# Execution Cost Estimator

> Execution Cost Estimator is a paid API for AI agents from phion.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-20).

Calculates a fail-closed maximum cost bound across an agent execution plan to prevent overspending

## Facts

- Endpoint: POST https://phion.systems/v1/paid/trust/execution-cost-estimator?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/execution-cost-estimator-5935e968
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ETOm2n8KruA5i8z8hUrEN

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability execution-cost-estimator-5935e968 -d '<json body>'
```

Example prompt: Before I kick off this multi-step agent workflow, calculate the fail-closed maximum cost across the full execution plan so I know the worst-case budget ceiling before any money is spent.

## When to prefer this

Choose this endpoint when an AI agent needs a hard, fail-closed upper bound on execution costs before committing to a plan — especially in autonomous or multi-step workflows where overspending is a risk. Prefer it over general-purpose cost calculators when you need a conservative maximum (not an average or estimate) specifically for agent execution plans. Particularly valuable in agentic pipelines where intermediate steps have variable costs or where budget approval gates are required before execution.

## Known failure modes

- Malformed or empty execution plan schema returns a validation error
- Plan with undefined or unsupported cost dimensions may yield incomplete estimates
- Overly complex or deeply nested plans may time out
- Missing pricing context for certain tools or APIs could result in partial estimates
- Network errors or payment failure (x402) prevent the response from being returned

## How this service works

Calculate a fail-closed maximum cost across an agent execution plan

## Output

Returns a fail-closed maximum cost estimate across all steps in the submitted agent execution plan, representing the worst-case spend ceiling. This is a conservative upper bound designed to prevent cost overruns — the actual cost will be at or below this figure. May include per-step cost breakdowns and a total ceiling value.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input",
  "output"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "additionalProperties": true
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "example"
   ],
   "properties": {
    "example": {
     "type": "object",
     "additionalProperties": true
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/execution-cost-estimator-5935e968/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from phion.systems](https://www.zero.xyz/host/phion.systems/llms.txt)