TL;DR
The best platform depends on who writes the code. If your own agent builds the tool, floo is the strongest fit: it is the only platform of the 15 compared where invite-only sign-in, Postgres, scheduled jobs, and a scoped key per agent are all built in, and an outside agent can ship all of it without a dashboard. floo runs the internal and personal software you build with AI: sign-in for people, API keys for agents, Postgres, storage, and scheduled jobs in one app.
- Agent access is the widest gap. Only floo and Cloudflare give an outside agent its own scoped, revocable key. Most platforms offer only full-access keys.
- Built-in sign-in is common, but often gated. Replit's needs the $100 Pro plan, Railway's needs a $5,000 a month commitment, and Render, Fly.io, Firebase, and Netlify have none.
- Builders are different products. Lovable, Replit, and Bolt build the app with their own agent. floo assumes you bring yours.
- Cloudflare is the closest alternative. It is cheaper and its gate admits any invited email, but its database is SQLite and setup runs through a dashboard.
Every fact below comes from each vendor's own docs and pricing pages, read on October 22, 2026. We traced the same tool through all of them.
What is the task?
An inventory tool for a 3-person team:
- A web page only invited teammates can sign in to.
- A Postgres table of stock.
- A daily job that flags low stock.
- An API key an outside AI agent can use to read and update counts, scoped to the app and revocable without affecting the people.
How do the 15 platforms compare?
| Platform | Invite-only sign-in | Postgres and daily job | Scoped key per agent | Lowest price for this tool |
|---|---|---|---|---|
| floo | Built in, one config line, every plan | Both built in | Yes, per route, with rate limits and a request log | $0 commitment, pay for usage |
| Cloudflare | Built in (Access), email codes | SQLite (D1), cron | Yes (Access service tokens) | $0 to $5 |
| Lovable | Built in, up to 10 people on Free and Pro | Both | No | $0 on Free; Pro $25 |
| Replit | Built in, Pro plan only | Both | No; the gate also blocks agents | $100 for the gate |
| Retool | Built in (org login) | Both, 5 GB database | Partly; one key per workflow | $0 |
| Base44 | Built in, paid plans | NoSQL, cron | Partly; write access also edits the app | $16 |
| Vercel + Supabase | About 448 lines of template auth code | Both | No; secret keys have full access | About $45 (Vercel Hobby is non-commercial) |
| Vercel + Neon | Vercel Authentication, Vercel accounts, Pro | Both | No; bypass secret covers the whole project | $20 (Hobby is non-commercial) |
| Bolt.new | Private sites, paid plans | Postgres; no documented scheduler | No | $18 |
| Railway | Built in only at $5,000 a month; else a provider like Clerk | Both | No | $0 Free with $1 of monthly credit; Hobby $5 |
| Heroku | wwwhisper add-on, $19 a month | Both | No | About $31 |
| Fly.io | None; auth in your app | Both | No | About $40 |
| Render | None; a third-party provider | Both | No | About $13 |
| Firebase | You write it | Postgres via Data Connect, scheduler on Blaze | No | About $9 |
| Netlify | You write it with Identity | Both | No | $9 |
Why does the agent key matter so much?
An internal tool used to have one kind of user: people. Now it has two. The agent that built the tool also uses it, reading counts, updating rows, and running reports. That agent needs its own credential: limited to what it should touch, rate-limited, revocable without signing anyone out, and visible in a log.
Most platforms only offer project-wide keys. Supabase's secret keys bypass row-level security. Vercel's protection-bypass secret covers every deployment in a project. Replit's built-in gate blocks machine callers entirely, so an agent key means making the app public and writing auth yourself.
On floo, you declare which routes accept machine access in floo.app.toml, then mint a key for a named consumer:
floo apps consumers create stock-agent
floo apps keys create stock-agent --consumer stock-agent --scope inventory.write --rate-limit-rpm 60
floo strips the key before your code sees the request and passes the verified consumer's identity instead. Every request the key makes is listed by key ID.
When is floo the right choice?
When you build with your own agent and want the tool to run somewhere private and durable without setting up servers. access_mode = "accounts" puts hosted sign-in in front of the app, floo apps invite adds teammates, and the app reads the signed-in person from request headers with no auth code. Postgres, Redis, file storage, scheduled jobs, and preview environments attach to the same app, and every step is in the floo API, CLI, and MCP server.
