Opens with a rule about its own maintenance, then covers commands, a task-to-location table, cross-tool development, and testing conventions. Subsystem detail is delegated to per-package files.
Quoted passages are verbatim. Open one to see it in the source.
01 / Pointing at the source of truth
A stated policy against copying
The second sentence of the file rules out copying details into it, naming versions, rule lists and counts as the things that go stale. Later sections apply it: the root package file is named as authoritative for scripts, and a validation command replaces a duplicated list of enforced lint rules.
Source excerpt starting at line 4.
4monorepo. Prefer authoritative configuration and documentation over copying5details into this file: copied versions, rule lists, and counts become stale.
02 / From this file
A table indexed by task, not by directory
Fourteen rows map a thing the agent might be asked to do onto the location that handles it, with a note on each. The first column is the task rather than the path, so the table is read by intent.
03 / From this file
A rule about which layer a feature belongs in
Three tools consume the same development platform, so a feature is stated to be incomplete if it only works through one of them. Implementation goes in the shared layer wherever possible, with the integration layers kept thin, and intentional gaps documented in the pull request.
Source excerpt starting at line 61.
61Workers development platform. A development feature is not complete merely62because it works through one of them.
04 / Nested instruction files
Package files kept current in the same change
Packages carry their own instruction files, and the agent is directed to read the closest applicable one before making changes and to update it in the same change when the change makes it inaccurate. The division of content between the root file and package files is stated.
05 / Hard prohibitions
One security rule with its linter
Shell commands may not be built from interpolated or concatenated untrusted input, and the custom lint rule that enforces it is named.
Put it to work
Borrow this for your repo
01Put the anti-drift rule in the file itself. Naming versions, rule lists and counts as things not to copy is what keeps it from rotting.
02Index your repo map by task rather than by directory. Agents arrive with an intent, not a path.
03If several tools consume one platform, state which layer a feature belongs in and that one consumer is not done.
04Require the package instruction file to be updated in the same change that makes it wrong.
Workers SDK's file tells an agent how the codebase works. It cannot tell it which bug three customers hit this week. Modem keeps that context current and attaches it to the work.
