The Seam

Each harness pattern is written behind an interface — a seam — with an offline local implementation swappable for an Azure-backed one, turning a bare model call into production agent infrastructure

The Seam Each harness pattern is written behind an interface — a seam — with an offline local implementation swappable for an Azure-backed one, turning a bare model call into production agent infrastructure Swappable behind the seam Bare Call · model only · Architecture component Bare Call model only Harness · production agent · Architecture component · wraps Harness production agent wraps Interface Seam · one contract · Architecture component · swappable Interface Seam one contract swappable Local Impl · offline / CI · Swappable behind the seam · deterministic Local Impl offline / CI deterministic Azure Impl · production · Swappable behind the seam · managed Azure Impl production managed LLM · Foundry model · Architecture component LLM Foundry model wrap depends on CI production calls Legend External Backend Security Cloud

One Contract

  • • Every pattern hides behind an interface
  • • The seam is the single swap point
  • • Callers depend on the contract, not the backend

Two Implementations

  • • Local impl is deterministic and offline for CI
  • • Azure impl is the managed production backend
  • • Swapping one for the other changes no caller

Seven Seams

  • • Model, memory, tools, and identity behind seams
  • • Policy, telemetry, and checkpoint behind seams
  • • A bare model call becomes production infrastructure

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