Stackon
observability · governance

Know what every run costs — and cap it before it surprises you.

Every span carries a price. Cost rolls those prices up by feature, by model, and by day — then a hard monthly budget refuses any run that would push you past your limit. No end-of-month invoice you didn't see coming.

cost · this month84% of budget

$842 / $1,000

near cap
84% spentsoft @ $750

by feature

canvas$184
evals$93
agent runner$28
adversary$7
last 30 days$842 total
Hard budgets that refuse runsSpend by feature, model, and dayBreach fires a webhook + mobile push

01

Budgets with teeth, not just alerts

Set a soft limit for an early warning and a hard limit that actually stops spend. Once the month's total reaches the hard cap, the next run is refused with a clear error instead of quietly running up the bill. The same check guards the dashboard and the public API, so a runaway script can't out-spend your laptop.

cost · this month84% of budget

$842 / $1,000

near cap
84% spentsoft @ $750

by feature

canvas$184
evals$93
agent runner$28
adversary$7
last 30 days$842 total

02

Spend you can attribute to the dollar

Cost is the sum of every trace and eval run, priced span by span. Break this month down by feature — Agent runner, Canvas, API, Evals — and by the exact model that did the work, then see your most expensive traces ranked with a link straight into the viewer. You always know where the dollars went.

trace · run_8c4fok · 742ms · $0.0053
agent.plan742ms
tools.search_code86ms
llm.complete_refactor612ms
tools.edit_file78ms
evals.no_regression54ms
agentllmtooleval5 spans · 3,007 tok

03

A 30-day trend, zero-filled

A continuous 30-day sparkline shows this-month versus last-month spend and your average per active day, so a slow creep is obvious long before it becomes a number you have to explain. Quiet days read as zero, not gaps — the line never lies about a lull.

cost · this month84% of budget

$842 / $1,000

near cap
84% spentsoft @ $750

by feature

canvas$184
evals$93
agent runner$28
adversary$7
last 30 days$842 total

04

Breaches notify the people who care

When a team crosses its hard cap, Cost emits a signed budget.breached webhook and a mobile push — wire it to Slack, Discord, PagerDuty, or your own infra. Every budget change is written to the compliance audit log, so the trail of who raised the limit and when is always there.

compliance · trust layeraudit-ready
agent.coderAgent run· trace · 8c4f21a12:04:11
u · danaRole changed· member · owner12:04:42
proxyPII redacted· 3 replacements12:05:09
u · renBYOK key rotated· anthropic12:06:30
pii proxy · standardscrubbing

in email dana@acme.io, card 4242 4242 4242 4242

out email <REDACTED:email>, card <REDACTED:credit_card>

anthropic…aF3kopenai…9Qx2
AES-256-GCM

UI + public API

Enforced at

webhook + push

Breach signal

feature · model · day

Attribution

Speed plus trust — prove your agents got better this week.

Cost is one piece of Stackon, the observability-first workspace for teams running Claude and Codex. Start free and instrument your first run today.