Monitor cloud spending, auto-kill runaway services, protect your infrastructure.
Born from a $91,316 Cloudflare Durable Objects bill. Cloudflare has no spending cap. Neither does GCP. Neither does AWS. This is your safety net.
Website: kill-switch.net | Dashboard: app.kill-switch.net | CLI: npm i -g @kill-switch/cli
# Install the CLI
npm install -g @kill-switch/cli
# Authenticate (opens browser to create API key)
ks auth setup
# Connect your cloud provider
ks onboard --provider cloudflare \
--account-id YOUR_ACCOUNT_ID \
--token YOUR_API_TOKEN \
--name "Production" \
--shields cost-runaway,ddos
# Run a monitoring check
ks checkCloud bills aren't the only runaway anymore. A coding agent (Claude Code, Cursor, Aider) runs a reasoning loop that re-sends its entire accumulated context on every tool call, so LLM spend compounds silently — the failure mode behind the $4,200-weekend, $87k-month, and reported $500M-month "after failing to put usage limits on Claude licenses" stories.
agent-guard caps that loop with two surfaces sharing one
budget (per-session and daily-rolling, each with a soft warn + hard block):
# Through the main CLI:
ks guard install # wire the Claude Code hook
ks guard config --session-hard 30 --daily-hard 150
ks guard status # spend vs budget
# …or the standalone binary, for any agent:
npm i -g @kill-switch/agent-guard
agent-guard proxy # ANTHROPIC_BASE_URL/OPENAI_BASE_URL → hard 402 wall at the cap- Hook (Claude Code) — reads the live transcript, prices real token usage, warns at the soft cap, denies the next tool call at the hard cap. Fails open on any error, so a buggy guard never bricks your session.
- Proxy (any agent) — a local metering reverse-proxy that returns HTTP 402 at the cap. The API literally stops answering — a wall the agent can't argue past.
This works against any coding agent by design: the hook is the friendly native
stop for Claude Code; the proxy is the dumb hard backstop for everything else
(Cursor, Aider, raw scripts). An escape hatch (ks guard pause, or
touch ~/.kill-switch/agent-guard/PAUSED) always belongs to the human, never the agent.
| Provider | Services Monitored | Kill Actions |
|---|---|---|
| Cloudflare | Workers, Durable Objects, R2, D1, Queues, Stream, Zones | Disconnect routes, delete workers, pause zones |
| Google Cloud | Cloud Run, Compute Engine, GKE, BigQuery, Cloud Functions, Cloud Storage | Scale down, stop instances, set quotas, disable billing |
| AWS | EC2, Lambda, RDS, ECS, EKS, S3, SageMaker, Cost Explorer | Stop/terminate instances, throttle Lambda, deny S3 policies |
| RunPod | GPU Pods (on-demand & spot), Serverless Endpoints, Network Volumes | Stop/terminate pods, scale endpoints |
| Redis | Redis Cloud, AWS ElastiCache, Self-hosted (memory, connections, ops/sec) | Kill connections, scale down, flush, pause cluster |
| MongoDB | Atlas clusters, Self-hosted (storage, connections, ops/sec) | Kill connections, isolate (IP whitelist), pause/scale cluster |
| OpenAI | GPT API token usage, request counts, daily cost | Rotate credentials |
| Anthropic | Claude API token usage, daily cost | Rotate credentials |
| xAI (Grok) | Grok API token usage, daily cost | Rotate credentials |
| Replicate | GPU predictions, model usage, daily cost | Rotate credentials |
| Snowflake | Warehouse credits, query costs, data scanning | Scale down warehouse, suspend warehouse |
| Vercel | Function invocations, bandwidth, build minutes | Scale down, disable service |
| Datadog | Host count, log ingestion, custom metrics | Rotate credentials, mute monitors |
