The ChatGPT ads glossary: A to Z
- Every amount in the Ads API is in micros, one millionth of a currency unit; a 60-unit CPM is entered as 60,000 micros per impression.
- A context hint is free text matched by meaning, not an exact-match keyword; up to 2,000 sit on one ad group.
- Creative goes through review, in_review, approved or rejected, and editing the creative sends it back through review.
- Custom audiences are not available for campaigns targeting the EEA or Switzerland.
- The API has no sandbox, no webhooks and no attribution window parameter on insights requests; Adsonomy's shadow mode covers the missing sandbox and its scheduled sync polls the API in place of webhooks.
- GEO and AEO describe writing for AI systems rather than only for a search results page.
This glossary defines the terms used across the OpenAI Ads API and Ads Manager, alongside the two terms Adsonomy uses for its own product, shadow mode and guardrails, and the two broader industry terms, GEO and AEO, that this guide series is written under. Every OpenAI term below is grounded in the platform's documentation or in live testing against it; nothing here is a number or a benchmark OpenAI has not published.
- A context hint is not a keyword: it describes a situation, and OpenAI matches it by meaning, with no per-hint bid.
- Amounts are always in micros in the API; an impression bid is per single impression, not per thousand.
- Review status, serving issues and bid-too-low diagnostics are three separate things, all worth checking when an ad is not delivering.
- The platform has no sandbox or webhooks; Adsonomy's shadow mode covers the first, and its scheduled sync polls the API in place of the second.
- GEO and AEO are about being quotable by an AI system, the same way SEO is about ranking in a search results page.
A
- Ad account
- The top-level container in OpenAI's Ads API and Ads Manager. One API key maps to one ad account, verified with
GET /ad_account, and every campaign, ad group and ad lives inside it. - Ad group
- The level between campaign and ad that holds the bid strategy, up to 2,000 context hints, and, for a feed-based campaign, the product set. Insights are reported per ad group and also per ad.
- AEO
- Answer engine optimisation: writing and structuring content so an AI answer engine can quote or summarise it directly, favouring self-contained, quotable statements over content that only makes sense in context.
B
- Bid multiplier
- A multiplier of 0.1x to 10x applied to a fixed bid for a matched custom audience at ad group level. It only exists for fixed-bid ad groups and only outside the EEA and Switzerland.
- Bidding type
- The campaign-level choice of what you bid on: impressions, clicks or conversions. It is set alongside a billing event, impression or click, and each ad group's bid strategy.
- Billing event
- What OpenAI actually charges for: an impression or a click. Conversion-optimised campaigns can be billed per click or per impression; impression billing is generally available since 16 September 2026 and is OpenAI's recommended model.
C
- Chat card
- One of the two ad creative types: a title of 3 to 50 characters, a body of up to 100 characters, a square image of at least 640 by 640 pixels, and a destination URL. Any edit sends it back into review.
- Context hint
- A free-text description of a product, use case or need, attached to an ad group, up to 2,000 per group. OpenAI matches hints to the meaning of a conversation; it is not an exact-match keyword.
- Conversion optimisation
- A bidding type that optimises delivery toward a chosen conversion event. Since 16 September 2026, conversion optimisation billed per impression is generally available and is OpenAI's stated recommended model.
- Conversions API
- The server-side conversion reporting endpoint, more reliable than the browser pixel because it is unaffected by ad blockers or closed tabs. Events are deduplicated against the pixel by a shared event ID.
- Custom audience
- An uploaded list of customer identifiers, plain or hashed emails and phone numbers, or Android advertising IDs, used to include or exclude people. Not available for campaigns targeting the EEA or Switzerland.
D
- Daily spend limit
- An account-wide daily ceiling available to postpaid invoice accounts, separate from any individual campaign's own daily or lifetime budget.
E
- Event ID (deduplication)
- The identifier, such as an order number, sent by both the pixel and the Conversions API for the same conversion. OpenAI deduplicates on pixel ID, event name and event ID, so the same outcome is counted once.
F
- Fixed bid
- A bid strategy where the advertiser sets the amount per impression or click directly, in micros, rather than letting a maximise strategy set it. It is the only strategy that supports an audience bid multiplier.
G
- GEO
- Generative engine optimisation: structuring a site and its content so generative AI systems can find, trust and cite it, covering things like clear structured data, self-contained FAQ answers and plain-text sidecars.
