analytics: per-bidder EID delivery and troubleshooting fields in auction_processed

[MO-Thibault]

Summary

Adds the fields we kept missing during enrichment and uplift investigations to the V1 analytics add-on (lib/addons/prototypes/analytics.js), which feeds bid_analytics. Each one maps to a case that needed a browser harness or a partner conversation because the table could not answer it.

Per-bidder EID delivery, with no payload growth in the normal case. Today each bidder request's optableSources is computed and then collapsed into one auction-level union, so we cannot tell whether a given bidder received our IDs (ddm: whether msft got any after the appnexus rename). Each bidder request now carries om, a bitmask over the auction-level optableSources (bit i = optableSources[i]). It is omitted when the bidder received every source, which is the common case, so most payloads do not change. Absent means all sources; 0 means none.

New fields

Field	Level	Size	Meaning
bidderRequests[].om	bidder	0 bytes usually, ~7 when present	Sources this bidder received, as a bitmask over optableSources
bidderRequests[].bids[].src	bid	only on s2s bids	"s2s" for Prebid Server responses
unmatchedBids	auction	only when > 0	Received bids that matched no bidder request
slotSeq	auction	~10 bytes	Earlier auctions of this ad unit on this page view (0 = first, >0 = refresh or re-auction)
t0	auction	~10 bytes	ms from page start to auction start
consent	auction	~12 bytes	Bitmask: 1 GDPR applies, 2 GPC, 4 US privacy opt-out, 8 GPP present, 16 TCF blocked storage
cacheAge	auction	~15 bytes	Seconds since the targeting cache was written; -1 when none
idsMs	auction	only when written this page	ms from page start to our IDs landing (compare with t0)
page	first auction of a page only	~60 bytes once	{ rtdOptable, rtdDelay, udDelay }

Documented in lib/addons/prototypes/README.md.

Prebid Server responses

On ddm, prebidServer requests show about 6.7M per day with 0 priced bids recorded. The likely cause is that s2s bid responses carry a requestId that matches no client bidId, so trackAuctionEnd drops them. Received bids that do not match now fall back to the same bidder code and ad unit (first bid still waiting for a response), keep src: "s2s", and anything still unmatched is counted in unmatchedBids. Not yet verified on a live Prebid Server page; unmatchedBids will tell us whether the fallback catches them.

Core change

LocalStorage.setTargeting now also writes <cacheKey>:ts with the write time, and clearTargeting removes it. The cache value itself is unchanged, so wrappers that parse OPTABLE_RESOLVED are unaffected. Control-group clearing that removes OPTABLE_RESOLVED directly leaves the :ts key behind, which is harmless: analytics reports an age only when the cache itself is present.

Not in this PR

• The bid_analytics ETL still needs columns for these fields (separate change in optable-solutions). Until then they are only in the raw payload.
• The V2 add-on (lib/addons/prebid/analytics.ts) is unchanged.
• Bundles need a web-sdk bump to pick this up.

Test plan

• New lib/addons/prototypes/analytics.test.js (14 tests): om omitted and masked, slotSeq counting, t0, each consent bit, the three cache states and custom key, page config on the first auction only, s2s fallback match, unmatched count, client bids unchanged.
• lib/core/storage.test.js: :ts written on setTargeting, removed on clearTargeting.
• Full suite: 30 suites, 500 tests pass. pnpm build-lib passes. pnpm format leaves no diff.
• Load a bundle built from this branch on a test page and check one auction_processed payload.
• On a Prebid Server tenant (ddm), confirm s2s bids now carry CPMs and check unmatchedBids.

🤖 Generated with Claude Code

[jplaroche]

Should we add this to V2 (prebid/analytics.ts) too ?