Skip to content
Switch branches/tags

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time

Flatpak External Data Checker

Tests Coverage Status Total alerts Language grade: Python CodeFactor

This is a tool for checking for outdated or broken links of external data in Flatpak manifests.


Flatpak apps are built using external data (git checkouts, tarballs, simple files, etc.). A very specific case of this is the use of extra data, which works as a way to download third party binaries at installation time.

Of course, the links pointing to external data can become obsolete, so it is very important to account for and correct such issues. This is especially critical for the extra data, in which a broken link impedes the installation of the application.

This project offers ways to easily check or monitor the state of such links, as well as the suggestion of new versions.

It works by extracting all the external data of a Flatpak manifest and giving it to a collection of checkers, which will set up the right state and, possibly, new versions of each external data.


The simplest use of this tool is by calling:

flatpak-external-data-checker MANIFEST_FILE

it should display messages about any broken or outdated external data.


This tool itself is available in flatpak format from Flathub. Install with

flatpak install --from

And run with

flatpak run org.flathub.flatpak-external-data-checker MANIFEST_FILE

Running in a container

flatpak-external-data-checker is also avaiable as an OCI image from GitHub Container Registry.

You can use the helper script to set up needed CLI options for you and run the image using podman:

~/src/endlessm/flatpak-external-data-checker/ \
    [ARGS …] \

Automatically submitting PRs

When run with the --update flag, this tool can commit any necessary changes to Git and open a GitHub pull request. In order to do this, it requires a GitHub access token, specified in the GITHUB_TOKEN environment variable.

Automatically merging PRs

The tool will also automatically merge previously opened pull request for unavailable (BROKEN) sources if the change has successfully passed CI checks and the token has sufficient privileges.

Automatically merging all submitted PRs, not just unavailable sources, from the tool can be forcefully enabled by setting automerge-flathubbot-prs to true in flathub.json, or it can be completely disabled by setting automerge-flathubbot-prs to false.

Changes to Flatpak manifests

For simple checks to see if a URL is broken, no changes are needed. However, you can add additional metadata to the manifest to allow the checker to discover new versions.

Some of the following checkers are able to determine upstream version number, and automatically add it to releases list in metainfo. To specify which source is the app upstream source, set property is-main-source to true in the checker metadata for that source.

URL checker

If the upstream vendor has an URL that redirects to the latest version of the application, you can add something like the following to check and update the URL for the latest version:

"x-checker-data": {
    "type": "rotating-url",
    "url": "",
    "pattern": "[0-9.]+).tar.gz"

The version number for the latest version can be detected in two ways:

  • If the filename ends with .AppImage, the version number is extracted from the AppImage. (It is run in a bwrap sandbox.)
  • Otherwise, if "pattern" is specified in "x-checker-data", the given regular expression is matched against the full URL for the latest version, and the first match group is taken to be the version. (This follows the convention used by debian/watch files.)

HTML checker

Both the version number and the download URL will be gathered from a static HTML page which contains this information:

"x-checker-data": {
    "type": "html",
    "url": "",
    "version-pattern": "The latest version is ([\\d\\.-]+)",
    "url-pattern": "([\\d\\.-]+)/foo.tar.gz)"

If the HTML page contains multiple versions with download links, set single pattern containing two nested match groups for both url and version:

"x-checker-data": {
    "type": "html",
    "url": "",
    "pattern": "<link>([\\d\\.]+\\d).tar.gz)/download</link>"

To disable sorting and get first matched version/url, set sort-matches to false.

URL templates

The HTML checker also supports building the download URL using the retrieved version string, its components according to the Python LooseVersion class and semantic versioning fields:

"x-checker-data": {
    "type": "html",
    "url": "",
    "version-pattern": "The latest version is ([\\d\\.-]*)",
    "url-template": "$version/v$version.tar.gz"
"x-checker-data": {
    "type": "html",
    "url": "",
    "version-pattern": "The latest version is ([\\d\\.-]*)",
    "url-template": "$major.$minor/v$version.tar.gz"

If the placeholder is immediately followed by an underscore, you need to add braces:

"x-checker-data": {
    "type": "html",
    "url": "",
    "version-pattern": "The latest version is ([\\d\\.-]*)",
    "url-template": "$version0.$version1/v${version0}_${version1}_version2.tar.gz"

Git checker

To check for latest git tag in corresponding git source repo, add checker metadata with type git and set tag-pattern to a regular expression with exactly one match group (the pattern will be used to extract version from tag):

"x-checker-data": {
    "type": "git",
    "tag-pattern": "^v([\\d.]+)$"

By default tags are sorted based on version number extracted from tag. To disable sorting and keep order from git ls-remote, set sort-tags to false.

