API Platform Releases

API Platform 4.3 shipped March 13, 2026. The headline addition is MCP support: your API resources can now be exposed as tools and resources for LLM agents with no extra infrastructure. Alongside that, two quality-of-life improvements stand out — Scalar as an alternative documentation UI, and security checks that fire before the state provider runs. MCP server support The Model Context Protocol is the emerging standard for connecting LLMs to external tools and data sources. 4.3 ships an experimental MCP integration that maps directly onto the API Platform resource model. ...

API Platform 4.2 arrived in September 2025. Three changes stand out: a JSON streamer for large collections that avoids buffering the entire response in memory, an ObjectMapper that replaces the manual wiring in stateOptions-based DTO flows, and autoconfiguration of #[ApiResource] without explicit service registration. JSON streamer for large collections The default Symfony serializer builds the full response in memory before writing it to the output. For a collection of 10,000 items, this means allocating a PHP array, serializing it to a string, and keeping both in memory until the response is flushed. At scale, this is the source of the OOM errors that force people to add pagination everywhere. ...

API Platform 4.1 arrived in February 2025 with a batch of features that are less about new capabilities and more about making the existing ones production-ready. Strict query param validation gets a first-class property. OpenAPI gains a mechanism for splitting large APIs into separate specs. GraphQL gets the abuse prevention controls it was missing. Strict query parameter validation 3.3 introduced query parameter validation as opt-in. 3.4 deprecated the loose behavior. 4.1 formalizes it with a native strictQueryParameterValidation property on resources and operations: when set to true, unknown query parameters return 400. ...

API Platform 4.0 shipped nine days after 3.4, in late September 2024. The version number is honest: there is no new architecture, and the migration from 3.4 is short if you resolved the deprecations. What makes this a major is the scope change — API Platform is no longer a Symfony-only framework — and one opinionated default that reverses six years of PUT behavior. Laravel as a first-class target Since its first release, API Platform was built on Symfony. The HTTP layer, metadata, serializer, and Doctrine bridge all assumed Symfony’s container, event dispatcher, and request lifecycle. Laravel users could run API Platform through a thin adapter, but filters, security, and Doctrine integration did not work on Eloquent. ...

API Platform 3.4 landed in September 2024 as the last minor before the 4.0 jump. The headline feature is BackedEnum as full resources — not just a typed field, but an enum that is itself an API endpoint. BackedEnum as API resources Since PHP 8.1, BackedEnum classes have a fixed set of cases with string or integer backing values. API Platform 3.4 lets you put #[ApiResource] directly on a BackedEnum: ...

API Platform 3.3 shipped in April 2024 with a set of targeted additions. None of them reshape the architecture — 3.2 already closed that chapter. What 3.3 adds is control over things that were previously either hardcoded or required a workaround: response headers, link visibility on sub-resources, and webhooks in the generated spec. Declarative header configuration Before 3.3, setting custom response headers required either a custom processor that modified the response object or a Symfony event listener on kernel.response. Both approaches worked but lived outside the resource definition. ...

API Platform 3.2 arrived in October 2023 with three changes that pushed the state model further: errors became resources, sub-resources came back in a form that actually fits the architecture, and the last legacy extension point — event listeners — was formally replaced. Errors as resources Before 3.2, error handling was outside the resource model. Exceptions were caught by a Symfony event listener and converted to a response, with limited control over the shape of the output. ...

Four months after 3.0, API Platform 3.1 arrived with the first batch of features built on the new state model. Not every change is dramatic, but one of them solves a problem that drove a lot of convoluted workarounds in 2.x: your API resource no longer needs to be your Doctrine entity. The resource/entity split In 2.x, API Platform worked best when your API resource and your persistence model were the same class. Using a DTO as the API surface was possible through the Input/Output DTO system, but that system was removed in 3.0 — it complicated the state model without enough benefit. ...

API Platform 3.0 arrived in September 2022 with Symfony 6.1 as a hard minimum and a core architecture that looked nothing like 2.x. The migration guide is long. The reason it’s long is interesting. The old model had a conceptual leak. DataProviderInterface and DataPersisterInterface were called for every HTTP request, but the provider received the operation context as a hint — not as a contract. A collection provider and an item provider were separate interfaces, but both lived in the same mental bucket: “things that return data.” The HTTP layer knew what was being requested; the provider had to reconstruct that knowledge from context clues passed in the $context array. ...