Concepts/Definition

Application context: a plausible plan may be impossible to run safely

An agent proposes: read employee records, calculate adjustments, submit the batch, and notify staff. The prose is coherent, but approval is missing, two steps write the same table concurrently, and notification may occur before the transaction succeeds. Discovering those defects step by step exposes them to the real system.

Definition

Plan Compilation turns a model-produced structured plan into an executable graph and checks legality, dependencies, authority, conflicts, economy, and acceptance before execution. A rejected plan returns explicit diagnostics for revision or human review instead of guessing during execution.

Engineering mechanism

The compiler validates step types and argument schemas, makes dependencies explicit, calculates write-conflict domains, checks caller authority and tool versions, and estimates repeated scans, serial-versus-parallel choices, call counts, and budget. Its output pins a plan hash, node contracts, resource keys, and recovery policy. Runtime adaptation is limited to declared dynamic points.

Boundary

Low-risk exploration can plan while observing and may not need full compilation. Cross-system writes, batches, approvals, parallel work, and long-running execution benefit from it. Compilation proves structural executability, not that the model understood the business goal; Context Contracts and external acceptance remain necessary.