KCC 08.5

Capability Lifecycle Economics

Capabilities are not just born and promoted — they live, branch, contend, age, and die; this section covers the lifecycle the maturity ladder alone does not answer.

MaturityLifecycle eventsDeprecationForksMaintenance burden
Created 2026-06-08 · v0.4.0

Why This Section Exists

Section 8 specifies how capabilities are promoted. The full lifecycle is more than that. Capabilities are also forked, merged, fragmented, contested, abandoned, and retired. They consume maintenance burden that grows or shrinks with usage. This section covers the lifecycle questions the maturity ladder alone does not answer — and it is the area of v0.4 with the least production evidence.

Lifecycle Events Beyond Promotion

EventDescription
CreationNew L1 capability registered
PromotionL1 → L2, L2 → L3 (Section 8)
ForkDivergent variant created, typically by a cell with specialized needs
MergeTwo related capabilities unified into one
FragmentationCapability split into multiple smaller capabilities
Ownership Transfer / DisputeMaintainer changes, or parties contest direction
Demotion / Deprecation / Retirement / ArchiveMovement down, marked for removal, removed, or removed-but-retained-for-audit

When Does a Capability Die?

A capability should be retired when any of the following is true:

  • Superseded — another capability does it better and cells are migrating naturally
  • Adoption collapse — L1 unused 6+ months; L2 fewer than 2 cells 6+ months; L3 below 30% with declining trend
  • Maintenance burden exceeds value — the maintainer spends more keeping it current than it returns
  • The underlying problem has changed — absorbed into the kernel, or this is now the wrong solution
  • The capability is causing harm — consistent workslop, hidden cost, repeated trace anomalies

Deprecation Mechanics

LevelMinimum Migration WindowRationale
L1None requiredNo commitments made
L290 daysCells need time to plan and migrate
L3180 daysWide adoption means many cells migrate
L3 + critical12+ monthsSome L3 deprecations are major organizational events

During the window the deprecated capability keeps working, the catalog marks it with the sunset date, and the Inspector Pipeline tracks remaining adopters. The default for a missed sunset should be to force the migration rather than extend indefinitely — indefinite-extension capabilities become zombies.

Forks, Merges, Fragmentation

The worst fork is the silent fork: a cell modifies a copy without registering it, so cells reading the catalog assume they use the canonical version when each has its own diverged copy. The kernel should detect this through telemetry — agents declaring spec-writer@2.1 but behaving differently are flagged. Merges are right when two capabilities address substantially the same problem (>70% overlap); fragmentation is right when one capability has accreted unrelated functionality. The general principle: let the shape emerge from usage; don't impose it ahead of usage.

Ownership Disputes

A capability's direction is not always agreed. Kernel maintainers mediate maintainer disagreements; conflicting cell directions are resolved by choosing one, fragmenting, or adding an optional surface. The healthy norm: a capability without a willing maintainer must be deprecated, regardless of adoption.

Maintenance Burden Economics

LevelMaintainer Time (est.)Why
L10-5% of an engineerBest-effort; no commitments
L25-15% of an engineerIssue response, version maintenance, migration support
L315-30% of an engineerMulti-cell support, deeper backward compatibility, longer windows

Decreasing burden is the healthy long-term pattern. Increasing burden — adoption growing faster than economy of scale, or the kernel evolving faster than the capability keeps up — is a signal: invest more, fragment, or retire.

Don't let capabilities zombie. Don't fork silently. Don't merge prematurely. When the lifecycle event happens, declare it explicitly and follow the structural process.