Synthetic example · field rename

// Agent sends
const request = {
  source: "card_42",
  amount: 2000,
};

# Agent sends
request = {
    "source": "card_42",
    "amount": 2000,
}

// Vendor now expects
const expectedRequest = {
  payment_method: "card_42",
  amount: 2000,
};

# Vendor now expects
expected_request = {
    "payment_method": "card_42",
    "amount": 2000,
}

A selective repair changes only the drifted field, when evidence and policy allow. The amount stays untouched.

A repair changes the payload. Its audit artifact must say so.

Synthetic example · unit change

// Previously: total in cents
const previousResponse = { total: 2000 };

// Now: total in dollars
const response = { total: 20 };

# Previously: total in cents
previous_response = {"total": 2000}

# Now: total in dollars
response = {"total": 20}

The shape still fits. The meaning changed. Explicit statistical windows and invariants can supply evidence; a single response cannot establish a unit change.

Reads fail open. In repair mode, detected semantic write drift without a verified repair fails closed.