
Any competent developer can build something that queries assistant APIs on a schedule and logs whether a brand appears. Teams frequently do, then quietly abandon it eight months later. The reasons are worth knowing before starting.
What a basic build involves
A prompt list, scheduled calls to whichever assistant APIs you can access, response storage, and simple parsing to detect brand mentions and extract cited sources. A few days of work for someone competent.
The appeal is real: your own prompts, your own storage, no subscription, and complete control over methodology.
What the API gives you and what it does not
Building on APIs is the obvious approach, and it comes with a structural gap. API models can be given web search tools, but the consumer products layer on their own search behavior, personalization, location handling and interface features. Google's AI Overviews and AI Mode have no API that reproduces what searchers see at all.
That does not make API monitoring useless. It is consistent and cheap, and it shows what a model says about your category given a similar setup. But it should be labeled as what it is, and periodically checked against manual samples from the consumer products.
Where it breaks
- API and product divergence. What an API returns is not always what the consumer interface shows, and your buyers use the interface.
- Parsing brand mentions accurately. Harder than it looks. Partial names, misspellings, possessives and competitor names containing yours all produce false readings.
- Maintenance. Providers change endpoints, formats and models. Something that worked in March stops silently in July.
- Ownership. The person who built it moves on and nobody else understands it.
- Cost. API calls at meaningful sample sizes are not free, and the total can approach a subscription anyway.
When building is the right call
When you need something no vendor offers — unusual prompt structures, integration with proprietary data, or measurement of something specific to your category. When you have genuine engineering capacity that will still exist in a year. Or when data residency requirements rule out third-party tools.
Otherwise the honest comparison is not build versus buy, it is build versus the spreadsheet method, because for most teams a manual routine that survives beats an automated one that decays.
A sensible minimum build
If you do build, keep the first version small:
- A prompt table in a database or sheet, with IDs that never change.
- A scheduled job that runs each prompt several times against the chosen models with web search enabled.
- Storage for full responses and cited URLs, with model name and timestamp.
- Simple matching for your brand and a list of competitors, with a manual review queue for uncertain matches.
- A weekly export to the same sheet your team already uses.
Resist building a dashboard until the data has been useful for a few months. Most internal tools die building the interface, not collecting the data.
Costs to estimate before starting
Estimate API costs honestly: prompts times asks per prompt times models times runs per month times the cost per call, including search tool fees where they apply. Then add engineering time for maintenance, which is the cost teams most often forget.
Compare that figure with a subscription and with the manual method. If the build is cheaper only because maintenance was left out, it is not cheaper.
A middle path
Many teams find a middle path works best: buy a monitoring tool for scale and consistency, and build small internal pieces around it, such as exports into your warehouse, alerts when competitor mentions spike, or a sheet that joins citations with analytics and CRM data. You get the reliability of a vendor and the flexibility of your own data.
Frequently asked questions
Can I build my own AI visibility tracker?
Yes, and a basic version takes a few days. The difficulties are accurate brand-mention parsing, divergence between API responses and the consumer interfaces your buyers actually use, and maintenance as providers change formats.
Is building AEO tooling cheaper than buying?
Often less than expected. API calls at meaningful sample sizes cost real money, and maintenance consumes engineering time indefinitely. The realistic comparison for most teams is building versus a manual routine rather than versus a subscription.
When should a team build rather than buy?
When you need something no vendor offers, when you have engineering capacity that will still exist in a year, or when data residency rules out third-party tools.
Do assistant APIs return the same answers as ChatGPT or Gemini apps?
Not necessarily. Consumer products add their own search, personalization and interface behavior, so API results should be checked against manual samples.
What is the hardest part of building an AI visibility tracker?
Accurate brand and competitor matching in free text, followed by maintenance as models and APIs change.
Sources & further reading
- Overview of OpenAI crawlers — OpenAI Platform docs
- Introducing ChatGPT search — OpenAI
- AI features and your website — Google Search Central


