Introducing Arbex AI

Your team says it. Arbex buys it.

Arbex is an AI purchasing copilot built into Sentinel Finance. It researches vendors, navigates their sites, and completes purchases so your team never has to.

Meet Arbex AISee How It Works
Anthropic Computer UseGPT-4o PoweredAny VendorSOC 2 Ready
Arbex purchasing workflows inside Sentinel Finance
HOW ARBEX WORKS

Three words. One purchase.

From request to receipt without touching a browser.

01

Just Ask

Natural Language

Type or say what you need. Arbex extracts vendor, plan, quantity, and budget from plain conversation.

02

Arbex Navigates

Computer Use

Arbex opens the vendor site, logs in with your company credentials, selects the right plan, and checks out.

03

Done. Logged.

Audit Trail

A screenshot of the completed purchase lands in your audit log automatically categorized and filed.

THE OLD WAY

Buying software shouldn't start a Slack thread.

Every tool purchase triggers a chain reaction. Arbex kills it.

01

3-Day Slack Thread

A $12 tool requires manager approval, finance card details, and IT security review. Days wasted, momentum lost.

02

Manual Errors

Wrong plan, wrong seats, wrong billing cycle. No one catches it until the invoice arrives.

03

Zero Visibility

Finance has no idea what's been purchased until month-end. No real-time audit trail.

THE TRUST LAYER

Arbex is powerful. That's exactly why we built Sentinel.

Giving AI access to your company's purchasing power is only acceptable with enterprise-grade controls. Sentinel is that control layer running silently behind every Arbex action.

Arbex executes. Sentinel decides whether it's allowed to.
HOW SENTINEL PROTECTS YOU

Three layers of control. Always on.

P
BEFORE PURCHASE

Policy Gate

Sentinel checks vendor allowlist, remaining budget, category rules, and approval thresholds before Arbex touches anything. ALLOW, BLOCK, or REVIEW.

A
REAL-TIME

Anomaly Detection

Statistical analysis catches sudden spending spikes, unusual hours, and first-time high-value vendors before they become problems.

!
INSTANT

Emergency Kill Switch

Freeze all Arbex activity in one click. Revokes sessions, blocks purchases, and logs every action without touching your payment rails.

Every purchase is logged with screenshots, decision tokens, and policy version. Audit-ready from day one.
ADVANCED CONTROLS

Security features that go beyond basic rules

Sentinel catches threats that simple amount limits miss.

Statistical outlier analysis on every transaction

Anomaly Detection

  • +Flags transactions exceeding 2x from historical mean.
  • +Detects sudden 10x spending spikes per agent.
  • +Catches high-value transactions at unusual hours.
  • +Alerts on first-time vendor and high-amount combinations.
Anomaly Detection
Operator-managed incident response that stops payments in one click

Emergency Kill Switch

  • +Dedicated operator console for customer organization freeze controls.
  • +Global kill switch halts gate evaluation and payment execution instantly.
  • +Per-organization freeze contains incidents without affecting other tenants.
  • +Force logout all sessions and revoke every API key in seconds.
  • +Every activation is captured in the audit trail with a reason tag.
Emergency Kill Switch
Purpose-built controls for irreversible blockchain rails

Crypto and USDC Native

  • +Address allowlists ensure only approved wallets receive funds.
  • +Chain allowlists restrict execution to approved networks.
  • +New addresses auto-escalate to human review.
  • +Per-transaction USDC ceilings remain separate from fiat limits.
Crypto and USDC Native
INTEGRATE IN MINUTES

One API call. Full spend control.

Drop Sentinel into your existing agent workflow with a single HTTP request. No SDK required.

POST /api/agent/evaluate
curl -X POST https://api.sentinelfinancehq.com/api/agent/evaluate \
  -H "Authorization: Bearer sk_live_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "vendor": "AWS",
    "category": "cloud_infra",
    "amount": 2500,
    "currency": "USD",
    "reason": "Monthly compute scaling"
  }'
Response
{
  "request_id": "req_8f3a...",
  "decision": "ALLOW",
  "policy_version": 5,
  "reason": "Policy v5: amount 2500 <= auto_allow 5000",
  "decision_token": "eyJhbGci...",
  "latency_ms": 42
}

Returns ALLOW, BLOCK, or REVIEW in under 100ms. Signed decision tokens for downstream execution proof.

ECOSYSTEM

Works with any AI agent framework, with no vendor lock-in.

LangChainAutoGPTCrewAIOpenAI AgentsVercel AI SDKCustom Agents
PRICING

Simple, transparent pricing

Every paid plan includes a monthly event pool. Overage is metered automatically with no surprises.

For early production teams

Starter

$29/mo
Includes 1,000 events, then $0.050 per event

Base platform fee plus metered overage once you clear the included monthly traffic pool.

  • + 1,000 included events / month
  • + $0.050 per additional event
  • + Hosted Lemon Squeezy checkout
  • + Usage-based billing ready
Start Starter
Most Popular
Recommended for finance ops

Professional

$99/mo
Includes 10,000 events, then $0.020 per event

Higher included volume and lower overage for teams running continuous AI approval flows.

  • + 10,000 included events / month
  • + $0.020 per additional event
  • + Best price-to-volume ratio for growing teams
  • + Priority onboarding support
Choose Professional
For heavy transaction throughput

Business

$299/mo
Includes 100,000 events, then $0.005 per event

Designed for multi-team deployments that need predictable base fees and very low overage.

  • + 100,000 included events / month
  • + $0.005 per additional event
  • + Metered subscription item sync
  • + Operational support for billing reconciliation
Go Business
Custom volume and controls

Enterprise

Custom

Annual terms, custom onboarding, and enterprise controls for regulated environments.

  • + Custom included event pool and pricing
  • + Dedicated onboarding and architecture review
  • + SSO / SAML and private deployment options
  • + Custom MSA, security review, and invoicing
Contact Sales
All plans include full API access, policy engine, and audit logs. Enterprise plans include custom SLAs and dedicated onboarding.
FAQ

Frequently asked questions

What is Arbex?

Arbex is an AI purchasing agent built into Sentinel Finance. It navigates vendor websites using Anthropic's Computer Use API to complete purchases on behalf of your team after Sentinel's policy gate gives the green light.

What if Arbex buys the wrong thing?

Sentinel's policy gate approves the intent before execution. After purchase, a screenshot and audit log entry are automatically created. Any deviation from the approved amount is immediately visible in the audit trail.

Do you replace Ramp, Stripe, or Brex?

No. Sentinel is an orchestration layer between your AI agents and your existing payment rails. It governs the spend intent before money moves.

How long does integration take?

Most teams integrate the evaluation API in under 30 minutes. It is a single REST endpoint with no SDK installation or agent framework changes required.

How is overage billing calculated?

We aggregate gate evaluations, reviews, spend requests, and payment execution events into a monthly total. Overage beyond your plan is metered and billed automatically.

What data do you store?

Policy configurations, gate evaluation results, approval decisions, billing state, and audit logs. We never store payment credentials, private keys, or card numbers.

Can we run in shadow mode first?

Yes. Shadow mode lets you simulate policy against historical traffic before switching enforcement on, with zero risk to live payments.

Do you support crypto and USDC payments?

Yes. Sentinel has native support for USDC rails with address allowlists, chain restrictions, and separate per-transaction limits for irreversible blockchain payments.

GET STARTED

Ready to govern AI spend?

Start a pilot today, or contact our team directly at hello@sentinelfinancehq.com for enterprise deployment and procurement support.

Request Pilot
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