The trade-offs: invited people sign in with a floo account, someone adds a card and buys credits before the first deploy, and floo has no visual builder.
When is Cloudflare the right choice?
When cost matters most and SQLite is enough. Cloudflare Access is free up to 50 users, admits invited emails with a one-time code, and its service tokens give each agent a scoped, revocable credential. Setting up Zero Trust happens in the dashboard and asks for a card, and D1 is SQLite rather than Postgres.
When are Lovable or Replit the right choice?
When you want their agent to build the app inside their editor. Lovable's free plan can publish privately to up to 10 people per project, which is a strong start for a first tool. Replit's invite-only gate needs the Pro plan. Both MCP servers send prompts to their own builder rather than taking code from your agent, and neither offers a scoped key for an outside agent.
When is Retool the right choice?
When the tool is a dashboard or admin panel over data your company already connects to Retool. Retool's org login, Postgres database, and Workflows cover the basics. Apps live inside Retool's app model, per-app permissions need the Business plan, and an agent's key is a workflow webhook key that you revoke by rotating it.
What about general hosting like Vercel, Railway, Render, Fly.io, and Heroku?
They run the code well, but sign-in and agent keys are yours to build. Vercel's Deployment Protection admits only Vercel accounts, Railway's login gate starts at a $5,000 monthly commitment, and Render and Fly.io have no gate at all. Pairing Vercel with Supabase for sign-in takes about 448 lines of template auth code. We traced that path step by step.
How should you choose?
- You build with Claude Code, Codex, or Cursor: floo.
- Lowest cost, and SQLite is fine: Cloudflare.
- You want a vendor's agent to build it in the browser: Lovable or Replit.
- It's a panel over company data already in Retool: Retool.
Sources
- floo: app auth, app API keys, Postgres, cron jobs, pricing
- Cloudflare: one-time PIN, service tokens, D1, cron triggers, Workers pricing
- Lovable: publish, plans, jobs, MCP server
- Replit: deployments, private deployments, MCP server, pricing
- Retool: sharing, permission groups, Retool Database, pricing
- Base44: managing access, personal access tokens
- Vercel and Supabase: Deployment Protection, protection bypass, Hobby plan, Supabase API keys, with-supabase template
- Bolt: publishing, pricing
- Railway: Railway Authentication, pricing
- Heroku: wwwhisper, pricing
- Fly.io: private apps, Managed Postgres
- Render: authentication guide, pricing
- Firebase: manage users, scheduled functions
- Netlify: Netlify Database, scheduled functions
Frequently asked questions
What is the best platform to host an internal tool built with AI?
If your own agent builds it, such as Claude Code, Codex, or Cursor, floo is the strongest fit: invite-only sign-in, Postgres, scheduled jobs, and a scoped API key per agent come in one app. If you want a vendor's agent to build it in their editor, Lovable or Replit fit. If it is an admin panel over data your team already keeps in Retool, use Retool.
Which platforms give an AI agent its own scoped API key?
Of the 15 platforms compared, only floo and Cloudflare give an outside agent its own key that is limited to one app and revocable without affecting people. floo also adds per-key rate limits and a request log.
Can I host an internal tool for free?
Cloudflare, Retool, Lovable, and Railway have free options. Cloudflare's database is SQLite, Retool's free database pauses after a month idle, Lovable's free invite-only publishing allows up to 10 people per project, and Railway's free plan includes $1 of usage a month but its built-in sign-in needs a $5,000 monthly commitment. floo has no free plan; Pay as you go has no monthly commitment and you buy credits for usage.
Do my teammates need an account to open the app?
On floo, Replit, Lovable, and Vercel, invited people sign in with an account on that platform. Cloudflare Access lets invited emails in with a one-time code.
Can Claude Code deploy an internal tool on these platforms?
On floo, Vercel, Cloudflare, Netlify, Firebase, Railway, Render, Fly.io, and Heroku, your own agent can write and ship the code. Replit's and Lovable's MCP servers send prompts to their own builder agent instead. Bolt has no public API or CLI.