Data API layers
Each provider is profiled from its own documentation, with the source recorded against every figure. These four all put an API in front of data you already have, and then disagree about almost everything else — one bills per model, one per request, and two per plan at prices two orders of magnitude apart.
Data API layers
| Provider | Entry paid plan | Self-hostable | Pricing model |
|---|---|---|---|
| AWS AppSync | None. AWS states there are no minimum fees and no mandatory service usage: the bill is $4.00 per million query and data-modification operations, $2.00 per million real-time updates and $0.08 per million connection-minutes, plus EC2-rate data transfer. | Not documented | Purely per request, with no plan tier: query and data-modification operations, real-time updates and connection-minutes are each metered and priced separately. |
| Directus | $599/month billed monthly for Team, or $499/month on an annual commitment. It buys 10 SSO seats, 50 collections and 20 flows. | Supported | Flat monthly plans bounded by user seats, collections and flows rather than by requests or data volume. Cloud hosting is an add-on on every tier, including the paid ones. |
| DreamFactory | $1,500/month for DF Linux Lite, billed annually — no monthly-billing rate is published. It includes a single connector of your choice and unlimited roles, keys, API creation and API requests. | Supported | Flat annual plans bounded by how many connectors you may use, not by requests: the entry paid tier states unlimited roles, keys, API creation and API requests against a single connector. |
| Hasura | DDN Base starts at $5 per active model per month — a per-model rate rather than a plan fee, so no magnitude is recorded. Hosting third-party and code connectors is separate, at $0.075/vCPU-hour and $0.0075/GiB-hour. | Supported | Per active model, per month, with connector hosting billed separately by vCPU-hour and GiB-hour. API requests and concurrent users are not metered. |
Which to consider
GraphQL over AWS data sources when you want no floor on the bill: no minimum fees, no mandatory usage, $4.00 per million query and data-modification operations, and WebSocket subscriptions priced separately at $2.00 per million updates.
An existing SQL database that needs both an API and people editing it, where advanced role-based access control on the free Core plan does the job within 3 seats and 25 collections.
Generating REST APIs across a mixed estate — databases, file stores, SaaS and SOAP — behind one contract, self-hosted, with role-based access control and API key management included from the entry paid tier.
Putting one GraphQL API over several data sources at once when the free tier's terms matter more than the paid one's: unlimited models at any scale, no cap on API requests or concurrent users, and self-hosting with the v3 engine, all at $0.