| Neon | Compute hours, storage, data transfer costs | Scale down, pause project |
| Neo4j Aura | Graph DB instances, memory, storage, instance count | Pause instance, scale down, delete |
| Package | Description | Deployment |
|---|---|---|
packages/cli |
CLI (ks / kill-switch) — onboard, monitor, kill from the terminal |
npm: @kill-switch/cli |
packages/agent-guard |
Kill Switch for coding agents (agent-guard / ksg, also ks guard) — hook + token-metering proxy that cap per-session & daily LLM spend |
npm: @kill-switch/agent-guard |
packages/api |
Kill Switch API — monitoring engine, rule engine, billing | GCP Cloud Run |
packages/web |
Dashboard — React SPA with Clerk auth | Cloudflare Workers |
packages/kill-switch-cf |
Cloudflare Kill Switch — self-hosted cron Worker | Cloudflare Workers |
packages/kill-switch-gcp |
GCP Kill Switch — Cloud Function triggered by budget alerts | GCP Cloud Functions |
packages/kill-switch-aws |
AWS Kill Switch — Lambda triggered by Budget alerts via SNS | AWS Lambda |
packages/agent |
Edge Agent — deploys to customer's CF account, reports to API | Customer's Cloudflare |
site |
Marketing landing page | Cloudflare Workers |
┌──────────────────────────────────────────────────────────────────┐
│ Kill Switch │
├──────────────────────────────────────────────────────────────────┤
│ │
│ CLI (ks) ──→ Kill Switch API (Cloud Run) │
│ Dashboard ──→ ├── Monitoring Engine (5-min cron) │
│ ├── Rule Engine (programmable) │
│ ├── Alerting (PD/Slack/Discord/Email/GitHub AI) │
│ ├── API Key Management │
│ ├── Forensic Snapshots │
│ └── Stripe Billing │
│ │
│ Model A: Managed Model B: Edge Agent │
│ (we hold credentials) (customer holds credentials) │
│ API ──→ CF/GCP/AWS APIs Agent ──→ CF/GCP APIs locally │
│ Agent ──→ Reports to API │
│ │
│ Kill Switches (self-hosted, open source) │
│ ├── CF Worker (cron, GraphQL, auto-disconnect) │
│ ├── GCP Cloud Function (budget alerts, multi-service shutdown) │
│ └── AWS Lambda (budget alerts via SNS, EC2/Lambda/ECS kill) │
│ │
│ Agent Guard (coding-agent LLM spend, runs on the dev's box) │
│ ├── Hook (Claude Code: transcript-priced, warn→deny tool use) │
│ ├── Proxy (any agent: meters responses, HTTP 402 at the cap) │
│ └── Reports trips ──→ API /agent-guard/events ──→ alerts + UI │
│ │
└──────────────────────────────────────────────────────────────────┘
ks shield cost-runaway # Kill services exceeding daily cost limit
ks shield ddos # Kill services getting excessive requests
ks shield gpu-runaway # Stop unexpected GPU instances
ks shield lambda-loop # Throttle recursive Lambda invocations
ks shield aws-cost-runaway # Emergency stop on AWS daily spend spike
ks shield brute-force # Rotate creds on mass auth failures
ks shield exfiltration # Isolate on unusual egress
ks shield error-storm # Scale down on sustained high error ratecd packages/api
npm test # 587 unit + e2e tests (API), 42 (CLI), 47 (SDK)
SMOKE=1 npm test -- tests/smoke/live-api.test.ts # 12 live API testsThe CLI is designed for AI coding agents (Claude Code, Cursor, Windsurf) to set up monitoring on behalf of users:
export KILL_SWITCH_API_KEY=ks_live_your_key
ks onboard --provider cloudflare --account-id ID --token TOKEN \
--shields cost-runaway,ddos --alert-pagerduty ROUTING_KEY --json
ks status --json # dashboard: accounts, alerts, 30-day spend
ks check --json # violations with multiplier column (e.g. 60x)
ks alerts add --type slack --webhook-url URL --json
ks analytics --json # spend summary + 7-day table + per-accountSee CLI docs for the full reference.
MIT — Use it, fork it, protect your wallet.