[Bug Fix] Insticator Bid Adaptor: Move DSP seat from TypedBid.Seat to Meta.Seat to prevent bid rejection

[shubhamc-ins]

The Seat field on TypedBid was being set to raw DSP seat strings (e.g. pubmatic_54229, criteo_46) which triggered the alternateBidderCodes validation in the PBS exchange, silently dropping 100% of bids for publishers without explicit config.

• Remove Seat from TypedBid to avoid alternateBidderCodes rejection
• Store DSP seat in ExtBidPrebidMeta.Seat for reporting (same approach as Rubicon adapter)
• Update test cases to reflect removed TypedBid.Seat

[github-actions]

Code coverage summary

Note:

• Prebid team doesn't anticipate tests covering code paths that might result in marshal and unmarshal errors
• Coverage summary encompasses all commits leading up to the latest one, d1c0e13

insticator

Refer here for heat map coverage report

github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:62:	Builder			80.0%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:75:	parseExtraInfo		66.7%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:89:	buildEndpointURL	90.9%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:111:	getMediaTypeForBid	100.0%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:122:	MakeRequests		96.9%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:179:	makeRequest		94.1%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:218:	MakeBids		100.0%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:253:	getBidMeta		100.0%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:272:	getBidVideo		100.0%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:288:	makeImps		86.7%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:332:	makeReqExt		100.0%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:354:	resolveBidFloor		100.0%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:363:	validateVideoParams	100.0%
github.com/prebid/prebid-server/v4/adapters/insticator/insticator.go:374:	populatePublisherId	100.0%
total:										(statements)		94.8%

[shubhamc-ins]

Hi @bsardo,

We found a bug introduced in #4668 that silently drops 100% of bids from our adaptor. Here's a quick summary:

The problem:

• TypedBid.Seat is set to raw DSP seat strings (e.g. "pubmatic_54229", "criteo_46")
• These aren't registered Prebid bidder codes
• PBS exchange calls alternateBidderCodes.IsValidBidderCode("insticator", "pubmatic_54229") → false
• Every bid gets dropped unless the publisher explicitly configures alternateBidderCodes (disabled by default)

The fix (this PR): This PR fixes that bug

• Removes Seat from TypedBid to avoid the rejection
• Stores DSP seat in ExtBidPrebidMeta.Seat, for optional reporting purposes for pubs.

Request:

We'd really appreciate it if this fix could be included in the next immediate release of PBS-Go, as it's currently blocking all bids for publishers running the latest version.

Additionally, since prebid-server Java hasn't been updated with the changes from #4668 yet — would it be possible to land both the original feature and this fix together in a single Java release, so the bug never gets introduced on that side?

Please let me know if anything else is needed from my side. Thanks a lot!

[shubhamc-ins]

Hey, @bsardo apologies for tagging you again.

Did anyone get a chance and time to review this?
I appreciate if this can be checked and released with upcoming release as this would affect our clients.