An invocation materializes one program entry, target, input set, repository, and run lineage. Every required reachable operator parameter must have exactly one admissible producer: entry input, trusted resolver, durable state, receipt, foreground-work output, or bounded host input.
Foreground work produces candidate artifacts under a declared input, instruction, and output contract. A typed suspension records missing actor-owned input, authority, or work without guessing.
Invocation completeness is checked before an executable artifact is accepted. At runtime, missing actor-owned values suspend the same run. Answers are evidence for parameter materialization, not authority to perform an effect.
- Each required parameter has exactly one compatible producer.
- Trusted resolvers are immutable references and do not grant authority.
- Foreground-work completion does not independently advance Flow state.
- Same-transition parameters consume the candidate result being admitted.
- Later transitions and Work contracts consume only the applicable committed result.
- A cross-transition Work producer remains source-admissible at its own target so current-program evidence can be refreshed.
- A later result commits the exact producer receipt, result, contract, output, and byte identities.
- Requests and answers are correlated to the exact run and generation.
- Restart and resume preserve the same run and request lineage.
Compilation proves producer completeness for every reachable transition. Runtime creates immutable input or work requests when materialization cannot continue. A correlated answer or work result resumes the same run; rejected values are superseded with a linked generation instead of being overwritten.