- Guardrails (Adsonomy)
- The limits Adsonomy's AI manager, Nomy, operates inside: a daily spend cap, bid and budget ranges, limits on the number of changes, step limits per bid or budget change, cooldowns and protected entities, all set by the customer.
I
- Insights
- The reporting endpoint, available at account, campaign, ad group or ad level, by hour or by day. Hourly rows carry only impressions, clicks and spend; conversions need daily granularity, and sales fields daily or monthly.
M
- Maximise clicks
- A bid strategy where the platform sets the bid to get as many clicks as the budget allows, with no documented bid cap.
- Maximise conversions
- A bid strategy where the platform sets the bid to get as many conversions as the budget allows. It needs a conversion event already tracked and, with impression billing, is OpenAI's recommended model since 16 September 2026.
- Micros
- The unit every amount uses through the API: one millionth of a currency unit. An impression bid is entered per single impression, so a 60-unit CPM is 60,000 micros, not 60,000,000.
P
- Pixel
- The browser-side conversion tracking script, loaded from OpenAI's script domain and initialised with a pixel ID. It reads the oppref click identifier ChatGPT appends after an ad click and attaches it to browser events.
- Product feed
- A shop's catalogue in OpenAI's Agentic Commerce product file schema, delivered by SFTP, a hosted URL or manual upload. Feeds are enabled per ad account by OpenAI.
- Product set
- A subset of a product feed, defined by filters such as brand, product_category, item_id or price, that an ad group is allowed to advertise. Several filters are combined with AND.
R
- Review status
- The state of a piece of creative: in_review, approved, or rejected with a reason. Editing a chat card or product ad template, however small the change, sends it back into review.
S
- Serving issue
- A documented reason an approved, active ad is still not delivering, surfaced by requesting a campaign, ad group or ad with include[]=serving_issues. It is separate from review status and from a bid flagged too low to compete.
- Shadow mode (Adsonomy)
- The mode a newly connected Adsonomy ad account starts in, since the Ads API has no sandbox of its own: every intended change is recorded and nothing is sent to the platform until the customer switches it live.
- Spend limit window
- An account-level date range with its own spend ceiling. An account can carry up to 60 non-overlapping windows, enabled per account by OpenAI, on top of each campaign's own budget.
- Sponsored Agents
- An ad experience OpenAI announced it is testing with select US advertisers on 16 September 2026: after clicking an ad, a person may start a clearly labelled conversation with a business's own agent. Not generally available.
V
- View-through conversion
- A conversion counted from someone who saw an ad but did not click it, within a fixed one-day window, when view-through is available for the account. It is reported separately from click-through conversions: in Ads Manager with a 0 or 1-day view window, and in the API's conversion insights as view_through_conversions.
Frequently asked questions
What is the difference between a context hint and a keyword?
A keyword matches the words someone types into a search box. A context hint is free text describing a product, a use case or a need, and OpenAI matches it to the meaning of a whole conversation, not to exact words. There is no bidding per hint and no report on which prompt an ad appeared against.
What is the difference between GEO and AEO?
Both describe writing for AI systems rather than only for a search results page. GEO, generative engine optimisation, is the broader term for being findable and citable by generative AI. AEO, answer engine optimisation, focuses more specifically on writing content, such as an FAQ, in a form an answer engine can quote directly. The two terms overlap in practice.
What counts as a conversion event a campaign can optimise on?
Only a standard event: page_viewed, contents_viewed, items_added, checkout_started, order_created, lead_created, registration_completed, appointment_scheduled, subscription_created, trial_started, app_installed, app_opened. Custom events can be reported but cannot be set as a campaign's optimisation goal.
Why do amounts show as micros instead of ordinary currency?
Micros are the unit the Ads API uses internally: one millionth of a currency unit. It avoids rounding issues on very small per-impression bids. Ads Manager shows ordinary currency; the conversion to and from micros is a detail of building on the API directly.
What is Adsonomy's shadow mode for?
The Ads API has no sandbox or test mode, so there is nowhere on the platform itself to rehearse an automation safely. Shadow mode is Adsonomy's answer: an ad account in shadow mode keeps working against your data but records what it would have changed without sending anything to the platform, until you switch it live.
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