Here is the honest headline about intent data APIs: most intent data is sold as a platform subscription, and the API is a delivery pipe for existing customers. Only a handful of intent sources are true sign-up-and-call APIs. Choosing well starts with knowing which bucket you are shopping in.
I learned this the uncomfortable way. In 2023 a CMO asked me to “just pull the intent data into the warehouse by Friday.” I spent the week discovering there was no faucet to turn. The deliverable became a one-page memo titled “what we can actually call.”
This article is that memo, rewritten in September 2026 after re-reading every vendor’s documentation. It is a map, not a ranking, because ranking products with wildly different access models would be dishonest. One disclosure up front: CUFinder is our product, it appears in the change-signal section, and I will flag it again there.
What Is an Intent Data API?
An intent data API is an endpoint that returns buying-interest signals about companies or people as structured JSON.
Simple definition, messy reality. Because “buying-interest signal” covers everything from a modeled topic score, to a logged pricing-page visit, to a company identified on your own website, to a verifiable public event like a funding round. Different animals, different evidence. For the collection side of the story, I broke down how intent data is collected separately.
But the bigger surprise for most engineers is not the data. It is the door. The biggest B2B intent data vendors do not sell API access the way a data API company does; they sell platforms, and the API comes with the badge. So before comparing schemas, compare who is even allowed to call what.
📌 Access reality: For most intent vendors, the API is a delivery pipe for subscribers, not a product you can buy alone. Budget for the platform first, the API second.
The Five Kinds of Intent Data You Can Get Through an API
Every intent data API I found in September 2026 falls into five buckets:
- Co-op topic surge. A content co-op models which companies are consuming which topics unusually hard. Bombora is the name here.
- Marketplace research signals. Review sites log real research behavior on their own pages. G2 and SourceForge sell it back to vendors.
- Platform scores. ABM platforms attach intent scores to accounts, reachable via API if you subscribe. 6sense and ZoomInfo live here.
- First-party visitor identification. APIs naming the companies that visited YOUR site: Dealfront’s Leadfeeder, Salespanel, HubSpot’s Breeze as the in-CRM cousin.
- Public change signals. Verifiable events (funding, hires, job changes, hiring spikes) queried as intent evidence. Our own signals endpoints and PredictLeads sit here.
Let’s walk each bucket, access reality first, because that is the question vendor homepages answer last.
Co-op Topic Surge: Bombora
Yes, Bombora has real APIs. Its developer portal documents six of them, but you sign in as a customer or partner to use them.
The documented set covers an Intent API (define and manage Signals, then pull the resulting intent data), an Account List API, a Webhooks API for event subscriptions, a Digital Audience API, a Reference API, and an OAuth 2.0 Authentication API that issues the bearer tokens everything else requires. Proper infrastructure. The underlying data product is Company Surge: topic-level surge scoring built from a B2B content co-op.
The catches are equally real. Pricing is not published, and the portal sits behind a sign-in, so a Bombora relationship comes before a Bombora API call. And surge tells you an organization is consuming topic content unusually hard; it does not name the person, and you cannot independently verify the browsing behind the score. You are buying a well-built inference.
Marketplace Signals: G2 Buyer Intent and SourceForge
G2 sells company-level records of who is researching your product or category on G2, and that data genuinely flows through the G2 API.
The documentation is refreshingly concrete. Buyer Intent records carry the buyer company’s name and domain, firmographics, the page type visited (profile, pricing, category, compare, alternatives, competitive pages), daily page views with dates, an activity level, and a buying stage of Awareness, Consideration, or Decision. Delivery spans the my.G2 interface, CSV exports, the API, and documented Snowflake and BigQuery shares.
The access reality: this is for vendors listed on G2, at the product level. Their docs say it plainly: not all G2 plans receive Buyer Intent signals, and some plans receive more signal types than others. Pricing is not published, and the buying signals only cover research happening ON G2, at company grain. Within those walls, though, a pricing-page view is about as honest as third-party intent gets.
