easybib 0.3.0

Automatically fetch BibTeX entries from INSPIRE and ADS for LaTeX projects

easybib

Automatically fetch BibTeX entries from INSPIRE and NASA/ADS for LaTeX projects.

easybib scans your .tex files for citation keys, looks them up on INSPIRE and/or ADS, and writes a .bib file with the results. It handles INSPIRE texkeys (e.g. Author:2020abc) and ADS bibcodes (e.g. 2016PhRvL.116f1102A).

Installation

pip install easybib

Usage

easybib /path/to/latex/project
easybib paper.tex

Pass a directory to scan all .tex files recursively, or a single .tex file. BibTeX entries are fetched and written to references.bib.

Options

Flag	Description
-o, --output	Output BibTeX file (default: references.bib)
-s, --preferred-source	Preferred source: ads (default), inspire, or auto
-a, --max-authors	Truncate author lists (default: 3, use 0 for no limit)
-l, --list-keys	List found citation keys and exit (no fetching)
--fresh	Ignore existing output file and start from scratch
--ads-api-key	ADS API key (overrides ADS_API_KEY environment variable)
--config	Path to config file (default: ~/.easybib.config)

Examples

# Scan a directory
easybib ./paper --preferred-source inspire

# Scan a single file
easybib paper.tex

# Use a custom output file
easybib ./paper -o paper.bib

# List citation keys without fetching
easybib ./paper -l

# Keep all authors
easybib ./paper -a 0

Config file

You can create a config file at ~/.easybib.config to set persistent defaults, so you don't have to pass the same flags every time:

[easybib]
output = references.bib
max-authors = 3
preferred-source = ads
ads-api-key = your-key-here

All fields are optional. CLI flags override config file values, which override the built-in defaults.

To use a config file at a different location:

easybib ./paper --config /path/to/my.config

Source selection

The --preferred-source flag controls where BibTeX entries are fetched from. The source determines which service provides the BibTeX data, regardless of the key format used in your .tex files.

• ads (default) — Fetches BibTeX from ADS. If you use an INSPIRE-style key (e.g. Author:2020abc), easybib will cross-reference it via INSPIRE to find the corresponding ADS record, then pull the BibTeX from ADS. Falls back to INSPIRE if ADS lookup fails.
• inspire — Fetches BibTeX from INSPIRE. Falls back to ADS if the INSPIRE lookup fails. Does not require an ADS API key unless the fallback is triggered.
• auto — Chooses the source based on the key format: ADS bibcodes (e.g. 2016PhRvL.116f1102A) are fetched from ADS, while INSPIRE-style keys are fetched from INSPIRE. Falls back to the other source if the preferred one fails.

ADS API key

When using ADS as the source (the default), provide your API key either via the command line:

easybib ./paper --ads-api-key your-key-here

Or as an environment variable:

export ADS_API_KEY="your-key-here"

Get a key from https://ui.adsabs.harvard.edu/user/settings/token.

How it works

1. Scans .tex files for \cite{...}, \citep{...}, \citet{...}, and related commands
2. Filters for keys containing : (INSPIRE/ADS format)
3. Fetches BibTeX from the preferred source, with automatic fallback
4. Replaces citation keys to match those used in your .tex files
5. Truncates long author lists
6. Skips keys already present in the output file (use --fresh to override)