diff --git a/src/__tests__/env-handler.test.ts b/src/__tests__/env-handler.test.ts
index 1524143..1a26b10 100644
--- a/src/__tests__/env-handler.test.ts
+++ b/src/__tests__/env-handler.test.ts
@@ -208,10 +208,26 @@ scope: 'user',
       ]);
 
       expect(content).toBe(
-        'export API_URL="https://example.com"\nexport TOKEN="abc123"\n',
+        "export API_URL='https://example.com'\nexport TOKEN='abc123'\n",
       );
     });
 
+    it('should shell-quote values containing shell metacharacters', () => {
+      // Values flow from the team repo's env/env.yaml into env.sh, which every
+      // member sources from their shell profile. Quotes / `$` / backticks must
+      // be taken literally and must not break or inject into the sourced shell.
+      const content = handler.generateEnvFile([
+        { key: 'CONN', value: 'a"b$c' },
+        { key: 'GREETING', value: "it's" },
+      ]);
+
+      expect(content).toBe(
+        "export CONN='a\"b$c'\nexport GREETING='it'\\''s'\n",
+      );
+      // No raw double-quote wrapping that the old code produced.
+      expect(content).not.toContain('="a');
+    });
+
     it('should return just a newline for empty variables', () => {
       const content = handler.generateEnvFile([]);
       expect(content).toBe('\n');
@@ -257,8 +273,8 @@ scope: 'user',
       const envShPath = path.join(homeDir, '.teamai', 'env.sh');
       expect(await fse.pathExists(envShPath)).toBe(true);
       const content = await fse.readFile(envShPath, 'utf-8');
-      expect(content).toContain('export TGIT_API_BASE="https://git.woa.com/api/v3"');
-      expect(content).toContain('export MODEL_ENDPOINT="https://api.example.com"');
+      expect(content).toContain("export TGIT_API_BASE='https://git.woa.com/api/v3'");
+      expect(content).toContain("export MODEL_ENDPOINT='https://api.example.com'");
     });
 
     it('should inject source line into shell profile (bash)', async () => {
diff --git a/src/resources/env.ts b/src/resources/env.ts
index 0977f0f..b268635 100644
--- a/src/resources/env.ts
+++ b/src/resources/env.ts
@@ -22,6 +22,16 @@ const EnvYamlSchema = z.object({
 export type EnvVariable = z.infer<typeof EnvVariableSchema>;
 export type EnvYaml = z.infer<typeof EnvYamlSchema>;
 
+/**
+ * Quote a string so it is safe to interpolate into a POSIX shell (bash/zsh/sh).
+ * Wraps the value in single quotes and encodes any embedded single quote as
+ * `'\''`, leaving all other characters (including `"`, `$`, `` ` ``, `\`)
+ * literal. Used when generating env.sh, which every team member sources.
+ */
+function shellQuoteValue(value: string): string {
+  return `'${value.replace(/'/g, "'\\''")}'`;
+}
+
 // ─── Handler ─────────────────────────────────────────────
 
 export class EnvHandler extends ResourceHandler {
@@ -173,9 +183,15 @@ export class EnvHandler extends ResourceHandler {
 
   /**
    * Generate the content of ~/.teamai/env.sh with export statements.
+   *
+   * Values are single-quoted so shell metacharacters in an env value (quotes,
+   * `$`, backticks, `\`, …) are taken literally and cannot break or inject into
+   * the sourced script. An embedded single quote is encoded with the standard
+   * `'\''` sequence. env.sh is sourced from every team member's shell profile,
+   * so values (which originate from the team repo's env/env.yaml) must be safe.
    */
   generateEnvFile(variables: EnvVariable[]): string {
-    const lines = variables.map(v => `export ${v.key}="${v.value}"`);
+    const lines = variables.map(v => `export ${v.key}=${shellQuoteValue(v.value)}`);
     return lines.join('\n') + '\n';
   }