Stack Ownership Boundary
- Frontier models
- Inference capacity
- Routing between providers
- Harness integration
- Context packaging
- Tool descriptions
- Identity and policy
- Domain action contracts
- Episode catalog and accepted outcomes
For a technology leader the question is not which logo to pick but where to draw the ownership boundary. Two axes give the answer: how fast a component changes and how unique it is to your environment.
Rent frontier models — they change quickly and are rarely enterprise-specific, so routing between providers makes sense. Adapt harness integration, context packaging and tool descriptions: they also change quickly but must fit your environment. Own identity, policy, domain action contracts, the episode catalog and accepted outcomes — these define the right to act and the very meaning of success.
An owned harness must be earned with five yes answers: a unique action environment, sovereignty or extreme latency needs, sufficient volume, mature evals, and agent capability as part of the external product. The fewer the yes answers, the more expensive the wish to control everything becomes.
Score each stack component on two axes: how fast it changes and how unique it is to your environment.
Sort the components into the three zones and name an owner for each zone.
Before building your own harness, test five conditions: a strong team alone is not a business case.