diff --git a/dev-packages/e2e-tests/verdaccio-config/config.yaml b/dev-packages/e2e-tests/verdaccio-config/config.yaml
index 6e57ee2ea812..beb758aca018 100644
--- a/dev-packages/e2e-tests/verdaccio-config/config.yaml
+++ b/dev-packages/e2e-tests/verdaccio-config/config.yaml
@@ -74,6 +74,12 @@ packages:
     unpublish: $all
     # proxy: npmjs # Don't proxy for E2E tests!
 
+  '@sentry/effect':
+    access: $all
+    publish: $all
+    unpublish: $all
+    # proxy: npmjs # Don't proxy for E2E tests!
+
   '@sentry/ember':
     access: $all
     publish: $all
diff --git a/package.json b/package.json
index 91bc549e4527..59d0415142c1 100644
--- a/package.json
+++ b/package.json
@@ -60,6 +60,7 @@
     "packages/core",
     "packages/cloudflare",
     "packages/deno",
+    "packages/effect",
     "packages/ember",
     "packages/eslint-config-sdk",
     "packages/eslint-plugin-sdk",
diff --git a/packages/effect/.eslintrc.js b/packages/effect/.eslintrc.js
new file mode 100644
index 000000000000..d37e458c151c
--- /dev/null
+++ b/packages/effect/.eslintrc.js
@@ -0,0 +1,15 @@
+module.exports = {
+  env: {
+    browser: true,
+    node: true,
+  },
+  overrides: [
+    {
+      files: ['vite.config.ts', 'vitest.config.ts'],
+      parserOptions: {
+        project: ['tsconfig.vite.json'],
+      },
+    },
+  ],
+  extends: ['../../.eslintrc.js'],
+};
diff --git a/packages/effect/LICENSE b/packages/effect/LICENSE
new file mode 100644
index 000000000000..fea6013e7dbf
--- /dev/null
+++ b/packages/effect/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Functional Software Inc. dba Sentry
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/packages/effect/README.md b/packages/effect/README.md
new file mode 100644
index 000000000000..a209c930b659
--- /dev/null
+++ b/packages/effect/README.md
@@ -0,0 +1,47 @@
+# Official Sentry SDK for Effect.ts (Alpha)
+
+[![npm version](https://img.shields.io/npm/v/@sentry/effect.svg)](https://www.npmjs.com/package/@sentry/effect)
+[![npm dm](https://img.shields.io/npm/dm/@sentry/effect.svg)](https://www.npmjs.com/package/@sentry/effect)
+[![npm dt](https://img.shields.io/npm/dt/@sentry/effect.svg)](https://www.npmjs.com/package/@sentry/effect)
+
+> NOTICE: This package is in alpha state and may be subject to breaking changes.
+
+## Getting Started
+
+This SDK does not have docs yet. Stay tuned.
+
+## Usage
+
+```typescript
+import * as Sentry from '@sentry/effect/server';
+import { NodeRuntime } from '@effect/platform-node';
+import { Layer } from 'effect';
+import { HttpLive } from './Http.js';
+
+const MainLive = HttpLive.pipe(
+  Layer.provide(
+    Sentry.effectLayer({
+      dsn: '__DSN__',
+      enableLogs: true,
+      enableMetrics: true,
+    }),
+  ),
+);
+
+MainLive.pipe(Layer.launch, NodeRuntime.runMain);
+```
+
+The `effectLayer` function initializes Sentry and returns an Effect Layer that provides:
+
+- Distributed tracing with automatic HTTP header extraction/injection
+- Effect spans traced as Sentry spans
+- Effect logs forwarded to Sentry (when `enableLogs` is set)
+- Effect metrics sent to Sentry (when `enableMetrics` is set)
+
+## Links
+
+<!-- - [Official SDK Docs](https://docs.sentry.io/platforms/javascript/guides/effect/) -->
+
+- [Sentry.io](https://sentry.io/?utm_source=github&utm_medium=npm_effect)
+- [Sentry Discord Server](https://discord.gg/Ww9hbqr)
+- [Stack Overflow](https://stackoverflow.com/questions/tagged/sentry)