If the project follows semver specification, you can set version-scheme property to semantic in order to use semantic version scheme for sorting. In this case, make sure that tag-pattern extracts only valid semver strings.

JSON checker

The JSON checker allows using jq to query JSON data with arbitrary schema to get version and download url.

To use the JSONChecker, specify JSON data URL, version query and url query (you can use $version variable got from the version query in url query):

    "type": "json",
    "url": "",
    "version-query": ".tag_name | sub(\"^jq-\"; \"\")",
    "url-query": ".assets[] | select(.name==\"jq-\" + $version + \".tar.gz\") | .browser_download_url"

for git type sources, specify tag query and, optionaly, commit and version queries:

    "type": "json",
    "url": "",
    "tag-query": ".tag_name",
    "version-query": "$tag | sub(\"^jq-\"; \"\")",
    "timestamp-query": ".published_at"

timestamp-query is optional, but if provided - must return a string with timestamp in ISO format.

See the jq manual for complete information about writing queries.

Debian repo checker

For the DebianRepoChecker, which deals only with deb packages, it can read the following metadata (add it to manifest element it refers to, e.g. where "type": "extra-data" is declared):

"x-checker-data": {
    "type": "debian-repo",
    "package-name": "YOUR_PACKAGE_NAME",
    "dist": "DEBIAN_DIST",
    "component": "DEBIAN_COMPONENT"

Anitya (release-monitoring) checker

Anitya is an upstream release monitoring project by Fedora. It supports multiple backends for retrieving version information from different services, including GitHub, GitLab, Sourceforge, etc. To use the AnityaChecker, specify numeric project ID on and add a template for source download URL. Template syntax is the same as for the HTMLChecker:

"x-checker-data": {
    "type": "anitya",
    "project-id": 6377,
    "stable-only": false,
    "url-template": "$version/flatpak-$version.tar.xz"

Set stable-only to true to retrieve latest stable version (as recognized by Anitya).

For git type sources, instead of url-template, set tag-template to derive git tag from version.

GNOME checker

Check for latest source tarball for a GNOME project.

"x-checker-data": {
    "type": "gnome",
    "name": "pygobject",
    "versions": {
        "<": "3.38.0"
    "stable-only": true

Set stable-only to false to check for pre-releases, too.

You can also set version constraints in versions property (optional).
It should contain key-value pairs where key is the comparison operator (one of <, >, <=, >=, ==, !=), and the value is the version to compare with. So, {"<": "3.38.0", "!=": "3.37.1"} means "any version less than 3.38.0 except 3.37.1". All constraints must match simultaneously, i.e. if one doesn't match - version is rejected.

PyPI checker

Check for Python package updates on PyPI.

"x-checker-data": {
    "type": "pypi",
    "name": "Pillow"

By default it will check for source package (sdist package type). To check for binary package instead, set packagetype to bdist_wheel (only noarch wheels are supported currently).

JetBrains checker

Special checker that will check for available updates for JetBrains products:

"x-checker-data": {
    "type": "jetbrains",
    "code": "PRODUCT-CODE",
    "release-type": "release or eap (defaults to release)"

Snapcraft checker

Special checker that will check for available updates for Snapcraft packages:

"x-checker-data": {
    "type": "snapcraft",
    "name": "PACKAGE-NAME",
    "channel": "stable, beta, or any other tag the project uses"

Rust checker

Special checker that will check for available updates for Rust:

"x-checker-data": {
    "type": "rust",
    "package": "package name, for example: rust",
    "channel": "nightly, stable or beta",
    "target": "target triple, for example: x86_64-unknown-linux-gnu"

Chromium checker

Special checker that will check for available updates to the Chromium tarballs, as well as the toolchain binaries or sources used to build it.

"x-checker-data": {
    "type": "chromium",
    "component": "chromium, llvm-prebuilt, or llvm-git; defaults to chromium"

The following components are supported:

  • chromium: updates the Chromium tarball itself, used on URL-based sources (e.g. type: archive).
  • llvm-prebuilt: updates a tarball pointing to the official LLVM prebuilt toolchain archive matching the latest Chromium version. Used on URL-based sources.
  • llvm-git: updates a type: git source for its commit to point to the LLVM sources for the toolchain used by the latest Chromium version.

License and Copyright

License: GPLv2

Copyright © 2018–2019 Endless Mobile, Inc.


A tool for checking if the external data used in Flatpak manifests is still up to date