AI agent spend guard

Wake up to an alert, not a $4,000 AI bill.

A looping agent can spend that before the invoice arrives. Set a daily cap and BillCurfew emails you when a key crosses it. The check runs about every five minutes. It does not block the next request, and it is not a proxy.

Start free with one key, no cardSee the two-minute setup

No card for the free tier. Prompts never touch BillCurfew.

No proxy. Requests still go straight to the provider.

No code change. Paste a management key. Leave the SDK alone.

No prompt access. We read usage and dollars, never the conversation.

Lights out, on a schedule you pick

01

Paste the admin key

OpenAI organization admin, Anthropic org admin, or an OpenRouter management key. About two minutes. No SDK, no base URL, no proxy.

02

Set a bedtime

A daily dollar cap per key, and a spike rule: if spend in M minutes jumps past N times the recent baseline, that’s a loop.

03

We knock, or we cut the lights

Email fires on the five-minute poll, on every plan. A manual kill works on Free. Slack and auto-kill are paid-only, and auto-kill stays off until you turn it on. OpenAI deletion is permanent.

The other tools sit in the request. We don’t.

Helicone, Portkey, Requesty, and LiteLLM earn their keep by being the path the prompt takes. That is useful for logs and routing. It is the wrong shape when the only job is “this agent is spending like it forgot to sleep.”

Sees prompts

Gateway / proxy. Yes, that’s the product

BillCurfew. No

Code or base URL change

Gateway / proxy. Required

BillCurfew. None

Stops the next token

Gateway / proxy. Can, because it is in path

BillCurfew. No — we act on the next poll

Kills a key the provider already issued

Gateway / proxy. Usually no

BillCurfew. Manual kill on every plan, including Free. Auto-kill is paid-only.

Setup

Gateway / proxy. SDK, proxy, or virtual key

BillCurfew. Paste an admin key

A free key, or a 14-day trial

Monthly USD. Solo, Team, and Agency each include a 14-day trial. Stay on free if one key, email, and a manual kill are enough.

Free
One key. Email when it stays up past bedtime.

$0/mo

  • 1 provider connection
  • 1 watched key
  • No client grouping
  • Email alerts
  • Manual kill
  • No digest
  • 7 days of history

Not included: Slack, auto-kill, client budgets, digest

Use the free tier
Solo
For indie devs shipping agents on their own keys.

$19/mo

14-day trial, then monthly

  • 3 provider connections
  • 10 watched keys
  • 1 client
  • Email alerts
  • Manual kill
  • Slack webhook
  • Optional auto-kill
  • Morning digest
  • 30 days of history
Start Solo trial
Team
A shared bench of agents, with Slack and auto-kill.

$49/mo

14-day trial, then monthly

  • 3 provider connections
  • 50 watched keys
  • 15 clients
  • Email alerts
  • Manual kill
  • Slack webhook
  • Optional auto-kill
  • Morning digest
  • 90 days of history
Start Team trial
Agency
Per-client budgets across every key you operate.

$149/mo

14-day trial, then monthly

  • 3 provider connections
  • 500 watched keys
  • 1,000 clients
  • Email alerts
  • Manual kill
  • Slack webhook
  • Optional auto-kill
  • Morning digest
  • 365 days of history
Start Agency trial

Questions worth asking before you paste a key

Put the invoice on a curfew.

One provider, one key, email alerts. Upgrade when the roster grows.

Create the free accountStart 14-day Team trial

Team is $49/mo after 14 days. Card asked on the next step, at Stripe.