Detect infinite loops and redundant calls
Identify the specific failure patterns that turn routine tasks into massive billing spikes.
For AI agents
Real-Time Cost Guardrails for LLM Apps
Stuck loops and retries drain budgets unnoticed. Detect and halt runaway agents mid-execution before the invoice lands.
works with
Your LLM apps
also
Claude Code · beta
starts
Free · offline
terminal·tool_loop
The problem
Token waste shows up late.
If you run AI agents, uncontrolled spend is a surprise no one wants twice.
Agents get stuck—and the meter keeps running
Runaway agents can silently burn thousands overnight. Too often, your first alert is a message from Finance.
Observability is purely reactive
Dashboards are great for post-mortems but they fail to stop an agent actively burning tokens in real time.
Hard to see which agent is the problem
When many agents share spend, one runaway job is easy to miss until the invoice lands.
What you get
Stop paying for noise. Keep shipping agents.
See confidence and approximate cost
Each signal says how sure we are and roughly what it burned.
Built to complement your tracing
TokenSentinel wraps your model client to handle the active interventions your observability dashboards cannot.
Zero data egress
The tool runs entirely in-process so your API keys, prompts, and payload data never leave your infrastructure.
Get started
Three steps in your app.
Watch first. React when waste shows up.
01
Install
Add the Python package.
$pip install token-sentinel[anthropic]
Also: openai, gemini, bedrock, all
02
Wrap your client
One line around the SDK you already use.
agent.py
pythonfrom token_sentinel import Sentinel
import anthropic
sentinel = Sentinel(project="my-agent", mode="log")
client = sentinel.wrap(anthropic.Anthropic())03
Implement active circuit breakers
Use a simple callback to trigger programmatic guardrails the moment costs spike.
agent.py
python@sentinel.on_waste
def handle(event):
print(f"Waste: {event.type}")Enterprise & Teams
Running many agents in production?
Let's talk about scaling your agent infrastructure safely. Tell us how agents operate in your stack and where your current observability blind spots are.
Enterprise & Teams15-Min Founder Session
Book a 1-on-1 demo with our engineering team.
Schedule a 15-minute 1-on-1 walkthrough with our founder about your agent stack and where spend is leaking.