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# Supply path (SPO) feed

> Supply path optimization (SPO) feed reference. Definitions, file name, schema, cadence and how to block flagged supply chain nodes pre-bid.

The supply path optimization (SPO) feed lists supply chain nodes that Pixalate associates with higher invalid traffic (IVT). Use it to reduce the number of supply paths you buy through and to block specific entities in the supply chain before the impression, instead of blocking a whole seller, publisher, app, site or user.

## Definitions

| Term               | Meaning                                                                                                                                                                                                 |
| ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Node               | In a complete supply chain, a node is one advertising system and seller ID involved in the transaction.                                                                                                 |
| Advertising system | The domain name of the SSP, exchange, header wrapper or other system that bidders connect to. This may be the system's operational domain if it differs from the parent company's domain.               |
| Seller ID          | The identifier of the seller or reseller account within the advertising system. It's the same value used in transactions (for example OpenRTB bid requests) in the field the SSP or exchange specifies. |

A node is the combination of advertising system and seller ID (`adSystem:sellerId`). A listed node flags that specific seller account on that system, wherever it appears in a supply path. It isn't a block of the seller everywhere.

## File format and cadence

|                        |                         |
| ---------------------- | ----------------------- |
| Format                 | CSV                     |
| File name              | `SpoBlocklist_YYYYMMDD` |
| Update frequency       | Daily                   |
| Estimated availability | 8:00 AM UTC             |

For access, delivery and polling, see [Delivery and integration](/data-feeds/delivery).

## Schema

| Column        | Description                                                                                                                 |
| ------------- | --------------------------------------------------------------------------------------------------------------------------- |
| `adSystem`    | The advertising system domain of the node.                                                                                  |
| `SellerId`    | The seller ID of the node within that advertising system. Note the capital `S` in the column name.                          |
| `riskType`    | The risk type associated with the node. Contact [support@pixalate.com](mailto:support@pixalate.com) for the list of values. |
| `probability` | The probability associated with the node. Use it to decide how much of the list to apply.                                   |

## Apply it pre-bid

* **Block bid requests whose supply chain object contains a flagged node.** Compare each `adSystem` + `SellerId` pair in the request's supply chain with the feed, regardless of the node's position in the chain.
* **Block paths, not whole sellers.** Because the feed works at node level, you can remove a risky path while still buying from the same seller, publisher, app or site through other paths.
* **Tune with probability.** Apply more or less of the list by filtering on `probability`.
* **Focus on specific IVT.** Use `riskType` to target supply paths associated with the IVT types you care about most.

## Related feeds

* [MFA data feeds](/data-feeds/mfa): made-for-advertising websites and apps.
* [High Risk Domains](/data-feeds/high-risk-domains): website block lists.
* [IP block lists](/data-feeds/ip-block-lists): block invalid traffic by IP address.

Questions? Email [support@pixalate.com](mailto:support@pixalate.com).