What Is an IOU Token? | ATXP
An IOU token in ATXP is a prepaid credit that agents use to access tools and services on the platform. New accounts receive 10 starter IOU tokens on registration. Tokens are spent per tool call — image generation, search, LLM inference, storage — with no subscription required.
Why IOU Tokens Exist
The core problem with machine payments is that traditional payment rails were not built for them. Credit card transactions have authorization steps, fraud checks, and minimum viable amounts — none of which work well for a system processing thousands of micropayments per hour.
IOU tokens solve this by moving payment from the transaction layer (where every tool call would require a payment authorization) to the funding layer (where a human adds funds once, and the system tracks spend against that balance).
The model is familiar: think of a subway card, a prepaid mobile phone plan, or a gaming platform’s credits. A human loads value once. The system deducts per use. No authorization step per transaction. No credit card declining on the third image generation call.
For AI agents specifically, the prepaid model has an additional benefit: it bounds spending. An agent can only spend what’s in its balance. A bug, an infinite loop, or unexpected behavior cannot cause unbounded charges.
How IOU Tokens Work
- Account creation: New ATXP accounts receive 10 starter IOU tokens — free, no credit card required. This is enough to run dozens of tool calls and evaluate the platform.
- Tool calls: Each call to an ATXP tool deducts tokens from the balance at the published per-call rate.
- Top-up: When the balance runs low (or before deploying an agent to production), the developer purchases additional tokens.
- Balance monitoring: The ATXP dashboard shows current balance and a complete call log with per-call costs.
- Agent-to-agent: One ATXP agent can transfer tokens to another — enabling payment for subtasks completed by specialized agents.
IOU Token Costs by Tool Category
Token costs reflect underlying infrastructure costs, not markup:
| Tool Category | Approximate Cost | Notes |
|---|---|---|
| Web search | Low | Fast, lightweight |
| LLM inference (small model) | Low–Medium | Scales with context length |
| LLM inference (large model) | Medium–High | Scales with context length |
| Image generation | Medium | Per image |
| Video generation | High | Compute-intensive |
| File storage | Very low | Per operation |
| Code execution | Medium | Per run |
Exact token rates are published on the ATXP platform and updated as underlying costs change. ATXP’s published policy is at-cost passthrough — no margin on tool access.
IOU Tokens vs. Subscriptions
The economic difference is significant for variable-use scenarios:
Subscription model: Pay $20/month for image generation whether you generate 1 image or 500. If your agent has a slow month, you’ve paid for capacity you didn’t use.
IOU token model: Pay exactly for the images you generate. Zero cost in slow months. Linear cost scaling with actual production usage. No idle capacity cost.
For agents with predictable, high-volume usage, subscriptions can sometimes be cheaper. For most agent workloads — especially during development, testing, and variable production — IOU tokens are cheaper and simpler.
Get started: npx atxp — creates an account with 10 free starter IOU tokens.
Frequently Asked Questions
What is an IOU token?
An IOU token is a prepaid credit in the ATXP system that agents use to pay for tool calls. New accounts receive 10 free tokens. Additional tokens are purchased as needed. There are no subscriptions or monthly fees — you pay only for what your agent actually uses.
Do IOU tokens expire?
No. IOU tokens do not expire. An account created today and not used for six months still has its full token balance when you return to it. There are no maintenance fees, no inactivity charges, and no token expiration dates.
Can I get a refund on unused IOU tokens?
ATXP’s refund policy is available in the platform documentation. In general, because tokens are prepaid credits for platform access rather than a subscription, refund terms apply to unused balances per ATXP’s standard terms.