diff --git a/packages/effect/package.json b/packages/effect/package.json
new file mode 100644
index 000000000000..dbee14b478a8
--- /dev/null
+++ b/packages/effect/package.json
@@ -0,0 +1,67 @@
+{
+  "name": "@sentry/effect",
+  "version": "10.42.0",
+  "description": "Official Sentry SDK for Effect",
+  "repository": "git://github.com/getsentry/sentry-javascript.git",
+  "homepage": "https://github.com/getsentry/sentry-javascript/tree/master/packages/effect",
+  "author": "Sentry",
+  "license": "MIT",
+  "engines": {
+    "node": ">=18"
+  },
+  "files": [
+    "/build"
+  ],
+  "main": "build/cjs/index.js",
+  "module": "build/esm/index.js",
+  "types": "build/types/index.d.ts",
+  "exports": {
+    "./package.json": "./package.json",
+    ".": {
+      "import": {
+        "types": "./build/types/index.d.ts",
+        "default": "./build/esm/index.js"
+      },
+      "require": {
+        "types": "./build/types/index.d.ts",
+        "default": "./build/cjs/index.js"
+      }
+    }
+  },
+  "typesVersions": {
+    "<5.0": {
+      "build/types/index.d.ts": [
+        "build/types-ts3.8/index.d.ts"
+      ]
+    }
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "dependencies": {
+    "@sentry/core": "10.42.0"
+  },
+  "scripts": {
+    "build": "run-p build:transpile build:types",
+    "build:dev": "yarn build",
+    "build:transpile": "rollup -c rollup.npm.config.mjs",
+    "build:types": "run-s build:types:core build:types:downlevel",
+    "build:types:core": "tsc -p tsconfig.types.json",
+    "build:types:downlevel": "yarn downlevel-dts build/types build/types-ts3.8 --to ts3.8",
+    "build:watch": "run-p build:transpile:watch",
+    "build:dev:watch": "yarn build:watch",
+    "build:transpile:watch": "rollup -c rollup.npm.config.mjs --watch",
+    "build:tarball": "npm pack",
+    "circularDepCheck": "madge --circular src/index.ts",
+    "clean": "rimraf build coverage sentry-effect-*.tgz",
+    "fix": "eslint . --format stylish --fix",
+    "lint": "eslint . --format stylish",
+    "test": "vitest run",
+    "test:watch": "vitest --watch",
+    "yalc:publish": "yalc publish --push --sig"
+  },
+  "volta": {
+    "extends": "../../package.json"
+  },
+  "sideEffects": false
+}
diff --git a/packages/effect/rollup.npm.config.mjs b/packages/effect/rollup.npm.config.mjs
new file mode 100644
index 000000000000..ca36da81392f
--- /dev/null
+++ b/packages/effect/rollup.npm.config.mjs
@@ -0,0 +1,11 @@
+import { makeBaseNPMConfig, makeNPMConfigVariants } from '@sentry-internal/rollup-utils';
+
+export default makeNPMConfigVariants(
+  makeBaseNPMConfig({
+    packageSpecificConfig: {
+      output: {
+        preserveModulesRoot: 'src',
+      },
+    },
+  }),
+);
diff --git a/packages/effect/src/index.ts b/packages/effect/src/index.ts
new file mode 100644
index 000000000000..88781f88051a
--- /dev/null
+++ b/packages/effect/src/index.ts
@@ -0,0 +1,87 @@
+export type {
+  Breadcrumb,
+  BreadcrumbHint,
+  Context,
+  Contexts,
+  RequestEventData,
+  SdkInfo,
+  Event,
+  EventHint,
+  ErrorEvent,
+  Exception,
+  SeverityLevel,
+  StackFrame,
+  Stacktrace,
+  Thread,
+  User,
+  Session,
+  CaptureContext,
+  ExclusiveEventHintOrCaptureContext,
+  Log,
+  LogSeverityLevel,
+  Span,
+} from '@sentry/core';
+
+export {
+  addEventProcessor,
+  addBreadcrumb,
+  addIntegration,
+  captureException,
+  captureEvent,
+  captureFeedback,
