Argyle vs PayFit

Argyle

Graded on the REST API. One OpenAPI file covers 91 operations, llms.txt indexes Markdown docs, and a Sandbox with sample users comes with a Console sign-up. Every payroll connection needs the worker to sign in through Link. No prices are published, no idempotency keys were found, and API keys carry no per-key scopes.

PayFit

A public OpenAPI 3.0 file, llms.txt and scoped keys let a paying customer's agent read payroll outputs and write absences. The API cannot run or approve a payroll, new partner integrations are not being accepted, and no idempotency keys or SDKs were found.

Argyle

1. Send HTTP Basic auth with api_key_id as the username and api_key_secret as the password. Sandbox keys fail with 401 on Production and the reverse
2. Create the user with POST /v2/users and an external_id, then look it up by external_id before retrying. No idempotency key was found
3. Do not read data straight after an account connects. Wait for the account and data webhooks, or for the verification status, before fetching records
4. Follow the full URL in next when paging. Do not build cursor values or fetch pages in parallel. limit defaults to 10 and stops at 200
5. Stay under 50 requests a second. On 429, queue the request and retry later, not at once
6. Treat DELETE /v2/users/{id} as permanent. It removes every resource tied to that user, with no confirmation step

PayFit

1. Have a company admin create the key at app.payfit.com/integrations/hub/api with only the scopes the task needs. The key is shown once
2. POST the key to https://oauth.payfit.com/introspect to get company_id, then call https://partner-api.payfit.com/companies/{companyId}/...
3. Page lists with nextPageToken and maxResults, which defaults to 10 and stops at 50
4. Check before repeating a failed POST. There is no idempotency key, and POST /absences creates an absence that is already validated
5. A collaborator or contract created through the API stays incomplete until an HR admin finishes it in the PayFit app, and a new contract takes 2 to 5 minutes to appear