By its original 22 October 2026 deadline, the OpenProposal 3.0 public comment period had 52 comments and change requests on the record, filed by 17 GitHub accounts on IAB Tech Lab's public issue tracker. The filings cluster around ten themes, led by inventory and targeting detail, the shape of line items, commercial terms and counter-offers, and how a proposal's lifecycle and assent are recorded. Under IAB Tech Lab's published process, the working group now gives every comment a written disposition, publishes a disposition log and tags a revised draft.

TL;DR. OpenProposal is the core object of AAMP 3.0, IAB Tech Lab's Agentic Advertising Management Protocols, and describes what is being bought and sold in a form a buying agent can read. The draft opened for comment on 22 September 2026, and IAB Tech Lab has extended the deadline from 22 October to 10 November 2026; anyone with a GitHub account could file. Of the 52 filings, 29 were change requests proposing specific wording and 23 were comments, and each will resolve to one of six published dispositions.

Counts come from the issue tracker as read on the closing day, so filings made later that day may be missing.

What is OpenProposal 3.0, and why was it open for comment?

The OpenProposal repository describes the specification as "the core AAMP 3.0 object: the descriptive specification for what is being bought and sold, engineered so a buying agent can parse and evaluate it at machine speed." It sits within AAMP, and each line item lands in an existing IAB Tech Lab execution standard (OpenDirect 2.1, the Deals API or OpenRTB 2.6) according to how it is transacted.

The README is clear that the current text is a draft and not yet a ratified standard. It also states the design claim commenters were asked to test: of 71 fields, only 3 require a round trip with the counterparty, because composition is treated as "constraint satisfaction, not negotiation."

IAB Tech Lab opened the draft to everyone. In the README's words, "Anyone may comment; the working group reviews every comment and decides its disposition." For a plain-English primer on what a proposal contains, see What is OpenProposal?

Who filed comments on the OpenProposal draft?

Seventeen GitHub accounts filed issues, including a maintainer account that posted the seven open questions and a summary of feedback from IAB Tech Lab's Agentic Bootcamp on 24 September 2026. The comment form asks each filer to declare a role. Declared roles include publishers and sellers, supply-side platforms, a demand-side platform, buyers, a measurement and verification vendor, a content classification vendor, an ad tech provider, an IAB Tech Lab member, working group participants and individuals commenting without an organisational position.

Declared roles are self-reported rather than verified company affiliations, so most filings are best read by role. The issue tracker remains the authoritative record of who filed what.

One company that filed under its own name is Alkimi, an enterprise platform for agentic advertising, through the VJAlkimi account. It filed four change requests and five comments, covering buyer selections (#22), a field for the buyer's counter-offer and how the agreed rate is derived (#30), naming the line-item container (#31) and validating creative assets against the selected formats (#32). Its comments covered undefined keys (#33), the brief a custom proposal must reference (#34), who computes derived fields (#35), expanding workstream abbreviations (#36) and the worked examples (#37).

What themes did the OpenProposal comments raise?

Grouping the 52 filings by main subject gives ten themes. The grouping is editorial: many issues cite several sections, and each is counted once under its main subject.

Inventory, channels and targeting (12). App identity, content language, linear TV scope, OOH as a channel distinct from DOOH, inventory composition, transport and placement environments, brand suitability disclosure, content categories, buyer block lists and typed geo codes aligned with OpenRTB 2.6.
Object shape and line items (8). Naming the line-item container, line-item dependencies and bonus lines, proposal templates, a static manifest, cross-publisher composition, identifying the seller by domain, undefined keys, and the brief a custom proposal references.
Commercial terms and counter-offers (7). A field for the buyer's counter, how the agreed rate is derived, per-geo options, guidance alongside the floor, the floor as an offer floor rather than an auction floor, versioned commitments, and how holds and seller acceptance are recorded.
Lifecycle, versioning and assent (7). Which document governs the proposal, who moves each status, freezing a version's offered terms, recording seller revisions in the history, defining a record digest and assent, and stating that the lifecycle ends at agreement.
Audience, measurement and verification (5). A unit for addressable scale, binding each committed metric to the measurement source that settles it, audience measurement methodology, guaranteed audience delivery and a third-party verification field.
Identity, eligibility and privacy (5). Agreement and terms references, privacy and disclosure guidance, authorisation evidence that travels with the transaction, eligibility credentials and machine-readable privacy capabilities for clean-room activation.
Buyer selections and field mutability (3). Where the buyer writes its selection, who computes derived fields, and how a seller catalog option is addressed.
Creative and asset validation (2). Validating asset formats at submission, and keeping creative previews from sending production tracking.
Documentation and examples (2). Expanding workstream references, and bringing the worked examples into line with the field tables.
Event feedback (1). The maintainer's record of feedback from the Agentic Bootcamp.