SourceForge runs the same play for its marketplace. Its Buyer Intent API is documented as available to AMPLIFY customers and above, returning prospects researching your software, category, or competitors on SourceForge properties, built for CRM and marketing automation import. Same model, different audience skew.
Platform Scores: 6sense and ZoomInfo
There is no standalone 6sense intent feed you can buy as an API. Intent arrives as score fields on APIs that require a 6sense package.
The public docs list six APIs: Company Identification (an IP address in, an identified account out, with firmographics, segments, and scores attached), Company Firmographics, Lead Scoring, a combined variant, People Enrichment, and People Search. Intent lives inside the responses as intent_score (0 to 100), buying_stage, and profile fit. And access is spelled out per API: identification needs the 6sense Platform, scoring needs the Advanced package, enrichment is a paid add-on. Pricing: not published.
That design makes sense once you see what 6sense actually sells: an identity graph plus orchestration, with intent as one ingredient. You do not buy the ingredient. You buy the kitchen. If you are weighing that kitchen against a lighter data-first stack, the CUFinder vs 6sense comparison puts the two models side by side.
🔍 Did you know: In 6sense's public docs, intent_score and buying_stage arrive attached to identification and enrichment responses. There is no standalone topic-feed endpoint on the public list.
ZoomInfo is the same shape from what its public pages show: buyer intent is a platform solution, and an API exists for delivering ZoomInfo data (intent records included) across business systems. The endpoint docs sit behind customer access, so I will not pretend to have reviewed them; licensing comes first and pricing is not published. Already a customer of either platform? Their API is your route. If not, intent alone rarely justifies the ticket. And if you are pricing that ticket, how CUFinder compares with ZoomInfo is worth reading before the sales call.
First-Party Intent: Visitor Identification APIs
First-party intent is the signal you already own: companies visiting your website, identified by reverse IP lookup. And it is the easiest intent to actually get through an API.
Dealfront’s Leadfeeder documents a REST API where customers pull accounts, leads (the identified visiting companies), and visit histories with a token from the settings page; its newer unified API adds richer company records, signals, tags, and contacts. Salespanel takes the same first-party approach: account reveal via reverse IP, behavior tracking, scoring and alerts, with a REST API and webhooks on paid plans. For the Leadfeeder route specifically, our CUFinder vs Leadfeeder side by side covers where each one fits.
HubSpot’s Breeze Intelligence is the packaged cousin: buyer intent surfaced directly inside HubSpot, showing companies visiting your site in your lists and reports. Powerful if you live in HubSpot, but it is an in-CRM feature, not a standalone intent API product.
The trade mirrors the co-op bucket. Evidence quality is the strongest available (these companies really did visit YOUR pages), but coverage is the smallest: only your existing traffic, at company grain, with the person anonymous. First-party intent finds demand you already attracted, never demand you have not touched.
Public Change Signals: Intent You Can Verify
The last bucket drops the inference entirely. Instead of a modeled score, you query observable buying signals: a funding round, a leadership hire, a hiring spike, a champion switching companies. The event is public and checkable; mapping it to intent is your call, made in the open.
Full disclosure, again: CUFinder is our product, so read the next three paragraphs knowing that. Our signals family is four POST endpoints, each authenticated with an x-api-key header and priced in credits per request:
- Company Signals API (
/v3/signals/companies): companies where one of 82 tracked signals just fired (funding, layoffs, hiring surges, rebrands), filtered by window and strength. 2 credits per request. - People Signals API (
/v3/signals/people): the people at companies where a chosen signal fired, for 17 people-level signals like c_suite_hire. 2 credits per request. - Job Changes API (
/v3/signals/job-changes): people who changed roles in a date range, typed as moves, promotions, or first jobs. 1 credit per request. - Company Activity API (
/v3/companies/activities): a company’s recent social posts with text, hashtags, and engagement, for reading what an account is publicly focused on. 2 credits per request.
