A shared library README should answer five things in under fifteen lines: which team owns it, how to reach them, which versions receive security fixes, how to report a vulnerability, and when it was last reviewed. Engineers read the README first, so that is where ownership has to live.
Why the README
Catalog entries and org charts drift. The README sits next to the code and shows up in every pull request and package page. A consumer who finds a bug at 4 pm will not open a wiki, but they will scroll the README.
Keep the section short. It is a pointer, not a policy manual.
The five fields
| Field | Example wording | Why it matters |
|---|---|---|
| Owning team | Team name and channel | One place to ask |
| Maintainers | Two or more handles | Survives one person leaving |
| Supported versions | Latest minor of the current major, plus the previous major for security fixes | Consumers know whether to upgrade or wait |
| Security reports | Private route, not a public issue | Avoids disclosing before a fix |
| Review date | A date, reviewed at least twice a year | Stale entries are visible |
A template you can paste
Use a heading such as "Ownership and support" and fill in these lines:
- Owner: the team name, with its channel or queue.
- Maintainers: two or more people from that team.
- Supported versions: state the rule in one sentence.
- Report a security problem: the private route and the expected first response time.
- Breaking changes: you follow semantic versioning and announce majors at least a stated period ahead.
- Last reviewed: the date.
Do not promise what the team cannot deliver. A response time you miss is worse than none.
Tie it to tooling
A README is only text. Pair it with machine readable ownership so scanners and ticket routers can use it. A CODEOWNERS file asks the right reviewers on every change, and GitHub allows required review from code owners through branch protection. A catalog entry with an owner field lets a vulnerability finding go to the owning team automatically.
Semantic versioning as a promise
If you state that you follow semantic versioning, mean it. The specification says that once a version is released, its contents must not be modified, and any change ships as a new version. Patch versions are for backward compatible bug fixes, and minor versions must be incremented when public API functionality is marked deprecated. Consumers plan their upgrades on those rules.
Review rhythm
Put a calendar reminder on the owning team to re read this section every six months and after every team change. Add a check in CI that fails if the review date is older than a year, if you want an enforced version.
Safeguard can help with the inventory side: its SBOM and dependency scanning shows which services pull in a given internal library, and you can run a free scan at gold.safeguard.sh/scan.
Quick check
Should the README list every consumer?
No. Consumer lists go stale. Generate them from your dependency graph or SBOMs instead.
Where do security reports go?
To a private route owned by the library team, such as a security contact address or private advisory feature, rather than a public issue.
Sources
- GitHub: About code owners
- Semantic Versioning 2.0.0
- Backstage: Descriptor format of catalog entities
Last reviewed: 19 October 2026.