+  captureMessage,
+  close,
+  createTransport,
+  lastEventId,
+  flush,
+  getClient,
+  isInitialized,
+  isEnabled,
+  getCurrentScope,
+  getIsolationScope,
+  getGlobalScope,
+  setCurrentClient,
+  Scope,
+  continueTrace,
+  getTraceData,
+  suppressTracing,
+  SDK_VERSION,
+  setContext,
+  setExtra,
+  setExtras,
+  setTag,
+  setTags,
+  setUser,
+  withScope,
+  withIsolationScope,
+  functionToStringIntegration,
+  eventFiltersIntegration,
+  dedupeIntegration,
+  parameterize,
+  startSession,
+  captureSession,
+  endSession,
+  spanToJSON,
+  spanToTraceHeader,
+  spanToBaggageHeader,
+  updateSpanName,
+  metrics,
+  getActiveSpan,
+  getRootSpan,
+  startSpan,
+  startInactiveSpan,
+  startSpanManual,
+  withActiveSpan,
+  startNewTrace,
+  getSpanDescendants,
+  setMeasurement,
+  getSpanStatusFromHttpCode,
+  setHttpStatus,
+} from '@sentry/core';
+
+export {
+  SEMANTIC_ATTRIBUTE_SENTRY_OP,
+  SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN,
+  SEMANTIC_ATTRIBUTE_SENTRY_SOURCE,
+  SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE,
+} from '@sentry/core';
diff --git a/packages/effect/test/index.test.ts b/packages/effect/test/index.test.ts
new file mode 100644
index 000000000000..f774de6eaf24
--- /dev/null
+++ b/packages/effect/test/index.test.ts
@@ -0,0 +1,8 @@
+import { describe, expect, it } from 'vitest';
+import * as index from '../src';
+
+describe('effect index export', () => {
+  it('has correct exports', () => {
+    expect(index.captureException).toBeDefined();
+  });
+});
diff --git a/packages/effect/tsconfig.json b/packages/effect/tsconfig.json
new file mode 100644
index 000000000000..ee81c1a20817
--- /dev/null
+++ b/packages/effect/tsconfig.json
@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "module": "esnext",
+    "outDir": "build"
+  },
+  "include": ["src/**/*"]
+}
diff --git a/packages/effect/tsconfig.test.json b/packages/effect/tsconfig.test.json
new file mode 100644
index 000000000000..9dd90014ef37
--- /dev/null
+++ b/packages/effect/tsconfig.test.json
@@ -0,0 +1,9 @@
+{
+  "extends": "./tsconfig.json",
+
+  "include": ["test/**/*", "vitest.config.ts"],
+
+  "compilerOptions": {
+    "types": ["node"]
+  }
+}
diff --git a/packages/effect/tsconfig.types.json b/packages/effect/tsconfig.types.json
new file mode 100644
index 000000000000..76eb1a9bb7c3
--- /dev/null
+++ b/packages/effect/tsconfig.types.json
@@ -0,0 +1,10 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "declaration": true,
+    "declarationMap": true,
+    "emitDeclarationOnly": true,
+    "outDir": "build/types"
+  },
+  "include": ["src/**/*"]
+}
diff --git a/packages/effect/tsconfig.vite.json b/packages/effect/tsconfig.vite.json
new file mode 100644
index 000000000000..4f2b7371b076
--- /dev/null
+++ b/packages/effect/tsconfig.vite.json
@@ -0,0 +1,9 @@
+{
+  "extends": "./tsconfig.json",
+
+  "include": ["vite.config.ts", "vitest.config.ts"],
+
+  "compilerOptions": {
+    "types": ["node"]
+  }
+}
diff --git a/packages/effect/vitest.config.ts b/packages/effect/vitest.config.ts
new file mode 100644
index 000000000000..ed62557713c1
--- /dev/null
+++ b/packages/effect/vitest.config.ts
@@ -0,0 +1,10 @@
+import { defineConfig } from 'vitest/config';
+import baseConfig from '../../vite/vite.config';
+
+export default defineConfig({
+  ...baseConfig,
+  test: {
+    ...baseConfig.test,
+    include: ['test/**/*.test.ts'],
+  },
+});