sqlite3 --pid-file /tmp/dragoman.pid

Options can also be supplied as environment variables (flags take precedence):

PORT=8080 COMMONMETA_DB=/data/commonmeta-2026-06-15.sqlite3 RUST_LOG=dragoman=debug dragoman start

During development you can use cargo run in place of the installed binary:

# Run from the project root — the sqlite3 file in the root is loaded by filename
cargo run -- start --db commonmeta-2026-06-15.sqlite3

# Or with a full path
cargo run -- start --db /data/commonmeta-2026-06-15.sqlite3

Error: port already in use

If the chosen port is already in use, the server logs an error and exits:

ERROR dragoman: failed to bind  port=3456  error=Address already in use (os error 48)

Choose a different port with --port or stop the process that holds the port.

Database file not found

If the resolved database path does not exist, dragoman logs a warning and starts without a local database, falling back to the live API for all requests:

WARN dragoman: sqlite file not found, running without local database  path=…

To use a local database, place the SQLite file at the platform default path or set COMMONMETA_DB to its location.

Stop

# Stop using the default PID file location (/tmp/dragoman.pid)
dragoman stop

# Stop using a custom PID file
dragoman stop --pid-file /var/run/dragoman.pid

dragoman stop sends SIGTERM to the running process. The server handles the signal gracefully: it finishes in-flight requests and removes the PID file before exiting. Pressing Ctrl-C has the same effect.

CLI reference

dragoman <COMMAND>

Commands:
  start  Start the server (runs in the foreground)
  stop   Stop a running server by sending SIGTERM to its PID file
  help   Print help

dragoman start [OPTIONS]
  -p, --port <PORT>          TCP port to listen on [env: PORT] [default: 3456]
  -d, --db <PATH>            Local commonmeta SQLite3 database [env: COMMONMETA_DB]
      --pid-file <PATH>      Write PID to this file on startup [env: DRAGOMAN_PID_FILE]

dragoman stop [OPTIONS]
      --pid-file <PATH>      PID file to read [env: DRAGOMAN_PID_FILE] [default: /tmp/dragoman.pid]

Environment variables

Variable	Default	Description
`PORT`	`3456`	TCP port to listen on.
`COMMONMETA_DB`	(platform default)	Path to a local commonmeta SQLite3 database. Metadata is served from the database before falling back to the live API. If the file does not exist, a warning is logged and the server starts without a local database. Platform defaults: macOS → `~/Library/Application Support/commonmeta/commonmeta.sqlite3`; Linux → `/var/lib/commonmeta/commonmeta.sqlite3`.
`DRAGOMAN_PID_FILE`	(none)	Path for the PID file written by `start` and read by `stop`.
`RUST_LOG`	`dragoman=info`	Log filter (see `tracing-subscriber`). Use `dragoman=debug` to log per-request cache hits.

Usage

Redirect (HTML / browser)

When the Accept header prefers text/html or is absent, dragoman redirects to the DOI's landing page:

# Follow the redirect
curl -L http://localhost:3456/10.5281/zenodo.1089100

# Inspect the redirect target without following
curl -s -o /dev/null -w "%{redirect_url}" http://localhost:3456/10.5281/zenodo.1089100
# https://zenodo.org/record/1089100

Content negotiation

Send an Accept header to receive metadata instead of a redirect.

BibTeX

curl -H "Accept: application/x-bibtex" \
     http://localhost:3456/10.5281/zenodo.1089100

RIS

curl -H "Accept: application/x-research-info-systems" \
     http://localhost:3456/10.5281/zenodo.1089100

CSL (Citeproc) JSON

curl -H "Accept: application/vnd.citationstyles.csl+json" \
     http://localhost:3456/10.5281/zenodo.1089100

Crossref

curl -H "Accept: application/vnd.crossref+json" \
     http://localhost:3456/10.1016/j.jaci.2019.09.015

Crossref XML

curl -H "Accept: application/vnd.crossref.unixref+xml" \
     http://localhost:3456/10.1016/j.jaci.2019.09.015

DataCite

curl -H "Accept: application/vnd.datacite.datacite+json" \
     http://localhost:3456/10.5281/zenodo.1089100

Schema.org JSON-LD

curl -H "Accept: application/vnd.schemaorg.ld+json" \
     http://localhost:3456/10.5281/zenodo.1089100

InvenioRDM

curl -H "Accept: application/vnd.inveniordm.v1+json" \
     http://localhost:3456/10.5281/zenodo.1089100

Formatted citation

text/x-bibliography accepts optional style= and locale= parameters. Style names come from the CSL style repository; locale codes from the CSL locales repository.