Alongside these filings, the seven open questions the working group flagged as undecided were tracked as separate issues, most of which drew replies. They range from whether per-field mutability belongs in 3.0 to whether the format registry needs audio, CTV and DOOH entries.

What do the OpenProposal comments have in common?

Read together, most filings ask the draft to say precisely who acts on each field and when. Selections, counter-offers, derived values and status changes all turn on which party writes a value and which can rely on it. That focus tests the README's central claim, that most composition can resolve without a round trip.

A second cluster asks the object model to describe more kinds of inventory and more kinds of evidence. Channel scope, geography, language, brand suitability, measurement and verification each came up from filers declaring seller, buyer or vendor roles. The Agentic Bootcamp summary recorded a proposed position that measurement and verification priority be deferred to 4.0, and states that each item is a proposed position for the working group, not a disposition.

What happens next after the OpenProposal comment period?

IAB Tech Lab's comment process sets out six phases, and the close of public comment, now 10 November 2026, ends phase three. From that point no new comments enter the formal record, and later issues are labelled post-comment and considered for the following draft.

Phase four is adjudication, in which the working group works the queue and every open comment gets a disposition. Phase five publishes the disposition log in full and notifies each commenter on their own issue. Phase six tags a revised draft, which leads either to ratification or to a second comment period, depending on how much moved.

As read on the closing day, the repository had not yet published dates for phases four to six. The README adds that machine-readable schemas will follow the first revision.

What dispositions can an OpenProposal comment receive?

Every comment in the formal record resolves to exactly one of six dispositions: accepted, accepted with modification, rejected, deferred, duplicate or withdrawn. The process commits the working group to written reasons, so a rejection names the tradeoff and a deferral names the workstream or version the point goes to.

The process also states that "implementation feedback outranks opinion", so evidence from building against the draft carries more weight than a reading of it. The README adds that every normative change is recorded in the changelog with the issue behind it, so each change in the revised draft can be traced to the comment that prompted it.

How can teams follow or join the OpenProposal work?

Following the outcome needs nothing more than watching the issue tracker and the disposition log, and commenters are notified on their own issues. Taking part in decisions is separate from commenting: the README points readers to the governance file for who sits on the working group and how decisions are made. For how adoption tends to follow ratification, see Who governs agentic advertising standards, and how do they get adopted?

Why does the OpenProposal comment record matter for agentic media deals?

A comment record with written dispositions gives every implementer the same reference for why a field reads the way it does. That shared reference is what lets a buyer agent and a seller agent, built by different teams, read one proposal the same way.

Alkimi's Marketplace works within IAB Tech Lab's AAMP framework today and is being built to be AdCP compatible, and its DealSheet is written at agreement, timestamped, held by both parties and retrievable by either side independently. The comment period's questions about assent and the agreed version bear directly on that kind of record, which is covered in what OpenProposal means for agentic media planning. The disposition log will show how the working group resolves those questions for the standard itself.

Frequently asked questions

When did the OpenProposal 3.0 public comment period close?

It opened on 22 September 2026 and, after an extension, closes on 10 November 2026. Issues filed afterwards are labelled post-comment and considered for the following draft.

Which companies are contributing to IAB Tech Lab's OpenProposal specification?

IAB Tech Lab develops OpenProposal through a working group, and public comments came from 17 GitHub accounts declaring roles from publisher and SSP to DSP, buyer and verification vendor. Declared roles are self-reported, so the issue tracker is the place to check who filed each comment.

Do you need to be an IAB Tech Lab member to comment on OpenProposal?

No, the README states that a GitHub account is enough to comment. Dispositions are decided by the working group.

What is the OpenProposal disposition log?

It is the formal record of every comment filed during the comment period and what was decided. It is updated as comments are adjudicated and published in full once adjudication is complete.

Is OpenProposal 3.0 a ratified standard?

Not yet, as the README describes the current text as a draft. After adjudication, a revised draft goes either to ratification or to a second comment period.

Which themes drew the most OpenProposal comments?

Inventory, channel and targeting detail drew the most filings (12), followed by object shape and line items (8). Commercial terms and counter-offers, and lifecycle, versioning and assent, drew 7 each.

OpenProposal v3.0: What the Public Comment Period Raised and What Comes Next