Amazon Firefly rules cover two DV measurement endpoints.

The Amazon Firefly pack applies to vfw.amazon-adsystem.com/dv/event.png and /dv/proxy/sts.png. Its existing measurement contract requires populated vstevt and validates ctx, cmp, plc, and sid when those fields are supplied.

Wrapper telemetry at /dv/vtrk.doubleverify.com/ and other /dv/ paths stays outside this pack. IAS /ias/ requests retain directory attribution and core checks. Proxy verification-error variants retain the existing vstevt requirement pending a separately sourced contract. The Ad Tag loader is vendor/amazon-ads.

What this pack matches

Hosts: vfw.amazon-adsystem.com
Paths: /dv/event.png, /dv/proxy/sts.png
Vendor docs: advertising.amazon.com/resources/ad-policy/approved-3p-ad-servers

Rules

Codes are stable. A finding in CI, MCP, or the playground lands on the same id.

Field	Required	What it checks	Rule ids	Source
`vstevt`	required	It is the Firefly viewability event code on the contracted /dv/event.png and /dv/proxy/sts.png measurement hops. The linked Amazon policy is ecosystem context, not a specification of this query. The existing measurement contract requires a non-empty value; proxy verification-error variants need a separate authoritative contract before that requirement can change. Fix: Export the Firefly VAST again from Amazon DSP so vstevt is present on the /dv/ hop.	`vendor.amazon-vfw.param.vstevt.missing` `vendor.amazon-vfw.param.vstevt.empty`	docs
`ctx`	optional	It is the DoubleVerify context or advertiser key. Google documents it as ctx inside dvparams. Generated /dv/proxy tags carry the same name. Quartile /dv/event.png hops often omit it. Fix: Keep ctx from the generated Firefly /dv/proxy tag, or drop the empty pair.	`vendor.amazon-vfw.param.ctx.empty`	docs
`cmp`	optional	It is the DoubleVerify campaign key. Google documents it as cmp inside dvparams. Generated /dv/proxy tags carry the same name. Fix: Keep cmp from the generated Firefly /dv/proxy tag, or drop the empty pair.	`vendor.amazon-vfw.param.cmp.empty`	docs
`plc`	optional	It is the DoubleVerify placement key. Google documents it as plc inside dvparams. Generated /dv/proxy tags carry the same name. Fix: Keep plc from the generated Firefly /dv/proxy tag, or drop the empty pair.	`vendor.amazon-vfw.param.plc.empty`	docs
`sid`	optional	It is the DoubleVerify site or supply key. Google documents it as sid inside dvparams. Generated /dv/proxy tags carry the same name. Values may be a name rather than digits. Fix: Keep sid from the generated Firefly /dv/proxy tag, or drop the empty pair.	`vendor.amazon-vfw.param.sid.empty`	docs

Validate a payload

pixellint validate url "$ARTIFACT" --rulepack vendor/amazon-vfw

Try this failing payload in the playground. Amazon Firefly DV hop missing vstevt.

https://vfw.amazon-adsystem.com/dv/event.png?dup=CJmCexample

cargo install pixellint · npm install pixellint