Access is the differentiator I care most about in this article’s context: you sign up in the dashboard, get a key, and start on free trial credits without a card or a sales call. Request and response shapes for all four live in the Buying Signals API reference, so I will not repeat them here.
And the honest cons, because everyone here got theirs. Change signals are evidence of change, not topic-level research intent: nobody hands you “this account is researching data enrichment,” so you map signal to relevance yourself. Coverage keys off public footprints, so quiet companies emit little. And there is no anonymous-visitor resolution here; that lives in the first-party bucket.
PredictLeads earns a mention here as the pricing-transparency outlier. It sells public-evidence datasets (news events, job openings, technographics, key customers) via API and webhooks, and publishes rates: 100 free calls a month, then from $0.04 per credit at a $40 monthly minimum, sliding to $0.002 at volume. That is what a callable, priceable data API looks like, and it is rarer in the B2B intent data market than it should be.
Side by Side: Who Can Call What
| Source | What the API returns | Who can call it | Pricing | Best fit |
|---|---|---|---|---|
| Bombora | Topic surge scores, account lists, webhooks | Customers and partners (OAuth 2.0 sign-in) | Not published | Enterprise ABM and media targeting |
| G2 Buyer Intent | Companies researching your product or category on G2 | G2 vendors on qualifying plans | Not published | SaaS vendors listed on G2 |
| SourceForge | Prospects researching your software or competitors | AMPLIFY customers and above | Not published | Software vendors on SourceForge |
| 6sense | Intent scores and firmographics on identification and enrichment calls | 6sense platform customers; some APIs are add-ons | Not published | Teams already running 6sense |
| ZoomInfo | Platform data delivery, intent records included | Licensed ZoomInfo customers | Not published | Teams already paying for ZoomInfo |
| Dealfront (Leadfeeder) | Companies identified from your own site traffic, with visits | Customers, via API token | Customer plans | First-party website intent |
| Salespanel | First-party visitor, account, and scoring data | Customers on paid plans | Paid plans | First-party tracking with webhooks |
| CUFinder Signals APIs | Typed change events for companies and people | Anyone; self-serve key, free trial credits | Published credit plans | Developer-first signal workflows |
| PredictLeads | News, hiring, and technology change events | Anyone; 100 free calls a month | Published per-credit rates | Pay-as-you-go change data |
Read the middle column twice. Five of nine rows require a commercial relationship before the first API call. That fact reshapes most “which intent API should we use” conversations.
How to Choose (By Situation, Not by Ranking)
So which intent data API should you pick? Wrong question. The right one: which bucket matches your situation?
- Already on an ABM platform? Use its API. You are paying for that identity graph anyway; a second source before activating the first is how shelfware happens.
- Sell software listed on G2? Marketplace intent is the highest-evidence third-party signal you can buy, because a compare-page view is behavior, not a model.
- Broad-market education motion? Co-op topic surge fits marketing (audiences, prioritization) better than it fits a rep’s Tuesday call list.
- Own real website traffic? Start first-party. It is your cheapest honest signal, and every later source gets judged against it.
- Developer-first, no enterprise contract, need verifiable evidence? Change signals. You can call them this afternoon and audit every record they return.
- Mature GTM team? Combine first-party with ONE more bucket, and spend the energy on weighting and dedup. Signal fusion is the real work.
💡 Pro tip: Price the access model, not the data. Per-credit, per-call, and platform-fee models make completely different workflows sane. A score you cannot afford to query often is not a real-time signal.
