diff --git a/src/lib/app.tsx b/src/lib/app.tsx
index fdd9742..375607a 100644
--- a/src/lib/app.tsx
+++ b/src/lib/app.tsx
@@ -121,6 +121,9 @@ export function App({
   const { isRawModeSupported } = useStdin()
   const projectRef = useRef<ProjectInfo>(detectProject(root))
   const attemptRef = useRef(0)
+  // The key this run actually connected with. Downstream steps read this
+  // instead of the environment, which may hold a key for another workspace.
+  const apiKeyRef = useRef<string | null>(null)
 
   const [dimensions, setDimensions] = useState({
     rows: stdout?.rows ?? 24,
@@ -331,6 +334,7 @@ export function App({
     source: 'project' | 'cli' | 'browser' | 'pasted',
     location: string | null,
   ): void => {
+    apiKeyRef.current = apiKey
     setWorkspace(settledWorkspace)
     saveConnection(root, {
       workspace: settledWorkspace,
@@ -429,12 +433,11 @@ export function App({
             !cancelled && setBrowser((b) => ({ ...b, received: true })),
         })
         if (cancelled) return
-        setWorkspace(result.workspace)
         addMessage({
           tone: 'ok',
           text: `Connected · workspace ${result.workspace.name}`,
         })
-        advanceAfterAuth()
+        settleOn(result.workspace, result.api_key, 'browser', '.env')
       } catch (error) {
         if (!cancelled) {
           setPhase({
@@ -471,9 +474,8 @@ export function App({
       try {
         const result = await verifyAndSaveKey(root, apiKey)
         if (cancelled) return
-        setWorkspace(result.workspace)
         addMessage({ tone: 'ok', text: `Workspace: ${result.workspace.name}` })
-        advanceAfterAuth()
+        settleOn(result.workspace, result.api_key, 'pasted', '.env')
       } catch (error) {
         if (cancelled) return
         const message =
@@ -610,8 +612,11 @@ export function App({
     if (phase.t !== 'analyze') return
     let cancelled = false
     const run = async (): Promise<void> => {
-      const found = findExistingApiKey(root)
-      if (found == null) {
+      // Prefer the key this run connected with: re-reading here would pick up
+      // SEAM_API_KEY, which can belong to a different workspace than the one
+      // just chosen, and silently plan the integration against that one.
+      const apiKey = apiKeyRef.current ?? findExistingApiKey(root)?.api_key
+      if (apiKey == null) {
         addMessage({
           tone: 'warn',
           text: "Couldn't find your Seam API key to plan the integration.",
@@ -622,7 +627,7 @@ export function App({
 
       let currentSession: WizardInferenceSession
       try {
-        currentSession = await exchangeWizardInferenceToken(found.api_key)
+        currentSession = await exchangeWizardInferenceToken(apiKey)
       } catch (error) {
         if (!cancelled) {
           addMessage({
diff --git a/src/lib/steps/authenticate.test.ts b/src/lib/steps/authenticate.test.ts
new file mode 100644
index 0000000..2869166
--- /dev/null
+++ b/src/lib/steps/authenticate.test.ts
@@ -0,0 +1,58 @@
+import { mkdtempSync, readFileSync, rmSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+
+import { afterEach, beforeEach, expect, test, vi } from 'vitest'
+
+const { get } = vi.hoisted(() => ({ get: vi.fn() }))
+
+vi.mock('@seamapi/http', () => ({
+  isSeamHttpApiError: () => false,
+  isSeamHttpUnauthorizedError: () => false,
+  SeamHttpInvalidTokenError: class extends Error {},
+  SeamHttpWorkspaces: class {
+    get = get
+    client = { post: vi.fn() }
+  },
+}))
+
+const { verifyAndSaveKey } = await import('./authenticate.js')
+
+const workspace = {
+  workspace_id: 'workspace-1',
+  name: 'Acme',
+  is_sandbox: false,
+}
+
+let dir = ''
+
+beforeEach(() => {
+  dir = mkdtempSync(join(tmpdir(), 'seam-wizard-'))
+  vi.clearAllMocks()
+})
+
+afterEach(() => {
+  rmSync(dir, { recursive: true, force: true })
+})
+
+// The run has to carry the key it verified. Returning only the workspace left
+// the caller to re-read SEAM_API_KEY, which may belong to another workspace.
+test('verifyAndSaveKey returns the key it verified', async () => {
+  get.mockResolvedValue(workspace)
+
+  const result = await verifyAndSaveKey(dir, 'seam_pasted_key')
+
+  expect(result.workspace).toBe(workspace)
+  expect(result.api_key).toBe('seam_pasted_key')
+})
+
+test('verifyAndSaveKey returns the trimmed key it saved, not the raw input', async () => {
+  get.mockResolvedValue(workspace)
+
+  const result = await verifyAndSaveKey(dir, '  seam_padded_key\n')
+
+  expect(result.api_key).toBe('seam_padded_key')
+  expect(readFileSync(join(dir, '.env'), 'utf8')).toContain(
+    'SEAM_API_KEY=seam_padded_key',
+  )
+})
diff --git a/src/lib/steps/authenticate.ts b/src/lib/steps/authenticate.ts
index e192464..e8d807e 100644
--- a/src/lib/steps/authenticate.ts
+++ b/src/lib/steps/authenticate.ts
@@ -4,6 +4,7 @@ import { findExistingApiKey, saveProjectApiKey } from 'lib/env-file.js'
 
 export interface AuthResult {
   workspace: SeamWorkspace
+  api_key: string
 }
 
 export interface ExistingKeyResult {
@@ -55,7 +56,7 @@ export async function verifyAndSaveKey(
   const trimmed = apiKey.trim()
   const workspace = await getWorkspaceForApiKey(trimmed)
   saveProjectApiKey(root, trimmed)
-  return { workspace }
+  return { workspace, api_key: trimmed }
 }
 
 export function saveVerifiedKey(root: string, apiKey: string): void {
diff --git a/src/lib/steps/connect-web.ts b/src/lib/steps/connect-web.ts
index 3dd19c1..d2307f7 100644
--- a/src/lib/steps/connect-web.ts
+++ b/src/lib/steps/connect-web.ts
@@ -14,6 +14,7 @@ const CALLBACK_TIMEOUT_MS = 5 * 60 * 1000
 
 export interface WebConnectResult {
   workspace: SeamWorkspace
+  api_key: string
 }
 
 // Progress callbacks so the Ink UI can render the handoff without any logging
@@ -110,7 +111,7 @@ export async function connectViaWeb(
 
   const workspace = await getWorkspaceForApiKey(payload.api_key)
   saveProjectApiKey(root, payload.api_key)
-  return { workspace }
+  return { workspace, api_key: payload.api_key }
 }
 
 function respondJson(