Helicone tracks tokens. Stax tracks your entire AI bill.
Helicone, Langfuse, and Portkey are observability tools built for engineers. They watch the API call. Stax watches the invoice — API spend (OpenAI, Anthropic, Google AI, Mistral) and subscription spend (Cursor, Copilot, ChatGPT Business, Perplexity) — at flat pricing that doesn't climb when your spend does. Four vendors expose admin APIs we sync nightly (OpenAI, Anthropic, Cursor, Copilot). The other four still need a 30-second monthly invoice upload — we'll flip them to live syncs the day those vendors ship admin APIs.
Stax vs Helicone, Langfuse, Portkey.
| Feature | SStax $49/mo flat | SStax Team $99/mo flat | HHelicone maintenance mode | LLangfuse usage + seats | PPortkey usage + seats |
|---|---|---|---|---|---|
| Pricing modelhow the bill is calculated | Flat $49/mo · unlimited providers, unlimited spend tracked | Flat $99/mo · same unlimited model, up to 25 seats | Per-event pricing above 10K req/mo free tier · maintenance mode since Mar 2026 | $29/mo base + $8 per 100K units overage | $49/mo + $9 per 100K requests overage · acquired Apr 2026 |
| Tracks API spendOpenAI, Anthropic, Google AI, Mistral | ✓Yes— OpenAI + Anthropic live; Google AI & Mistral via monthly invoice upload | ✓Yes— same coverage as Stax | ✓Yes | ✓Yes | ✓Yes |
| Tracks subscription toolsCursor, Copilot, ChatGPT Business, Perplexity | ✓Yes— Cursor + Copilot live; ChatGPT Business & Perplexity via monthly invoice upload | ✓Yes— same coverage as Stax | —No | —No | —No |
| Flat pricingcost doesn't rise with usage | ✓Yes— $49/mo regardless of scale | ✓Yes— $99/mo regardless of scale | —No | —No | —No |
| Team member managementinvite teammates, control access | —Single user | ✓Yes— workspace invites, up to 25 seats | ~?— plan-dependent; verify on vendor site | ~?— plan-dependent; verify on vendor site | ~?— plan-dependent; verify on vendor site |
| Billing alertsnotify when spend crosses a threshold | ✓Yes— Slack & email, configurable threshold | ✓Yes— same alerts, shared across workspace members | ~?— verify on vendor site | ~?— verify on vendor site | ~?— verify on vendor site |
| Target audiencewho the UX is built for | Founders, CTOs, CFOs — finance-first views, plain English | Finance stakeholders across the team — same view, shared access | Engineers — prompt traces, latency, eval flows | Engineers — observability, evals, datasets | Engineers — gateway routing, request logs |
| Setup timepaste keys to first chart | 4 minutes · billing-key paste, no SDK | 4 minutes · same setup, then invite teammates | SDK install · proxy or middleware | SDK install · code instrumentation | Gateway re-routing of API traffic |
| Self-serve dashboardsign up, see real numbers same day | ✓Yes | ✓Yes | ✓Yes | ✓Yes | ✓Yes |
| Receipt-grade exportsPDF / CSV finance can hand the accountant | ✓Yes— per-tag, per-team, monthly | ✓Yes— per-tag, per-team, monthly | ~CSV of events | ~CSV of traces | ~CSV of logs |
Stax or Stax Team — how to choose.
Solo founder or a 2–3 person team where one person owns the finances. You need the full picture of your AI bill; you don't need to share access with a CFO or department head yet.
- One workspace, one user
- API spend + subscription spend in one view
- Nightly syncs for OpenAI, Anthropic, Cursor, Copilot
- Monthly invoice upload for everything else
- Billing alerts — set a threshold, get notified
- CSV / PDF exports
- Save $98/yr on annual billing
5+ people, multiple stakeholders who need visibility — your CTO sets up the integrations, your CFO checks the dashboard, a department head watches their team's line. One workspace, everyone sees the same numbers.
- Up to 25 seats, workspace invites
- Everything in Stax, shared across the team
- Member management — add or remove access
- Same flat pricing — $99 is the number, not "starts at $99"
- Save $198/yr on annual billing
Three things every competitor misses.
API-only is half the bill.
The average AI-forward team spends as much on Cursor seats, Copilot seats, and ChatGPT Business seats as it does on raw API tokens — often more. Observability tools watch the token meter and miss the subscription line entirely. If you only see half the bill, you can't make a budget. Stax pulls both in the same view.
Engineer UX, finance question.
Helicone, Langfuse, and Portkey are well-built — for the engineer debugging a prompt. The person who has to answer "why is the AI line $7,400 this month?" is rarely that engineer. Stax is built for the founder, CTO, or CFO who needs the answer in dollars, by team, by month, without learning a tracing tool.
Variable pricing punishes growth.
Usage-based pricing on a cost-tracking tool is the worst possible incentive. The month your AI bill doubles is the month your cost-tracker bill also goes up. Stax is flat $49/mo, regardless of providers connected or dollars tracked. Cost control software shouldn't get more expensive the moment you need it most.
What it costs to track $5,000/mo of AI spend.
A hypothetical mid-stage team: ~$5K/mo across OpenAI + Anthropic API and a half-dozen Cursor + Copilot seats. Roughly 2M API requests, ~50K traced events.
Heads up · these are estimates Competitor figures below are extrapolated from each vendor's public pricing tables — we have not negotiated, audited, or scraped their billing systems. Pricing changes; verify on the vendor's site before you sign anything. The dollar amounts are directional. The point is the shape: every competitor scales with your spend; Stax doesn't.
| Tool | Pricing basis | What's covered | Monthly cost | vs Stax |
|---|---|---|---|---|
| SStax | Flat $49/mo | API providers + subscriptions, unlimited spend tracked | $49 | flat |
| SStax Team | Flat $99/mo | API + subscriptions, up to 25 seats, billing alerts | $99 | flat |
| HHelicone · Pro | $20 base + per-event above 10K reqest. · in maintenance mode since Mar 2026 | API only · no subscription tracking | ~$200 | +$151 |
| LLangfuse · Core | $29/mo + $8 per 100K units above 100Kest. | API only · trace-grade depth | ~$181 | +$132 |
| PPortkey · Production | $49/mo + $9 per 100K requests above 100Kest. · acquired by Palo Alto Networks Apr 2026 | API only · gateway routing included | ~$220 | +$171 |
See the full AI bill — in four minutes.
Paste your billing keys, watch API spend and subscription spend stitch into one view. Flat $49/mo for solo use, flat $99/mo for teams — no per-event metering, no per-seat creep.