Know what your agent will cost before you build it.
Runcap estimates the cost of a coding-agent run as a range, sets a hard ceiling that physically stops the run, compresses wasted tokens out of every call, and hands you the exact rescue prompt when the agent gets stuck. Your code and tokens never touch a server.
You would have spent $18.40. Runcap compressed it to $11.00 and would have killed the run at your $15 cap. Same answers, fewer tokens, no surprise invoice.
Every other tool is a rear-view mirror that shows you the bill after you paid it. Runcap estimates the bill before you start and caps it. It's a circuit breaker, not a dashboard.
The 2am surprise invoice
Multi-agent coding runs burn roughly 15x more tokens than a single chat. Agents loop on the same error, rewrite plans, and hand you a confident summary while the task is not actually done, and you find out what it cost when the invoice, or the subscription limit, arrives. Observability tools measure the past. Gateways route the present. Neither stops the spend before it happens.
See it in 60 seconds
No API key required. Runcap catches a too-broad request before it spends a cent, then hands back a rescue prompt the moment a run gets stuck.
$ runcap preflight -- claude "build the full app with auth, payments, deploy" Scope risk: high Recommendation: Do not launch as one broad mission. Split into one vertical slice with a verification command. $ runcap run --label demo -- npm run build Error [ERR_MODULE_NOT_FOUND]: Cannot find package '@/components' Runcap mission: 20260601T221531-demo Status: stuck (medium confidence) Changed files: 0 Parsed errors: 1 Primary recommendation: Resolve missing import before continuing Rescue prompt: Do not continue broad implementation. Diagnose this missing module first: Cannot find package '@/components'. Check package.json, tsconfig paths, and the latest git diff. Make the smallest change that resolves the import, then run the command again.
The compression no other proxy has
Coding agents read a file, change one line, then re-read it. The two copies are almost identical, so the dedup every other gateway does saves nothing on the second copy. Runcap is the only one that sends a lossless line-diff against the version the model already saw, and the model reconstructs the current file from it. Same answer, a fraction of the tokens.
These are the token counts OpenAI itself billed on two identical calls, not an estimate. The model never received the full re-read, only the diff, and still answered correctly about the one changed line. Lossless by construction: Runcap refuses to emit a delta unless it reconstructs the original byte for byte.
See the proof and reproduce itWho this is for
Runcap is a developer tool. It runs a local gateway that your agent's API calls pass through, so it can price and cap them before they reach the paid provider. To use it you already need three things in place.
Your own API key
An OpenAI or Anthropic key. Runcap never sells or supplies model access, it only caps the spend on the key you already have.
Your own agent
Claude Code, Codex, or any script that calls the OpenAI or Anthropic API. Runcap wraps it, it does not replace it.
Comfort with a CLI
You run one command and a local process on your machine. If you want a no-account web app that runs the AI for you, this is not that.
Install in 30 seconds
# run the demo with zero setup git clone https://github.com/kirder24-code/ai-agent-manager.git cd ai-agent-manager npm run setup npm run demo # or install the CLI globally npm install -g runcap # put a hard daily ceiling on any Claude or OpenAI agent ANTHROPIC_API_KEY=sk-ant-... AIM_DAILY_BUDGET_USD=5 runcap gateway # the run is killed the moment spend crosses your ceiling
The honest claim
Runcap does not promise an exact cost oracle. Agent runs are stochastic and nobody can predict the exact token count. So it gives you a range plus a hard cap: "this build is roughly $3 to $7, cap it at $10." The range is the headline. The hard cap is the product. Every output carries a truth label (observed, calculated, provider_usage, unknown). If Runcap can't prove something, it says so.
Pricing
The local core is free forever and never crippled. Only persistence, collaboration, and aggregation are paid: the things that only matter once data leaves your laptop.
After launch, Runcap moves to standard subscription pricing:
| Tier | Price | What you get |
|---|---|---|
| OSS MIT, local |
$0 forever |
All local runs, cost estimation, hard spend cap, run wrapping, stuck detection, rescue prompts, local dashboard. |
| Pro | $19/mo founders pay $49 once |
Cloud sync across machines, hosted dashboard, estimate-vs-actual trends, shareable reports, alerts on cap breach. |
| Team | $49/seat/mo | Shared budget pools, org-wide ceilings, per-project rollups, role-based caps for junior devs. |