53 providers and 40 APIs on the network carry the Sandbox tag — a test environment where you can make real calls against fake data before you have an account, a contract, or a reason to trust anyone.
Fifty-three, out of 26,530 providers.
What a sandbox actually removes
The distance between reading about an API and calling it is where most integrations die.
Without a sandbox, evaluating an API means: create an account, verify an email, complete a company profile, request access, wait for approval, generate credentials, and only then discover whether the response shape fits your data model. Several of those steps involve a salesperson. In regulated verticals, some involve a contract.
A sandbox collapses all of it into a curl command. You find out in ninety seconds whether this API does what you need, and the vendor finds out whether you are a real prospect without paying anyone to qualify you.
The economics favour the sandbox on both sides, which makes 53 a genuinely strange number.
The good examples are instructive
Okta’s Cross-App Access, covered on Thursday, runs xaa.dev as a public sandbox for an IETF draft protocol — you can test both the requesting and resource application halves without an Okta contract. That is a company sandboxing a specification, not just a product.
MTN Group, profiled tomorrow, runs momodeveloper.mtn.com as a self-serve portal with a sandbox for its Collection, Disbursements and Remittance APIs — mobile money, in markets where mobile money is the primary financial rail, testable by anyone.
Both are in categories where you would most expect a gate: identity protocols and financial services. Both chose the opposite.
Where sandboxes are scarce and shouldn’t be
The pattern in the catalog is that sandbox availability drops exactly where the integration is hardest and the stakes are highest — payments, banking, healthcare, telecom.
The reasoning is understandable. These are regulated surfaces, the data is sensitive, and access control is a compliance obligation rather than a preference. But the obligation applies to production data, not to a test environment full of synthetic records. Conflating the two produces a common outcome: a developer cannot evaluate a regulated API without a signed agreement, so they build against the competitor who let them try.
The agent argument
This is about to matter more, in a way that has not been widely priced in.
An agent evaluating options among several APIs will, in practice, prefer the one it can successfully call. Not the one with the better pricing page or the more persuasive documentation — the one where a test request returns a 200.
A sandbox is the difference between being considered and being skipped. Onboarding friction has always cost providers developers at the margin. It is about to cost them agent selection outright, and agents do not send a follow-up email asking for access.
Takeaway
53 providers out of 26,530 let you call the API before you commit to it. The best examples are in the most regulated categories — a draft OAuth profile and African mobile money — which undercuts the compliance excuse the rest of the catalog leans on.
Browse the tag at apis.io/tags/sandbox/.