Tested on hundreds of simulations
Each scenario is one YAML file. Simulated users try every edge case before a real one does.
Let users chat with your product on iMessage & WhatsApp, and use it as an MCP in their ChatGPT, Claude.
Backed by
Entrepreneurs First
Illustration: DoorDash, HubSpot and the other brands on this page are examples, not Flow customers, and the numbers are made up.
Ships to
Dashboards at work. Mobile apps for everything else. Click, tap, fill in the form.
Say what they want, the way they'd text a friend, and get it done right there.
ChatGPT and Claude. WhatsApp and iMessage. Personal agents like Instinct and Muse. Any MCP client. A terminal.
One agent, one codebase, every place your users ask.
Ready for production
Each scenario is one YAML file. Simulated users try every edge case before a real one does.
When the model misreads intent or a tool is unclear, Flow suggests a fix.
Every model and tool call, timed and kept, so you see why it said what it said.
Illustration: the numbers are examples, not real results.
For consumer apps
A human-like chat experience. It handles shorthand, second thoughts and two languages in one sentence, then does the thing.
It remembers each customer's chat between conversations, on each channel.
Customers talk, snap and send the way they already do. It understands all of it.
Reminders and follow-ups in each person's time zone, never during quiet hours.
For SaaS
One MCP server from the same codebase, so people use your product where they already work.
Claude Code and Codex drive your product from the terminal.
OAuth per user, so the agent only sees what they can.
Illustration: HubSpot and the other brands are examples, not Flow customers.
Pricing
Put your agent on iMessage with the iMessage API, or build, host and test it with Flow. Both are priced by the people who use them, never by the message.
$0
Try your agent on iMessage today.
Get startedWas $30 now $25 /mo
Your agent on our shared line.
Get started$100$140 /mo
Your agent on its own iMessage number.
Get started$0 forever
Launch to real users in minutes.
Get started$25$125$38$138$68$168$118$218$193$293$343$443$643$743 /mo
$25 Pro + $100 line = $125/mo (two plans)$38 Pro + $100 line = $138/mo (two plans)$68 Pro + $100 line = $168/mo (two plans)$118 Pro + $100 line = $218/mo (two plans)$193 Pro + $100 line = $293/mo (two plans)$343 Pro + $100 line = $443/mo (two plans)$643 Pro + $100 line = $743/mo (two plans)
Scale as your users grow.
Custom
Our team helps you set it up and launch.
Book a callMore questions? See our pricing page.
Who we are
We build Flow ourselves, and we answer every message ourselves. Say hi on LinkedIn or book a call.
Book a callAn AI agent lets customers use your product through a conversation. With Flow Framework you write your product’s jobs as typed tools that call your APIs, so the agent can answer questions and take actions, such as checking an order or booking an appointment, on iMessage, WhatsApp or Telegram.
No. The agent’s tools call whatever you already run: an API, a database or an MCP server. Until those are ready, a tool can return sample data, so you can text the agent on the Telegram sandbox the same day and swap in real calls later.
Someone who can write TypeScript, or a coding agent. Copy the agent instructions at the top of this page into Claude Code, Codex or Cursor and it creates the project, writes the tools and runs the tests. Real data, signed-in actions and payments are usually an afternoon for whoever owns your backend.
Actions run against your real systems, never guessed, and every one is logged so you can audit it. Before a release goes out, Flow runs it against hundreds of simulated users on the paths that matter, ordering, rescheduling, refunds, and people changing their mind mid-sentence.
Every surface has its own review and its own rules, such as WhatsApp's message templates and the ChatGPT and Claude app directories. You submit to each platform under your own account, and the timelines belong to the platforms, so we don't promise them.
Yes. On each channel, the agent keeps the person's conversation there, so they can pick up where they left off. You can delete everything kept about a person at any time.
You do. The threads, the contacts and the orders are yours and export at any time. We do not sell data and we do not train public models on your customers.
Pro comes with $10 of agent credit every month to spend on LLM tokens: your agent's WhatsApp, iMessage and CLI chats, and any LLM calls in your MCPs. Tokens past the $10 are billed at cost, with no markup. Unused credit doesn't roll over.
You get direct access to a few models we have proven for chat, so your agent works well from day one without choosing or setting up a model.
Yes. The Flow Framework lets you plug in your own model and provider, so you're never locked in. When your agent runs on your own model, its usage is billed by your provider, not by us.
Pro is $25 a month with 500 users included. Users past that are priced by range: users 501 to 1,000 cost $0.025 each, 1,001 to 5,000 $0.02, 5,001 to 20,000 $0.015, and past 20,000 $0.01. A user is anyone who uses your agent in a month, through any surface.
Copy the agent instructions at the top of this page into your coding agent, or run npx @flow-engineer/flow new my-agent. Then sign up at flow.engineer for a free trial: 25 people on the shared iMessage line, ever (no monthly reset). No card and no call needed.
The messaging apps around it: WhatsApp, iMessage and Telegram.
Copy the agent instructions and your coding agent does the setup. No card, no demo call.