@effect/platform-node-shared

Patch Changes

• Fix child-process cleanup without forceKillAfter to give remaining process-group members up to one second to exit after the leader exits. Clarify that waiting for the leader has no time limit and never escalates to SIGKILL when forceKillAfter is omitted.

• Release writables created by NodeSink.fromWritable and fromWritableChannel when upstream fails or the sink is interrupted, preserving the original exit cause. Writables using endOnDone: false remain open. Preserve stream body encoding errors in the Node HTTP client instead of reporting transport errors caused by request cleanup.

• Return 413 instead of 400 when buffered or decompressed request bodies exceed their size limit, while preserving 400 for other parse failures. Node HTTP servers drain oversized bodies so the response can reach the client without destroying the socket. Node stream readers expose MaxBytesError and an optional destroyOnOverflow setting; their default destruction behavior is unchanged.

• Classify EPERM errors as PermissionDenied instead of Unknown in Node and Deno platform error handlers.

• Fix NodeStream readable consumers hanging on prematurely closed or already-destroyed streams by failing with ERR_STREAM_PREMATURE_CLOSE.

• Fix Terminal.readLine not echoing input or handling Ctrl+C on a TTY.

• Fix NodeSink.fromWritable hanging when a writable finishes normally before all upstream chunks are written. Write callback errors are mapped through onError, and normal finish releases backpressure waits while empty upstreams still succeed. Keep handling delayed error events during asynchronous destruction to prevent unhandled stream errors.

• Fix NodeSink hanging when a writable is destroyed without an error. Premature closure now fails through onError, while closure after completed writes settles successfully.

• Add FileSystem.lstat, which returns the File.Info of a path without following symbolic links. Custom FileSystem implementations, including those passed to FileSystem.make, must now provide lstat.

• Fix FileSystem.realPath rejecting readable Windows AppContainer paths when an ancestor is inaccessible.

Patch Changes

• Use bigint for 64-bit FileSystem.File.Info metadata. dev is now a bigint, and ino, rdev, nlink, and blocks are Option<bigint>, so file stats no longer fail or drop values outside the safe integer range. Node and Bun read dev, ino, rdev, and nlink as unsigned 64-bit integers. Deno reports these fields as numbers, so values above Number.MAX_SAFE_INTEGER are rounded by Deno before conversion.

• Fix FileSystem.watch to prefer the caller-provided FileSystem.WatchBackend, falling back to the backend captured when the file system layer was built.

• Add Path.resolveWithin(root, input), which resolves a relative path beneath a root and returns Option.none() for traversal escapes and rooted inputs, using the platform's path rules.

• Add filesystem watcher installation notifications and wait for all GraphQL watch subscriptions, including nested directories, before generating. This prevents edits during startup from being missed.

Patch Changes

• Prevent unhandled writable errors when buffered child-process stdin or additional input descriptors are interrupted.

• Support an explicit client servername for TLS socket upgrades without changing hostname behavior when omitted.

• Skip Windows taskkill cleanup for children that have already exited, since their PID may have been reused.

Patch Changes

• Add a noFollow option to FileSystem.open to reject symlinks at the final path component. Supported on Node and Bun on POSIX; Windows and Deno return BadArgument. Add { position } to File.read and File.readAlloc for concurrent reads that leave the cursor unchanged.

• Accept address inputs in Dns.reverse and name server inputs in the platform Dns services, and add Dns.nameServerFromInput.

• Add TLSA records to effect/net/Dns, with a Schema.DnsTlsaRecord schema whose JSON codec encodes the certificate association data as hex. The Node.js Dns service queries them with resolveTlsa (Node.js 22.15 or 23.9 and later); Bun, Deno, and older Node.js versions fail TLSA queries with Unsupported.

• Add experimental Host, Dns, and AddressResolver modules to effect/net for host parsing, DNS queries, and endpoint resolution, with Node, Bun, and Deno services. DNS operations accept and normalize domain-name strings; endpoint resolution also accepts host:port strings. Add scoped IPv6 literals and host and DNS record schemas, including JSON codecs for records.

  Provide the services explicitly; they are not included in the platform *Services layers. Use NodeAddressResolver.layer.pipe(Layer.provideMerge(NodeDns.layer)) to provide both Node services.

• Add DatagramSocket for UDP on Node, Bun, and Deno, and NetAddress.inetAddressFromNativeUnsafe for runtime-reported addresses.

• Add Stdio.stderrIsTerminal with an overridable false default and runtime detection for Node.js, Bun, and Deno.

• Esc now ends terminal key input by default, cancelling CLI prompts with Terminal.QuitError. To keep Esc non-cancelling, pass a shouldQuit predicate to make, such as (input) => input.key.ctrl && (input.key.name === "c" || input.key.name === "d") to quit only on Ctrl+C or Ctrl+D.

Patch Changes

• Tag every module and directly importable export with an explicit @stability. @stability stable follows strict semver, and @stability unstable may receive breaking changes in minor releases.

• Update repository dependencies to their latest compatible releases.

Patch Changes

• Fix duplex socket readers throwing when a pull is interrupted or its scope closes during a read. Preserve consumed bytes in order across pull interruption and normal EOF, while discarding them when the reader scope closes.

• Honor forceKillAfter during scope release after a command leader exits with a non-zero code, so surviving descendants that ignore the termination signal are forcefully killed.

