api0.app vs Azure API Center

api0.app combines a no-code API builder with a marketplace for publishing and finding APIs. Its visual builder turns tables or defined fields into typed REST endpoints with request validation and pagination. Supported sources include Postgres, MySQL, SQLite, MongoDB, Google Sheets, CSV uploads and existing REST APIs. Each endpoint has an interactive reference and a downloadable OpenAPI 3.1 specification that updates when the schema changes. Generated APIs are private by default, and marketplace publication is optional. Access features include scoped API keys, secret rotation and rate limits that vary by plan. Publishers can charge per request, offer monthly plans or provide a free tier; the platform meters requests, bills buyers and pays builders monthly after a marketplace fee. The dashboard reports request volume, error rate, p95 latency and revenue by endpoint, including customer-level details. The Free plan costs nothing and includes up to 2 live endpoints and 10,000 requests per month.

Azure API Center has no write-up on Specifiction yet; its figures are above.