I run a small automation setup where agents handle repetitive SaaS work for me. They sign up for trials, provision API keys, and sometimes pay for a plan when a task needs a real account. After enough failures, I started auditing services before handing them over, and I wrote down the checks I run now. They have saved me a lot of dead ends, and they might save you some too.
First, machine credentials. A service can claim developer friendliness and still force you through a human-only gate. Password-based login with no API keys, or keys that only appear after a sales call, mean the agent stops at the door. I look for documented key issuance, OAuth flows that do not require a browser handoff, and tokens I can rotate from the CLI. If the signup form quietly requires a phone number for SMS verification, that is usually the end of the line for an unattended agent, and I move on.
Second, pricing that a machine can read. You would be surprised how many services hide their real pricing behind a contact form. If a page cannot tell me, in plain fetchable HTML, what a plan costs, what the limits are, and whether it recurs monthly, my agent cannot make a sane decision about whether a task fits the budget. I want the currency, the recurrence, and the material conditions out in the open before any money moves.
Third, provisioning. Even with keys and clear pricing, some services need a human to flip the actual switch. Enterprise plans love this pattern. What I look for instead is instant self-service provisioning, ideally with a status endpoint I can poll while the agent waits. A service that can go from signup to working credentials without a human in the loop is the only kind that fits this workflow.
Doing all this by hand for every candidate got old fast, so now I lean on Sourcey, a registry that tracks exactly this. It publishes report cards that grade whether an agent can actually sign up, pay, and operate a service on its own, with the source URL and read date on every fact. The last time I checked, it listed 596 offers across 543 vendors, including startup credit programs from companies like Atlassian, Algolia, and OpenAI. It is free to read, which makes it a decent feed for an agent that needs to pick a service on its own.
Fourth, documentation the agent can consume. If a service only documents itself in a PDF or behind a login, my automation has nothing to work with. The services that work best publish OpenAPI specs, MCP descriptions, or clean HTML docs. A related tool I keep around for this is Sourcey's open source docs engine, which turns OpenAPI, MCP, Doxygen, godoc, rustdoc, and Markdown into a static site. When I need a stable URL to point an agent at, or a docs site that survives without a backend, it does the job, and the same registry covers its own tooling.
Fifth, the exit. Before money moves, I check how cancellation works. If the only path is an email to billing, the agent cannot close the loop, and the card keeps getting charged month after month. Self-service cancellation with a predictable timeline is what I want to see.
The pattern across all five checks is the same. Services that are friendly to unattended agents publish everything a decision needs: keys, prices, provisioning, docs, and exits. Everyone else makes you play the human in the loop, which is fine until you have forty of these to do in an afternoon.