diff --git a/.changeset/fix-pause-jsdoc-test.md b/.changeset/fix-pause-jsdoc-test.md
new file mode 100644
index 0000000000..24370e7499
--- /dev/null
+++ b/.changeset/fix-pause-jsdoc-test.md
@@ -0,0 +1,5 @@
+---
+"e2b": patch
+---
+
+fix: update pause() JSDoc and add regression tests for apiKey propagation
diff --git a/packages/js-sdk/src/connectionConfig.ts b/packages/js-sdk/src/connectionConfig.ts
index 298dff1dd9..68a631b443 100644
--- a/packages/js-sdk/src/connectionConfig.ts
+++ b/packages/js-sdk/src/connectionConfig.ts
@@ -84,10 +84,10 @@ export class ConnectionConfig {
   readonly headers?: Record<string, string>
 
   constructor(opts?: ConnectionOpts) {
-    this.apiKey = opts?.apiKey || ConnectionConfig.apiKey
+    this.apiKey = opts?.apiKey ?? ConnectionConfig.apiKey
     this.debug = opts?.debug || ConnectionConfig.debug
     this.domain = opts?.domain || ConnectionConfig.domain
-    this.accessToken = opts?.accessToken || ConnectionConfig.accessToken
+    this.accessToken = opts?.accessToken ?? ConnectionConfig.accessToken
     this.requestTimeoutMs = opts?.requestTimeoutMs ?? REQUEST_TIMEOUT_MS
     this.logger = opts?.logger
     this.headers = opts?.headers || {}
diff --git a/packages/js-sdk/src/sandbox/index.ts b/packages/js-sdk/src/sandbox/index.ts
index 3471dec6cd..043d8bc18b 100644
--- a/packages/js-sdk/src/sandbox/index.ts
+++ b/packages/js-sdk/src/sandbox/index.ts
@@ -572,11 +572,11 @@ export class Sandbox extends SandboxApi {
   }
 
   /**
-   * Pause a sandbox by its ID.
+   * Pause this sandbox.
    *
    * @param opts connection options.
    *
-   * @returns sandbox ID that can be used to resume the sandbox.
+   * @returns true if the sandbox was paused successfully, false if it was already paused.
    *
    * @example
    * ```ts
@@ -585,14 +585,20 @@ export class Sandbox extends SandboxApi {
    * ```
    */
   async pause(opts?: ConnectionOpts): Promise<boolean> {
-    return await SandboxApi.pause(this.sandboxId, opts)
+    return await SandboxApi.pause(this.sandboxId, {
+      ...this.connectionConfig,
+      ...opts,
+    })
   }
 
   /**
    * @deprecated Use {@link Sandbox.pause} instead.
    */
   async betaPause(opts?: ConnectionOpts): Promise<boolean> {
-    return await SandboxApi.betaPause(this.sandboxId, opts)
+    return await SandboxApi.betaPause(this.sandboxId, {
+      ...this.connectionConfig,
+      ...opts,
+    })
   }
 
   /**
diff --git a/packages/js-sdk/tests/sandbox/pause.test.ts b/packages/js-sdk/tests/sandbox/pause.test.ts
new file mode 100644
index 0000000000..e7e32d3df7
--- /dev/null
+++ b/packages/js-sdk/tests/sandbox/pause.test.ts
@@ -0,0 +1,103 @@
+import { assert } from 'vitest'
+
+import { Sandbox } from '../../src'
+import { isDebug, sandboxTest } from '../setup'
+
+/**
+ * Regression test: Sandbox.connect() with explicit apiKey should allow
+ * pause() to succeed even when E2B_API_KEY is not set in the environment.
+ *
+ * See: https://github.com/e2b-dev/E2B/pull/1218
+ */
+sandboxTest.skipIf(isDebug)(
+  'pause() uses apiKey from connectionConfig when E2B_API_KEY is not set',
+  async ({ sandbox }) => {
+    // Save and clear the environment API key
+    const savedApiKey = process.env.E2B_API_KEY
+    delete process.env.E2B_API_KEY
+
+    try {
+      // Get the apiKey that was used to create this sandbox
+      const finalApiKey = savedApiKey
+      if (finalApiKey === undefined) {
+        throw new Error('apiKey must be defined at this point')
+      }
+
+      // Connect to the sandbox with an explicit apiKey (E2B_API_KEY is now unset)
+      const connected = await Sandbox.connect(sandbox.sandboxId, {
+        apiKey: finalApiKey,
+      })
+
+      // Guard: ensure the sandbox is running before we try to pause it
+      assert.isTrue(
+        await sandbox.isRunning(),
+        'sandbox must be running before pause() is called'
+      )
+
+      // pause() should succeed using the apiKey from connectionConfig
+      // rather than requiring E2B_API_KEY to be set
+      const paused = await connected.pause()
+      assert.isTrue(
+        paused,
+        'pause() should return true when successfully pausing a running sandbox'
+      )
+
+      // Verify the sandbox is actually paused
+      assert.isFalse(
+        await connected.isRunning(),
+        'sandbox should be paused after pause()'
+      )
+    } finally {
+      // Restore the environment API key, including empty strings
+      process.env.E2B_API_KEY = savedApiKey ?? undefined
+    }
+  }
+)
+
+sandboxTest.skipIf(isDebug)(
+  'pause() returns false when sandbox is already paused',
+  async ({ sandbox }) => {
+    // Pause the sandbox first
+    const firstPause = await sandbox.pause()
+    assert.isTrue(firstPause, 'first pause() should return true')
+
+    // Verify the sandbox is actually paused before the second attempt
+    assert.isFalse(
+      await sandbox.isRunning(),
+      'sandbox should be paused after first pause()'
+    )
+
+    // Try to pause again - should return false since already paused
+    const secondPause = await sandbox.pause()
+    assert.isFalse(
+      secondPause,
+      'pause() should return false when sandbox is already paused'
+    )
+  }
+)
+
+sandboxTest.skipIf(isDebug)(
+  'pause() works on connected sandbox with apiKey in connectionConfig',
+  async ({ sandbox }) => {
+    const apiKey = process.env.E2B_API_KEY
+    if (apiKey === undefined) {
+      throw new Error('E2B_API_KEY must be set in environment')
+    }
+    const finalApiKey = apiKey
+
+    // Connect to the sandbox using apiKey from connectionConfig
+    const connected = await Sandbox.connect(sandbox.sandboxId, {
+      apiKey: finalApiKey,
+    })
+
+    // Ensure the sandbox is running before pausing
+    assert.isTrue(await sandbox.isRunning())
+
+    // Pause the connected sandbox
+    const paused = await connected.pause()
+    assert.isTrue(paused, 'pause() should succeed on connected sandbox')
+
+    // Verify it's paused
+    assert.isFalse(await connected.isRunning())
+  }
+)