And here is the evidence-versus-coverage math per bucket, in honest qualitative terms:
| Bucket | Evidence strength | Coverage | Typical latency | Entry path |
|---|---|---|---|---|
| Co-op topic surge | Modeled inference | Broad | Periodic scoring | Vendor contract |
| Marketplace signals | Real research actions | Narrow (one marketplace) | Daily visit grain | Marketplace vendor plan |
| Platform scores | Modeled, graph-backed | Broad within their data | Per API response | Platform subscription |
| First-party visitor ID | Your own visitors, observed | Smallest (your traffic only) | Near real time | Tool plan plus tracking script |
| Public change signals | Verifiable events | Wide, event-driven | As public footprints update | Self-serve API key |
How I Put This Map Together
Everything above comes from vendor documentation read in September 2026: Bombora’s developer portal listing, G2’s Buyer Intent references, 6sense’s API docs, SourceForge’s pages, Leadfeeder’s API reference, PredictLeads’ published pricing, and our own endpoint docs. I called what I could get keys for (our own, and the free tiers). I could NOT call Bombora, 6sense, or ZoomInfo without contracts, and that access wall is finding number one, not a footnote. Vendors repackage constantly; the references below take you straight to the docs.
Frequently Asked Questions
What is intent data?
Intent data is behavioral evidence that a company may be researching a purchase: content consumption, review-site activity, website visits, or public changes read as buying signals. Quality varies by source; a modeled topic score and a logged pricing-page visit are different kinds of evidence.
Is there a Bombora API?
Yes. Bombora’s developer portal documents six APIs, including an Intent API, webhooks, and audience building, secured with OAuth 2.0. Access is for customers and partners, and pricing is not published, so a Bombora contract comes first.
Does G2 have a buyer intent API?
Yes. G2 delivers Buyer Intent data through its API alongside CSV exports and Snowflake and BigQuery shares. Records include company, page type, visit dates, activity level, and a buying stage. Which signal types you receive depends on your G2 plan.
How does 6sense get intent data, and can I call it?
6sense blends its network’s signals into account-level scores, reached through APIs gated by 6sense packages. There is no standalone topic feed in the public docs; intent_score and buying_stage arrive attached to identification and enrichment responses.
How much does an intent data API cost?
Mostly: not published. Bombora, G2, 6sense, and ZoomInfo price through sales conversations. The published outliers are change-signal vendors: PredictLeads lists per-credit rates from a $40 monthly minimum, and CUFinder publishes credit plans with free trial credits. Treat “not published” as a data point in itself.
What is first-party intent data?
First-party intent data is buying interest observed on your own properties: site visits, content engagement, product usage. Visitor identification APIs like Leadfeeder’s turn anonymous traffic into named companies. Strongest evidence you can get, limited to demand you already attracted.
Can I get intent data in real time via webhook?
Sometimes. Bombora documents a Webhooks API for subscribers, PredictLeads sends followed-company signals to your webhook, and first-party tools alert as visits happen. Change-signal APIs update as public footprints update, so “real time” honestly means “as the world publishes.”
Are intent data APIs GDPR-compliant?
Company-level buying signals are the industry’s main answer: scores and visits get tied to organizations, not named individuals, and co-ops build on publisher consent chains. Change signals draw on public business footprints. But compliance is never inherited: your lawful basis for outreach stays yours to establish.
References and Sources
Every claim about access and fields traces to vendor documentation read in September 2026. Vendors change packaging faster than articles change, so click before you budget.
- Bombora, Developer Portal (API listing and authentication). developer.bombora.com
- G2, Buyer Intent data reference. documentation.g2.com
- G2, Buyer Intent documentation (signal types and plan access). documentation.g2.com/docs/buyer-intent
- 6sense, API documentation. api.6sense.com
- SourceForge, Buyer Intent API documentation. docs.sourceforge.net
- Dealfront, Leadfeeder API reference. docs.leadfeeder.com
- PredictLeads, pricing. predictleads.com/pricing
Start With the Signal You Can Verify
Unsure after all that? Start where the evidence is checkable. Wire up first-party tracking, or pull a week of public change signals, and act on ten accounts. You will learn what intent data is worth to YOUR motion faster than any vendor deck can tell you.
🧠 Remember: An intent score is an inference. A job change, a funding round, or a hiring spike is a fact. Score the inference, verify the fact, and never confuse the two.
The platforms will still be there when you are ready for a bigger contract, and by then you will negotiate knowing what a signal is worth to you. Until then, our endpoint family is in the CUFinder API directory, free trial credits included. Go call something.
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