openrtb.schain.node.hp_unexpected
What it means
A node carries an hp value other than 1. The flag says whether the node participates in the payment flow, and version 1.0 of the SupplyChain object expects every node on the declared path to be marked as participating.
Why it matters
hp is how buyers tell the money path from pass-through intermediaries. A node claiming to be outside the payment flow on a 1.0 chain is either a builder bug or a hop that should not be in this object at all, and either way the chain stops classifying cleanly.
How to fix it
Set hp to 1 on every node you append. If a system genuinely does not touch payment, the question to settle is whether it belongs in the chain, not whether to flag it with hp: 0.
Example that trips it
{ "source": { "schain": { "ver": "1.0", "complete": 1, "nodes": [{ "asi": "exchange.example", "sid": "pub-42", "hp": 0 }] } } }Check your payload
Paste a bid request or response into the tester to see whether this code fires against it, or gate on the id in CI with the CLI: the id is stable, wording is not.
Back to the full diagnostic code reference.