Conda License Lint: Anaconda defaults channel

6 paid Anaconda channel lines sat in one churn-model environment.yml we linted — the kind of file a Python data team at a company with 200 or more people copies from repo to repo.

Anaconda's Terms of Service require a paid licence for organisations of 200 or more people that use the defaults channel. The anaconda channel on anaconda.org is a mirror of defaults and carries the same terms. conda-forge, bioconda and other community channels stay free. Anaconda lists its Business plan at $50 per user per month.

The file looked ordinary:

channels:
  - defaults
  - anaconda
  - https://repo.anaconda.com/pkgs/r
  - pkgs/msys2
dependencies:
  - python=3.11
  - pkgs/main::numpy=1.26
  - defaults::pandas

Conda License Lint reports 6 findings on it, one per line that reaches Anaconda's repository:

• L3 defaults-channel: - defaults is short-hand for repo.anaconda.com/pkgs/main and pkgs/r, plus pkgs/msys2 on Windows.
• L4 anaconda-channel: the anaconda.org mirror of defaults.
• L5 repo-anaconda-url: a direct repo.anaconda.com URL.
• L6 pkgs-channel-name: pkgs/msys2 resolves to the same repository.
• L9 and L10 channel-pinned-dependency: pkgs/main::numpy=1.26 and defaults::pandas.

The two pins are the ones a quick search misses. A channel::package prefix tells conda where to fetch that one package, so it goes to Anaconda even after someone cleans up the channels list.

The fixed file lists - conda-forge and - nodefaults, pins conda-forge::pandas, and the linter reports 0 findings on it.

Why nodefaults matters: conda env create adds the channels from your conda configuration after the ones in the file. Miniconda and Anaconda installers put defaults there. So a file that lists only conda-forge still reaches defaults unless its list ends with - nodefaults. The linter flags that case as a warning, implicit-defaults, and points at the channels line.

The machine configuration is the other half. A .condarc with default_channels: pointing at repo.anaconda.com decides what the word defaults means on that machine. Each such entry is a condarc-default-channels finding. On the three-line Miniconda-style .condarc we tested, the linter reports 3 findings: the defaults channel and two default_channels URLs.

There is a CI angle too. Since Anaconda Distribution 2025.06-0 the installers ship the conda-anaconda-tos plugin, and the channels repo.anaconda.com/pkgs/main, pkgs/r and pkgs/msys2 need conda tos accept, or the CONDA_PLUGINS_AUTO_ACCEPT_TOS variable, before a non-interactive build uses them. A build that suddenly stops at a Terms of Service prompt is a sign the pipeline is still on defaults.

The 8 rules in the extension:

1. defaults-channel
2. anaconda-channel
3. repo-anaconda-url
4. pkgs-channel-name
5. channel-pinned-dependency
6. condarc-default-channels
7. implicit-defaults (warning)
8. mixed-with-conda-forge (warning)

Findings land in the VS Code Problems panel with the line number, the reason and the conda-forge replacement. The files it watches are environment*.yml, environment*.yaml, .condarc and condarc.

The free version checks the file you have open with no key, and the web page runs the same engine: paste a file, get the same findings. The full version scans every environment file and .condarc in a workspace in one run and exports a single licence-audit report you can hand to procurement or security.

It is not legal advice. Whether your organisation holds an Anaconda licence is between you and Anaconda; the linter shows which lines reach Anaconda's repository.