GraphQL API tools cover four different jobs: serving a schema, joining several services into one graph, caching and protecting a live API at the edge, and writing or testing queries. Decide which job you're hiring for first, because a federation platform won't help a single small API and a query client won't serve anything.
Not every tool that turns up for a GraphQL search serves GraphQL itself. Some sit in front of an API you already run, some join many services into one graph, and one is simply where you write and test queries. That split matters more than any feature list, so this page answers the questions that sort a backend developer or technical founder into the right group first, then lists eight tools in no particular order.
Questions that sort the GraphQL field
Do you need a server, a federation layer, an edge layer or a client?
Start with what already exists. If you have a database and no API yet, you want a server or a schema-to-API generator. GraphQL Yoga is an open source server you can host yourself, and Graphile (PostGraphile) builds GraphQL APIs backed primarily by PostgreSQL, which suits teams whose data already lives there.
If several teams each run their own service and you want one graph across them, that's federation. WunderGraph Cosmo is an open source federation platform with schema composition checks, and Apollo GraphOS is pitched at connecting the systems a company already runs into one architecture.
If the API is live and the trouble is load or abuse, an edge layer is the job. Stellate sits in front of a GraphQL API to cache it, protect it and show metrics. And if you mostly need somewhere to write, run and share queries, Altair GraphQL Client is a query client with environments, schema doc search and pre-request scripts.
Why does every big GraphQL homepage now talk about AI?
Because the vendors have changed what they lead with. Hasura's homepage now opens with PromptQL and puts its GraphQL engine second. Apollo pitches GraphOS as one architecture for agents, AI experiences and applications. Grafbase says it's the first GraphQL federation platform to natively support Model Context Protocol, known as MCP.
None of that means these products have stopped doing GraphQL. It does mean the page you land on may describe a different product from the one you came for, so go looking for the GraphQL engine or federation page itself before you judge. Meanwhile the small open source projects in this list, the two servers and the query client, still describe plain GraphQL jobs, which can make them easier to evaluate quickly.
How much does open source matter here?
More than in many categories. Several of these eight describe themselves as open source, and one federation platform promises no lock-in. If your graph will outlive the team that builds it, being able to self-host or move the server is a real consideration, so note which tools say they can be self-hosted.
Can one small schema show the difference between two tools?
Yes, and it's the fastest honest trial you can run. Take a slice of your real schema, perhaps one type with a relationship and one mutation, and stand it up in two tools from the same job. Then write the three queries your front end runs most often and see which setup you understand better at the end of the day. For federation, try composing two small services and break the schema on purpose to see how each platform's checks respond.
For an edge layer, point it at a staging API and compare what you can see before and after. For a client, import your schema and see how quickly a new developer can find the field they need.
Eight GraphQL tools, A to Z
| Tool | Kind of tool | Who it suits |
|---|---|---|
| Altair GraphQL Client | Query client | Developers writing, testing and sharing queries |
| Apollo GraphOS | GraphQL platform and federation | Companies joining many existing systems |
| Grafbase | Federation and API governance | Federation teams who also want MCP support |
| Graphile (PostGraphile) | Postgres-backed GraphQL | Teams whose data lives in PostgreSQL |
| GraphQL Yoga | Open source GraphQL server | Developers who want a self-hosted server |
| Hasura | Instant GraphQL engine | Teams wanting a GraphQL engine for their APIs |
| Stellate | Edge caching and security | Teams caching and protecting a live GraphQL API |
| WunderGraph Cosmo | Open source federation | Teams wanting open source federation |
Listed in no particular order beyond the alphabet; each line sticks to what the maker says.
Altair GraphQL Client
Best for: Writing and testing queries with environments, schema doc search, file upload and pre-request scripts, plus query collections you can export for your team, per the vendor.
Apollo GraphOS
Best for: Companies connecting the systems they already run into one GraphQL architecture; the vendor pitches it for agents, AI experiences and applications.
Grafbase
Best for: Federation teams after governance, observability and extensions; the vendor says it's the first GraphQL federation platform to natively support Model Context Protocol.
Graphile (PostGraphile)
Best for: Postgres shops that want GraphQL APIs backed by their database, from crowd-funded open source projects that also include the Grafast execution engine.
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GraphQL Yoga
Best for: Self-hosting a GraphQL server from The Guild, part of its Hive ecosystem; the vendor calls it fully featured and designed for effortless setup.
Hasura
Best for: Teams after a GraphQL engine for their APIs from a vendor that now sells its PromptQL AI product alongside it.
Stellate
Best for: Putting an edge layer in front of an existing GraphQL API to cache it, protect it and show metrics on it.
WunderGraph Cosmo
Best for: Building and running a supergraph on open source federation with schema composition checks; the vendor promises governance and no lock-in.
Where a small backend team should begin
Reach for the smallest tool that does the job in front of you. A single API over one database rarely needs federation on day one, and a self-hosted server plus a good query client will carry a small team a long way. Add federation when separate teams own separate services, and an edge layer when the live API needs caching or protection. If you're moving off an instant GraphQL engine, my list of alternatives to that kind of engine goes deeper on that one job, and these API testing tools help once the API is running.
Do you make GraphQL servers, gateways or developer tools? Tool makers can ask to be considered for a featured place on this list.
Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.
Frequently asked questions
Is GraphQL a replacement for REST?
Not necessarily. Plenty of teams run both, using GraphQL where front ends need flexible queries and REST where a simple fixed endpoint does the job.
What is GraphQL federation?
Federation joins several GraphQL services, often owned by different teams, into one graph that clients query as if it were a single API. It's useful when no single team owns all the data.
Do I need a separate GraphQL client tool?
You can run queries from many places, but a dedicated client makes it easier to manage environments, browse the schema and share collections of queries with the rest of the team.
Can I self-host a GraphQL server?
Yes. Several open source servers in this category say they can be self-hosted, which gives you control over where the API runs and what it depends on.
Why would a GraphQL API need an edge layer?
Some GraphQL queries are heavy to run, and one endpoint serves many query shapes. An edge layer can cache responses, protect the API and show you which queries are hitting it.
Should I choose a GraphQL tool because it mentions AI agents?
Only if AI agents are part of what you're building. Judge the GraphQL product on the GraphQL job you have today, and treat AI features as a bonus rather than the reason to buy.