# APA (default)
curl -H "Accept: text/x-bibliography; style=apa" \
     http://localhost:3456/10.5281/zenodo.1089100

# Vancouver in French
curl -H "Accept: text/x-bibliography; style=vancouver; locale=fr-FR" \
     http://localhost:3456/10.5281/zenodo.1089100

Query parameter overrides

Use ?format= instead of an Accept header:

curl "http://localhost:3456/10.5281/zenodo.1089100?format=bibtex"
curl "http://localhost:3456/10.5281/zenodo.1089100?format=citation&style=apa&locale=de-DE"

Supported formats

Accept header	`?format=` value	Notes
`application/x-bibtex`	`bibtex`
`text/x-bibliography`	`citation`	`style=` and `locale=` params
`application/vnd.commonmeta+json`	`commonmeta`
`application/vnd.crossref+json`	`crossref`
`application/vnd.crossref.unixref+xml`	`crossref_xml`
`application/vnd.crossref.unixsd+xml`	`crossref_xml`	alias
`application/vnd.citationstyles.csl+json`	`csl`
`application/vnd.datacite.datacite+json`	`datacite`
`application/vnd.datacite.datacite+xml`	`datacite_xml`
`application/vnd.inveniordm.v1+json`	`inveniordm`
`application/x-research-info-systems`	`ris`
`application/vnd.schemaorg.ld+json`	`schemaorg`
`text/html` / (absent)	—	307 redirect to landing page

HTTP status codes

Code	Meaning
200	Metadata returned
307	Redirect to landing page
404	DOI not found
406	Requested content type not supported
502	Upstream API error

Deployment (macOS)

Installation via Homebrew

dragoman can be installed from the front-matter Homebrew tap:

brew tap front-matter/tap
brew install dragoman

This builds dragoman from source (requires Rust, installed automatically as a build dependency) and places the binary at $(brew --prefix)/bin/dragoman.

Place the database

The platform default path on macOS is ~/Library/Application Support/commonmeta/commonmeta.sqlite3. Place the database there and no further configuration is needed:

mkdir -p "$HOME/Library/Application Support/commonmeta"
cp commonmeta.sqlite3 "$HOME/Library/Application Support/commonmeta/commonmeta.sqlite3"

To use a different path, set COMMONMETA_DB in the launchd plist or pass --db on the command line.

Run as a background service (launchd)

# Start at login and keep alive
brew services start dragoman

# Check status
brew services info dragoman

# View logs
tail -f "$(brew --prefix)/var/log/dragoman.log"

# Stop the service
brew services stop dragoman

brew services start installs a launchd plist in ~/Library/LaunchAgents/ and starts the service immediately. It restarts automatically on crash and at login.

To run as a system-level daemon (starts at boot, not tied to a user login), use sudo brew services start dragoman. This installs the plist in /Library/LaunchDaemons/ instead.

Configuration

To change the port or other settings, edit the service environment variables and restart:

# Open the generated plist for editing
open "$(brew --prefix)/opt/dragoman/homebrew.mxcl.dragoman.plist"
brew services restart dragoman

Manual installation (without Homebrew)

# Install Rust if not already installed
curl https://sh.rustup.rs -sSf | sh

cargo install dragoman
sudo install -m 755 ~/.cargo/bin/dragoman /opt/homebrew/bin/dragoman

Intel Macs: replace /opt/homebrew with /usr/local in all paths below.