Patch Changes

• Effect 4.0 is the first stable release of Effect v4. It replaces the 4.0.0 beta and release-candidate series, whose per-release notes remain below under the 4.0.0-beta.* and 4.0.0-rc.* headings. To upgrade from Effect 3, follow the migration guide.

  Packaging and versioning

  • All Effect packages share one version number and are released together. Use the same version of effect and every @effect/* package.

  • @effect/platform, @effect/rpc, @effect/cluster, @effect/cli, @effect/ai, @effect/sql, @effect/workflow, @effect/experimental and similar packages are merged into effect. Separate packages remain only for platforms (@effect/platform-*), SQL drivers (@effect/sql-*), AI providers (@effect/ai-*), framework bindings (@effect/atom-*), OpenTelemetry, Vitest and tooling.

  • Modules such as effect/http, effect/http-api, effect/rpc, effect/cluster, effect/workflow, effect/ai, effect/cli, effect/sql and effect/schema import from effect/<area>. APIs tagged @stability unstable may have breaking changes in minor releases. APIs without a stability tag follow semver.

  • APIs that expose a third-party dependency are tagged @stability unstable, because that dependency's releases can change them. This covers NodeRedis, DenoRedis, BunRedis, @effect/platform-node/Undici and the undici dispatcher APIs, the ws options and re-exports in the platform packages, driver-specific options and clients in @effect/sql-clickhouse, @effect/sql-d1, @effect/sql-libsql, @effect/sql-mssql, @effect/sql-mysql2, @effect/sql-pglite and @effect/sql-sqlite-do, the provider clients, models and generated schemas in the @effect/ai-* packages, @effect/opentelemetry, and the vitest re-export in @effect/vitest.

  • effect has no runtime dependencies.

  • New packages in v4: @effect/platform-deno, @effect/sql-pglite, @effect/ai-openai-compat, @effect/ai-typesafe, @effect/atom-react, @effect/atom-solid, @effect/atom-vue, @effect/openapi-generator and @effect/doctest. @effect/docgen now lives in this repository.

  Core

  • The fiber runtime was rewritten for lower memory use and faster execution, with smaller bundles and better tree-shaking.

  • Services are defined with Context.Service, FiberRef is replaced by Context.Reference, Cause has a flat structure, and many combinators were renamed. See the migration guide for the full list.

  • Software transactional memory is built into Effect.tx, with TxRef, TxQueue, TxHashMap, TxPubSub, TxSemaphore and related Tx* data types.

  • Clock separates wall-clock time from monotonic time.

  • New modules include Semaphore, Latch, LayerRef, ErrorReporter, ByteSize, Newtype and Crypto. Arbitrary is now a native property-based testing module and no longer depends on fast-check.

  Schema

  • Schema v4 is a new implementation with faster parsing, class-based schemas, make constructors on every schema, and effectful decoding with services.

  • SchemaRepresentation powers JSON Schema (Draft-04, Draft-07, 2020-12 and OpenAPI 3.0/3.1) import and export, TypeScript code generation, and AI structured output.

  • SchemaBinary provides a compact binary codec and is the default wire format for cluster transports.

  • Optional JIT and AOT schema compilers are available as experimental modules.

  Platform, HTTP and RPC

  • HttpApi supports typed response headers, streaming and SSE responses, the HTTP QUERY method, HttpApiTest for in-memory testing, and much faster type checking for large APIs.

  • The HTTP modules add static file serving, response compression, rate-limited clients and graceful server shutdown.

  • Socket has a pull-based reader with backpressure and STARTTLS support. Network addresses are modeled by effect/net.

  • RPC serialization is schema-aware and supports server-originated requests and notifications.

  • @effect/platform-deno adds full Deno support. The Node, Bun, Deno and browser packages all provide the platform Crypto service, and the browser package adds IndexedDB support.

  Cluster and Workflow

  • Workflows can be declared with class syntax, and DurableQueue and an in-memory WorkflowEngine are available.

  • Runner memory can be bounded with ShardingConfig limits. Shutdown, entity movement and persisted replies are more reliable.

  SQL

  • @effect/sql-pg uses a built-in PostgreSQL client with pipelining, prepared statements and binary codecs, and no longer depends on pg.

  • @effect/sql-sqlite-node uses Node's built-in node:sqlite and requires Node 22.16 or newer.

  • SqlError exposes structured reasons such as UniqueViolation.

  AI

  • effect/ai adds EmbeddingModel, the DecisionModel classification and rating API, dynamic tools and tool approvals.

  • The MCP server supports protocol versions 2024-11-05 through 2026-07-28, including elicitation, sampling with tools, resource subscriptions and typed tool output.

  • Provider packages cover Anthropic, OpenAI, OpenAI-compatible APIs and OpenRouter.

  CLI, Atom, observability and testing

  • effect/cli adds global flags, command aliases and examples, an interactive wizard mode, and shell completions for Bash, Zsh and Fish.

  • effect/reactivity and the @effect/atom-* bindings add SSR hydration, stale-while-revalidate atoms and serializable RPC and HttpApi queries.

  • The OTLP exporters can be configured with standard OpenTelemetry environment variables, and @effect/opentelemetry aligns logs and spans with the OpenTelemetry specification.

  • @effect/vitest runs property tests with the native Arbitrary module and supports Vitest fixtures.

  Requirements

  • TypeScript 5.9 or newer. TypeScript 7 is recommended.

  • @effect/vitest and @effect/doctest require Vitest 5.

  • @effect/atom-react requires React 19.

  • @effect/platform-deno requires Deno 2.8.3 or newer.