How to Run OpenClaw 24/7 for $6 a Month

Hello builders,

An OpenClaw agent can answer messages and check in on its own all day and all night for about $6 a month, and you can work that number out to the cent before you commit. The bill that catches people is one they never asked for, and a widely shared cost post put it plainly: “One user woke up to an unexpected $141 bill overnight because the heartbeat was hitting the wrong model.” Search openclaw reduce cost multi model routing and every top result sells you a router, yet the product ships no router at all, and four settings you already have do the job.

So where does the money actually go? Mostly into what gets sent again on every turn. Your agent carries a standing context on every request: the system prompt, your SOUL.md and AGENTS.md, the description of every skill it can see, and some history. Call it 8,000 tokens. Thirty messages a day is 900 a month, which is 7.2 million input tokens before we’ve typed anything interesting. Then there’s the heartbeat, a check-in that runs every 30 minutes by default whether we’re using the agent or not. That makes 1,440 calls a month, each one carrying the same 8,000 tokens. Which of those two do you think costs more?

Start with the left half of the picture, because it decides which bill you’re even looking at. If you planned to run the agent off a Claude subscription, programmatic use now draws on Agent SDK credits: a fixed monthly allowance billed at API rates that does not roll over, that you top up at pay-as-you-go prices when it runs out, and that cannot fall back on your normal plan limits. On API credits, the only stop button is the cap you set on the provider’s dashboard, since OpenClaw has no spend limit of its own. Find your route first, then pull the four levers along the bottom.

Four settings, one block

Run this on the machine the agent lives on. Lever 2, prompt caching, has no switch, so we leave it out of the block.

openclaw models set moonshot/kimi-k2.6                    # lever 1: a cheap primary
openclaw models fallbacks add anthropic/claude-haiku-4-5  # only fires if the primary fails
openclaw health                                           # lever 3: find "Heartbeat interval: 30m (main)"
openclaw config set agents.defaults.heartbeat.every 2h    # stretch it if 30 minutes is more than you need
openclaw agents add heavy --workspace ~/oc-heavy --model anthropic/claude-sonnet-5   # lever 4
openclaw agent -m "Review this clause and flag the risks: ..." --agent heavy
openclaw gateway usage-cost --days 30                     # what you actually spent

If models set answers Unknown model provider "moonshot", which it did on a fresh 2026.9.6 test install of mine, run openclaw plugins install @openclaw/moonshot-provider first and try again. On extended-stable 2026.7.35 the provider is already there.

Why does Kimi K2.6 win the everyday work? Its pricing page lists $0.95 per million input tokens, $0.16 on a cache hit and $4.00 for output. Anthropic’s pricing docs put the same idea in one sentence:

A cache hit costs 10% of the standard input price, which means caching pays off after one cache read for the 5-minute duration (1.25x write), or after two cache reads for the 1-hour duration (2x write).

Run the numbers on our 30-message agent. Uncached, the standing context costs $6.84 a month and the heartbeat $10.94, so the check-in nobody asked for is the bigger line. Cached, those drop to $1.15 and $1.84, while new words ($0.43), replies ($1.44) and heartbeat replies ($0.29) stay put. That comes to $19.94 against $5.15, for the same agent doing the same work. Caching works when the front of that context stays the same, so I keep SOUL.md and AGENTS.md settled and prune skills I’ve stopped using.

The heartbeat is where the $141 story comes from. Pointed at Claude Sonnet 5, at $2 per million input tokens, it costs $23.04 a month on its own, and on Claude Opus 5 at $5 it runs $57.60 before we have sent a single message. Moving it from 30 minutes to 2 hours takes our $5.15 down to $3.55. The heartbeat.every line in the block is how I set that on 2026.9.6, where the default is still 30 minutes. On my test gateway openclaw health kept showing 30m until I restarted the gateway, then read Heartbeat interval: 2h (main).

My take on the router question is simple. You always know which model ran, because you chose the agent, and on a bill that predictability is worth more than cleverness. If you genuinely want per-request routing, a plugin or an aggregator will do it, and we’d be adding a part the product doesn’t have.

What is the second agent actually for, then? The contract review, the proposal a client will read, the analysis where reasoning shows up in the result. We send those to heavy by name and let the cheap primary carry everything else, including the heartbeat, which follows the primary unless we point it somewhere else. Then, once a week, openclaw gateway usage-cost --json shows a cacheRead total per day, which tells you whether caching is working on your own machine. It’s also the number you can quote a client for their setup, down to the cent, and almost nobody else walks in with it.

Now go build something this weekend!

John Cook