diff --git a/apps/cli-e2e/src/tests/gen.e2e.test.ts b/apps/cli-e2e/src/tests/gen.e2e.test.ts
index 3199feac2..cdb173382 100644
--- a/apps/cli-e2e/src/tests/gen.e2e.test.ts
+++ b/apps/cli-e2e/src/tests/gen.e2e.test.ts
@@ -12,10 +12,16 @@ describe("gen", () => {
     testBehaviour.skipIf(isRecording)(
       "generates typescript types from project",
       async ({ run, projectRef }) => {
-        const result = await run(["gen", "types", "--project-id", projectRef]);
+        // #5212 — with CLAUDECODE=1, piped/redirected output must not include the
+        // plugin hint (would break `gen types > file.ts` and similar captures).
+        const result = await run(["gen", "types", "--project-id", projectRef], {
+          env: { CLAUDECODE: "1" },
+        });
         expect(result.exitCode).toBe(0);
         expect(result.stdout).toContain("export type Json");
         expect(result.stdout).toContain("export type Database");
+        expect(result.stdout).not.toMatch(/claude-code-hint/);
+        expect(result.stderr).not.toMatch(/claude-code-hint/);
       },
     );
 
diff --git a/apps/cli-e2e/src/tests/test-context.ts b/apps/cli-e2e/src/tests/test-context.ts
index 63036b1ef..613360f34 100644
--- a/apps/cli-e2e/src/tests/test-context.ts
+++ b/apps/cli-e2e/src/tests/test-context.ts
@@ -21,11 +21,13 @@ function scenarioSlug(task: { name: string; suite?: { name: string } | null }):
   return prefix + slugify(task.name);
 }
 
+type ExecOptions = NonNullable<Parameters<typeof exec>[2]>;
+
 interface BehaviourFixtures {
   projectRef: string;
   orgId: string;
   workspace: TempDir;
-  run: (cmd: string[]) => Promise<CLIResult>;
+  run: (cmd: string[], execOpts?: ExecOptions) => Promise<CLIResult>;
   runNoProjectId: (cmd: string[]) => Promise<CLIResult>;
   apiUrl: string;
   storageBucket: string;
@@ -38,7 +40,8 @@ interface BehaviourFixtures {
  *  - `projectRef` — a real project ref (record mode) or the replay default
  *  - `orgId` — a real org slug (record mode) or the replay default
  *  - `workspace` — fresh temp dir, auto-disposed after the test
- *  - `run` — pre-configured `exec()` for the current TARGET
+ *  - `run` — pre-configured `exec()` for the current TARGET (optional second
+ *    argument forwarded as `exec` options, e.g. extra `env` entries)
  *  - `apiUrl` — the replay server base URL (for setting up error overrides)
  *
  *  Auto-wires a named scenario for the test before running it, so the replay
@@ -90,7 +93,7 @@ export const testBehaviour = test.extend<BehaviourFixtures>({
       cwd: workspace.path,
       projectId: inject("projectRef") as string,
     });
-    await use((cmd) => exec(harness, cmd));
+    await use((cmd, execOpts) => exec(harness, cmd, execOpts));
   },
 
   runNoProjectId: async ({ workspace }, use) => {
diff --git a/apps/cli-go/internal/utils/misc.go b/apps/cli-go/internal/utils/misc.go
index 7ba482d96..6e164acd9 100644
--- a/apps/cli-go/internal/utils/misc.go
+++ b/apps/cli-go/internal/utils/misc.go
@@ -19,6 +19,7 @@ import (
 	"github.com/spf13/viper"
 	"github.com/supabase/cli/internal/utils/agent"
 	"github.com/supabase/cli/pkg/migration"
+	"golang.org/x/term"
 )
 
 // Assigned using `-ldflags` https://stackoverflow.com/q/11354518
@@ -42,10 +43,17 @@ const SuggestDebugFlag = "Try rerunning the command with --debug to troubleshoot
 const claudeCodeHint = `<claude-code-hint v="1" type="plugin" value="supabase@claude-plugins-official" />`
 
 func SuggestClaudePlugin() string {
-	if agent.IsClaudeCode() {
-		return claudeCodeHint
+	if !agent.IsClaudeCode() {
+		return ""
 	}
-	return ""
+	// Suppress the hint when stdout is non-interactive (redirected to a file
+	// or piped). Without this guard, captured output could be contaminated by
+	// the trailer if anything ever leaks the tag onto stdout, and the
+	// install-prompt UX is only meaningful in an interactive shell anyway.
+	if !term.IsTerminal(int(os.Stdout.Fd())) { //nolint:gosec // G115: stdout fd is a small int on supported platforms
+		return ""
+	}
+	return claudeCodeHint
 }
 
 var (