create_media_buy / get_media_buys response schemas: currency and total_budget required asymmetry

[fgranata]

Summary

create-media-buy-response.json and get-media-buys-response.json have inconsistent required arrays for what should be the same media buy object shape. A seller correctly implementing create_media_buy per its schema will Zod-fail get_media_buys validation on every poll step — and vice versa.

Schema diff (3.0.11)

Field	create-media-buy-response.json §CreateMediaBuySuccess	get-media-buys-response.json §media_buys[i]
required	["media_buy_id", "packages"]	["media_buy_id", "status", "currency", "total_budget", "packages"]
currency	not listed in properties	required
total_budget	not listed in properties	required
created_at / updated_at	not listed in properties	listed (optional)

Impact

A seller implementing deal_to_media_buy (create) and deal_to_media_buy_summary (list) using a single shared mapper will either:

• Strip currency + total_budget correctly per the create schema → silently Zod-fail every get_media_buys poll step downstream
• Include currency + total_budget per the list schema → emit fields not in the create schema

Identified during Wave 23.20.7 by a seller whose shared mapper applied the create schema uniformly to both endpoints. The get_media_buys cascade caused 63/128 storyboard score across multiple runs with no server-side errors — all failures were silent Zod rejections at the runner layer.

Expected behavior

currency and total_budget should be present in both schemas with consistent required status. Both responses represent the same media buy entity — buyers expect the same fields regardless of which operation returned it.

Suggested fix

Either:

1. Add currency and total_budget to create-media-buy-response.json properties + required array (preferred — buyers need these fields at creation time too)
2. Or document explicitly that the two response shapes are intentionally different and why — so sellers know to use separate mappers

Labels

bug, schema, media-buy

[bokelley]

Triage

Classification: Bug
Bucket(s): spec / protocol, schema, media-buy
Status: drafting-pr
Milestone: 3.1.0 (MINOR — additive optional fields on stable surface)

What the experts said:

• ad-tech-protocol-expert: Gap is genuine — currency and total_budget absent from CreateMediaBuySuccess/UpdateMediaBuySuccess properties forces shared-mapper sellers to omit them, causing the silent Zod failures on get_media_buys poll steps you observed. Adding as optional is non-breaking; the required asymmetry is intentional for status but unintentional for these two fields. Bump: MINOR.
• adtech-product-expert: Buyers need currency/total_budget at creation time, especially in proposal mode where both values are deterministic. Optional fix is directionally correct but undershoots — argues they should be required in CreateMediaBuySuccess (particularly for proposal mode). That is breaking (MAJOR) and left for @bokelley.

My take: Opening a draft PR that adds both fields as optional to CreateMediaBuySuccess and UpdateMediaBuySuccess — non-breaking, targets 3.1.0. The required-in-create question is a policy call: if the WG wants to require them in proposal mode, that ships as a MAJOR (or MINOR if experimental-surface rules apply). Surfacing for @bokelley in the PR body.

Drafted in #4417.

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Triaged by Claude Code. Session: https://claude.ai/code/session_01QH73KwxYwPBV4uF551zAE1

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