Quick answerRead-only API access for a customer's own AI agent should be priced by query volume and data breadth, not bundled free into an existing plan tier, because an autonomous agent calling your API on a schedule or in response to its own triggers generates fundamentally different load patterns than a human clicking through a UI. Scope it with a dedicated, narrower permission set than your general API, since a well-behaved human rarely hits every readable endpoint in sequence but a poorly designed agent might, and require the customer to register the specific agent and its calling pattern before granting access, not just issue a generic read-only API key.
Why read-only still needs its own pricing model
It is tempting to treat read-only access as low-risk enough to bundle for free, since the agent cannot change anything in your system. That reasoning holds for liability but not for cost or product design. An autonomous agent reading your API does not behave like a human user: it can poll on a fixed interval regardless of whether anything changed, fan out a single customer request into dozens of underlying calls to assemble context, and run continuously rather than in the bursts typical of human browsing sessions. All of that consumes real infrastructure capacity even though nothing is being written.
Price read-only agent access on the dimensions that actually drive your cost and product risk: request volume, the breadth of data the agent can query in a single session, and the freshness requirement (real-time reads cost more to serve reliably at scale than reads tolerant of a caching layer). A tiered read-only API plan, separate from your primary product pricing, lets you charge for this usage transparently rather than absorbing it as unpriced infrastructure load or, at the other extreme, blocking it entirely and losing the integration.
Scope the permission set narrower than your general API, deliberately
Even though the customer's agent cannot write anything, a read-only key that exposes your full data surface is riskier than it looks, because a customer's agent (or a compromised version of it) can enumerate and exfiltrate far more data, far faster, than a human ever would through the UI. Build a distinct, narrower read-only permission set specifically for agent access, scoped to the fields and endpoints a legitimate integration actually needs, rather than reusing your existing read-only API key type designed for human-operated integrations.
Require the customer to specify what their agent is trying to accomplish at registration time, and grant only the endpoints that use case requires, with the ability to request an expansion later rather than defaulting to broad access. This is a lighter version of the safeguards needed for the reverse direction, an inbound agent-to-agent integration where a customer's agent or automation calls yours autonomously, which requires assuming the caller can misbehave and building rate limits and scope restrictions accordingly. Read-only access is lower-stakes than that scenario since nothing can be written, but the same assume-misbehavior posture on scope still applies.
How this differs from write access, and why it needs its own contract language
A vendor contract covering an agent with write access into your systems needs terms about scoped and revocable write permissions, an audit log the customer can review, and rollback procedures, because a write action can directly damage the customer's own data or account state. Read-only access does not carry that direct damage risk, so pricing and governing it identically to write access over-engineers the read-only case and likely under-prices it, since the write-access contract language is built around a different risk, not around API load and data exposure.
Write a distinct, shorter contract exhibit for read-only agent access: it should cover the data fields in scope, the request-rate limits, the pricing tier tied to volume, and a data-use restriction (the customer's agent may query the data to serve the customer's own use case, not to build a competing dataset or resell access). Keep this separate from the write-access agreement so a customer who only needs read access is not forced to negotiate write-access terms that do not apply to them.
Watch for usage patterns that should trigger a pricing conversation
Set up monitoring on read-only agent traffic specifically, separate from your general API monitoring, watching for polling intervals tighter than your data actually changes (a sign the integration is over-fetching and would benefit from a webhook instead of polling, which is worth offering as a cheaper alternative), and for query patterns that suggest the customer's agent is doing something closer to bulk data extraction than normal operational use. Both patterns are worth a direct conversation with the customer rather than a silent rate-limit or a silent price increase, since the customer's engineering team may not be aware of exactly how their agent is calling your API.
Revisit the pricing tier at renewal based on actual observed usage rather than the customer's original estimate at signup, the same way you would revisit a seasonal or spiky usage pricing plan against real data once a full cycle has run. Read-only agent usage in particular tends to grow as the customer's own agent takes on more responsibility over time, so a pricing model that only checks in at initial signup will systematically under-price the relationship within a year or two.
FAQ
Should read-only agent access ever be free at low volume?
A free tier for low-volume read-only access is reasonable and can serve as a natural on-ramp for smaller integrations, as long as the tier boundary is defined by actual request volume and data breadth, not just labeled as free because it is read-only. Set the free tier's ceiling low enough that it does not absorb meaningful infrastructure cost, and make the paid tier's pricing dimensions clear before the customer needs to cross that boundary.
Does a customer's agent need to be individually registered, or can one API key cover any agent the customer builds?
Register the specific agent and its intended calling pattern rather than issuing a generic key the customer can point any future agent at. This matters both for scoping the right permission set to the actual use case and for being able to attribute unusual traffic to a specific integration when troubleshooting or investigating misuse.
What is the biggest mistake companies make when opening up read-only API access to customer agents?
Treating it as a cost-free extension of the existing human-facing API rather than a distinct product surface with its own load profile, permission scope, and pricing model. The technical access looks the same as a read-only human integration, but the usage pattern and risk profile are different enough to warrant separate treatment from day one, not after the first unexpected traffic spike.