Saves draft suggestions only. Does not run credit, submit applications, accept consent/signatures, or send messages. Unknown fields are rejected at every level. Body limit: 64 KB. Saved/submitted records and already-open forms are not overwritten. SSN, income/employment, banking, consent/signature, selected-offer and equipment-specification fields are rejected.

Idempotency keys are scoped to property + HTTP method. Equivalent retries return the original success without applying again. Keys are retained at least 24 hours, normally 24–48 hours; retries do not extend retention. After expiration, key reuse executes again.

Requires an existing unarchived Project with a draft, currently owned by this property. Never creates or moves a Project. Different-key patches to different fields survive; same-field changes use the last committed write. Submitted applicant and application records remain unchanged.