vercel/ai · error

Sandbox session is not available

Error message

Sandbox session is not available

What it means

Identical to the bash_20241022 variant: the bash_20250124 tool's execute callback throws 'Sandbox session is not available' when no `experimental_sandbox` session is present in the tool-call options. Commands can only be executed through a sandbox.

Source

Thrown at packages/anthropic/src/tool/bash_20250124.ts:87

export function bash_20250124<OUTPUT>(
  options: Omit<Bash20250124Options<OUTPUT>, 'execute'> & {
    execute: Bash20250124Options<OUTPUT>['execute'];
  },
): ProviderDefinedTool<Bash20250124Input, OUTPUT, {}>;
export function bash_20250124<OUTPUT>(
  options: Bash20250124OptionsWithNullableExecute<OUTPUT> = {},
): ProviderDefinedTool<Bash20250124Input, OUTPUT, {}> {
  const { execute, ...rest } = options;

  if (execute === undefined) {
    return bash_20250124_internal({
      ...rest,
      execute: async (
        { command },
        { abortSignal, experimental_sandbox: sandbox },
      ) => {
        if (!sandbox) {
          throw new Error('Sandbox session is not available');
        }

        return await sandbox.run({
          command,
          abortSignal,
        });
      },
    } as Bash20250124Options<Bash20250124DefaultOutput>) as ReturnType<
      typeof bash_20250124_internal<OUTPUT>
    >;
  }

  return bash_20250124_internal({
    ...rest,
    ...(execute === null ? {} : { execute }),
  } as Bash20250124Options<OUTPUT>);
}

View on GitHub (pinned to 69428b1f8b)

Solutions

1. Pass an `experimental_sandbox` session (e.g. from @ai-sdk/sandbox or a custom implementation) in the tool execution options.
2. Remove the bash tool if your runtime cannot supply a sandbox, replacing it with a controlled custom tool.
3. Ensure the sandbox session is created before the agent loop executes tool calls.

Example fix

// before
steps: tools: { bash: bash_20250124({ ... }) } // executed without sandbox
// after
const sandbox = await createSandbox();
await generateText({
  tools: { bash: bash_20250124({ ... }) },
  experimental_context: { experimental_sandbox: sandbox },
});

if (!sandboxSession) {
  throw new Error('bash_20250124 tool requires an experimental_sandbox session');
}
// configure the sandbox before starting generateText/streamText

function hasSandbox(opts: any): opts is { experimental_sandbox: { run: (args: { command: string }) => Promise<unknown> } } {
  return !!opts?.experimental_sandbox && typeof opts.experimental_sandbox.run === 'function';
}

try {
  return await sandbox.run({ command, abortSignal });
} catch (error) {
  if (error instanceof Error && error.message === 'Sandbox session is not available') {
    return { type: 'error', error: 'Initialize an experimental_sandbox session to use the bash_20250124 tool.' };
  }
  throw error;
}

When it happens

Trigger: Using the anthropic bash_20250124 tool (via bashTool) in generateText/streamText where the call options lack experimental_sandbox.

Common situations: Migrating to the newer 20250124 bash tool version without also wiring sandbox configuration; running agents in environments with no sandbox provider installed.

Related errors

• Sandbox session is not available
• Invalid argument for parameter batch: batch must be a suppor
• error.message
• CODE_MODE_HOST_TOOL_ERROR
• CODE_MODE_TOOL_ERROR

AI-assisted analysis of vercel/ai@69428b1f8b (2026-08-30). Data as JSON: /api/errors/968764d16221310c. Report an issue: GitHub.