AWS AppSync cost: per query, per real-time message, per connection

Quick answer

AppSync bills query and data-modification operations (about $4 per million), real-time subscription messages (about $2 per million), and connection-minutes for open subscriptions, plus the cost of the resolvers behind it. Chatty clients, broad subscriptions that fan out to many connections, and long-lived idle connections drive the bill.

AWS AppSync is managed GraphQL, and its pricing reflects GraphQL's shape: you pay for operations and for the real-time machinery. The API charges are usually modest; the larger cost is often the resolvers (Lambda, DynamoDB) the operations trigger.

Operations and real-time

Dimension	Rate (approximate)
Query + data modification operations	~$4 / million
Real-time subscription messages	~$2 / million
Connection-minutes	Per million connection-minutes

Queries and mutations are billed per million operations. Subscriptions add two lines: messages pushed to subscribers, and the connection-minutes those subscribers stay connected. A subscription that fans out an update to thousands of connected clients multiplies the message count.

Watch subscriptions and chatty clients

The real-time features are where AppSync cost grows unexpectedly. A broad subscription that broadcasts every change to many clients generates messages per client per change, and many long-lived idle connections accrue connection-minutes. Scope subscriptions narrowly so clients receive only relevant updates, and close connections that are no longer needed.

The resolvers cost more

Behind each operation is a resolver: a Lambda function, a DynamoDB query, an HTTP call. Those usually cost more than the AppSync operation charge itself, so a query that fans out to expensive resolvers is priced mostly by the backend. Optimize resolvers, cache where possible, and design the schema so common queries hit cheap data sources, the same whole-system thinking as API Gateway cost.

FAQ

How is AWS AppSync priced?

By query and data-modification operations (about $4 per million), real-time subscription messages (about $2 per million), and connection-minutes for open subscriptions, plus the cost of the resolvers (Lambda, DynamoDB) behind each operation. The resolvers often cost more than the API charge.

Why is my AppSync bill high?

Usually real-time subscriptions or resolvers. A broad subscription broadcasting every change to many clients generates messages per client per change, many idle connections accrue connection-minutes, and expensive resolvers behind queries add backend cost. Scope subscriptions narrowly and optimize resolvers.

How do I reduce AppSync cost?

Scope subscriptions so clients receive only relevant updates rather than broad broadcasts, close connections that are no longer needed, optimize and cache resolvers, and design the schema so common queries hit cheap data sources. The resolvers usually dominate cost.

Do AppSync subscriptions cost extra?

Yes. Subscriptions add real-time message charges (per million messages pushed to subscribers) and connection-minute charges (for how long subscribers stay connected), on top of the base query and mutation operations. Broad, high-fanout subscriptions are the common cost surprise.

Is AppSync or API Gateway cheaper?

They serve different needs: AppSync for managed GraphQL with real-time subscriptions, API Gateway for REST and HTTP. Per operation both are modest, and in both the backend resolvers usually cost more than the API charge. Choose by API style and features, then optimize the backend.

Does C3X estimate AppSync cost?

AppSync cost is driven by operations, messages, and connection-minutes, which are usage inputs, plus the resolvers behind them. C3X prices the resolver infrastructure (Lambda, DynamoDB) from your Terraform, and you model API usage for the AppSync charges.

What to do next

Price the resolvers behind your GraphQL API before you deploy. C3X reads your Terraform and prices your resources against a live catalog. Start with the quickstart.