Run as a launchd daemon

The bundled com.front-matter.dragoman.plist targets Apple Silicon paths.

sudo mkdir -p /opt/homebrew/var/dragoman /opt/homebrew/var/log
sudo cp commonmeta.sqlite3 /opt/homebrew/var/dragoman/commonmeta.sqlite3

sudo cp com.front-matter.dragoman.plist /Library/LaunchDaemons/
sudo launchctl load -w /Library/LaunchDaemons/com.front-matter.dragoman.plist

Check logs:

tail -f /opt/homebrew/var/log/dragoman.log

Stop and disable:

sudo launchctl unload -w /Library/LaunchDaemons/com.front-matter.dragoman.plist

Updating

With Homebrew

brew upgrade dragoman
brew services restart dragoman

Manual

cargo install dragoman
sudo install -m 755 ~/.cargo/bin/dragoman /opt/homebrew/bin/dragoman
sudo launchctl kickstart -k system/com.front-matter.dragoman

Deployment (Debian / systemd)

This section covers running dragoman as a persistent system service on a Debian 13 server.

1. Build the binary

On the server, install Rust and install the binary:

curl https://sh.rustup.rs -sSf | sh
source ~/.cargo/env
cargo install dragoman
sudo install -m 755 ~/.cargo/bin/dragoman /usr/local/bin/dragoman

Or cross-compile locally and copy the binary:

# macOS → Linux x86-64 (requires cross)
cargo install cross
cross build --release --target x86_64-unknown-linux-gnu
scp target/x86_64-unknown-linux-gnu/release/dragoman user@server:/tmp/dragoman
ssh user@server 'sudo install -m 755 /tmp/dragoman /usr/local/bin/dragoman'

2. Create system user and directories

sudo useradd --system --no-create-home --shell /usr/sbin/nologin dragoman
sudo mkdir -p /var/lib/commonmeta /etc/dragoman
sudo chown dragoman:dragoman /var/lib/commonmeta

3. Place the SQLite database

The platform default path on Linux is /var/lib/commonmeta/commonmeta.sqlite3. Place the database there and no further configuration is needed:

sudo cp commonmeta.sqlite3 /var/lib/commonmeta/commonmeta.sqlite3
sudo chown dragoman:dragoman /var/lib/commonmeta/commonmeta.sqlite3

To use a different path, set COMMONMETA_DB in the environment file instead.

4. Create the environment file

sudo tee /etc/dragoman/env > /dev/null <<'EOF'
PORT=3456
RUST_LOG=dragoman=info
EOF
sudo chmod 640 /etc/dragoman/env
sudo chown root:dragoman /etc/dragoman/env

5. Install and enable the systemd unit

sudo cp dragoman.service /etc/systemd/system/dragoman.service
sudo systemctl daemon-reload
sudo systemctl enable --now dragoman

Check the service is running:

sudo systemctl status dragoman
sudo journalctl -u dragoman -f

Updating the binary

cargo install dragoman
sudo install -m 755 ~/.cargo/bin/dragoman /usr/local/bin/dragoman
sudo systemctl restart dragoman

Updating the database

The database file can be replaced while the service is running. dragoman opens the SQLite file once at startup; to pick up a new file, restart the service:

sudo cp commonmeta-new.sqlite3 /var/lib/commonmeta/commonmeta.sqlite3
sudo chown dragoman:dragoman /var/lib/commonmeta/commonmeta.sqlite3
sudo systemctl restart dragoman

Reverse proxy

Caddy (standalone)

Caddy is the recommended reverse proxy for standalone deployments. It handles TLS certificates automatically via Let's Encrypt.

sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https curl
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' \
  | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' \
  | sudo tee /etc/apt/sources.list.d/caddy-stable.list
sudo apt update && sudo apt install caddy

Add a site block to /etc/caddy/Caddyfile:

doi.example.com {
    reverse_proxy localhost:3456
}

Reload Caddy:

sudo systemctl reload caddy

Traefik via Coolify

If the server already runs Coolify, its Traefik instance can route directly to the dragoman systemd service. Add a file-provider config to the Coolify dynamic configuration directory:

sudo tee /data/coolify/proxy/dynamic/dragoman.yml > /dev/null <<'EOF'
http:
  routers:
    dragoman:
      rule: "Host(`doi.example.com`)"
      service: dragoman
      entryPoints:
        - https
      tls:
        certResolver: letsencrypt
  services:
    dragoman:
      loadBalancer:
        servers:
          - url: "http://host.docker.internal:3456"
EOF

Traefik picks up the file automatically — no reload needed. host.docker.internal resolves to the host from inside the Traefik container; dragoman must listen on all interfaces (0.0.0.0:3456, which is the default).

License

MIT

dragoman 0.2.4