TypeScript Runtime

The public runtime surface comes from:

import * as flo from "flo:runtime";

The module exports these top-level helpers:

• sleep
• time
• vault
• state
• task
• callTool
• browser

JSON-Oriented API Design

Runtime values are JSON-shaped. FloJsonValue includes:

• null
• boolean
• number
• string
• arrays of JSON values
• objects whose values are JSON values

This affects:

• tool inputs and outputs
• flo.state
• child-task input and output
• browser evaluate args and values

Global Helpers

The runtime provides:

• fetch(...)
• URL
• URLSearchParams

That means many integration-oriented tools can work without additional libraries.

Task Context

Use flo.task.getContext<T>() to read durable task context:

type Context = {
  resume_payload?: {
    batch_id?: string;
  };
  custom?: { value: number };
};

const context = await flo.task.getContext<Context>();

The context may include resume data after a suspension flow. When a task resumes, the runtime re-enters the script from its entrypoint instead of restoring the JavaScript stack.

Time and Sleep

Use flo.sleep(ms) to pause a script without blocking the runtime thread.

Use flo.time.formatUnixTimestamp(...) when you need stable date formatting:

const formatted = flo.time.formatUnixTimestamp(1_700_000_000, "YYYY-MM-DD HH:mm:ss", "UTC");

Local Shim Notes

The Node preload shim supports:

• flo.sleep(...)
• flo.time.formatUnixTimestamp(...)
• flo.vault.get(...) with FLO_MOCKS_FILE
• flo.task.getContext(...)
• flo.task.emitEvent(...)
• browser helpers when FLO_LOCAL_BROWSER=1

Other runtime-bound APIs intentionally fail in the local shim so tests do not accidentally depend on unsupported local behavior.

Next: Nested Tool Calls