A minimal integration POC needs separate field contracts for API acceptance

A minimal integration POC needs separate field contracts for API acceptance and for the claim being tested. A verification-link demo can work with contact information; testing verification against a booked assignment additionally needs a stable external load identity and authoritative expected identifiers. Fields that are optional in a generic schema can be required for a specific POC claim. Conversely, provider adapters may hydrate information that a generic push endpoint requires the caller to supply.

Method: trace validation and normalization in the current code, distinguish provider intake from manual entry, and measure field presence on one latest load-context record per load. Report the cohort boundaries and distinguish current enriched values from creation-time values. Check value shapes as well as presence: an appointment stored as HH:mm does not establish an absolute instant without date and timezone. Treat downstream result correlation, assignment changes and replay behavior as separate acceptance checks.

Limits: field presence does not prove accuracy, provider acceptance does not prove customer adoption, and existing adapter-specific behavior is not a universal public API guarantee.

Applies when: defining a minimal integration POC from an existing multi-provider product. Keywords: TMS integration POC required optional fields assignment identity pickup timezone