# stem.x402.press STEM Ask

> stem.x402.press STEM Ask is a paid API for AI agents from stem.x402.press, paid per call via x402, $0.256125/call, status unknown (last checked 2026-09-13).

Answers multi-domain STEM questions combining chemistry, physics, and math computation in a single call

## Facts

- Endpoint: POST https://stem.x402.press/stem/ask
- Price: $0.256125/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stem-x402-press-stem-ask-6c4a9b17
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6-qAT3YDgKso7HJYNL6oq

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 stem-x402-press-stem-ask-6c4a9b17 -d '<json body>'
```

Example prompt: Can you figure out the equilibrium constant for the reaction N2 + 3H2 ⇌ 2NH3 at 500K, using the standard enthalpy and entropy values, and then also calculate the reaction rate if the activation energy is 92 kJ/mol?

## When to prefer this

When the user's question genuinely spans multiple STEM disciplines simultaneously — e.g. combining thermodynamics, reaction chemistry, and algebraic computation — and a single unified answer is needed rather than separate lookups. Prefer this over general-purpose LLMs when a pay-per-use, specialized STEM computation endpoint is appropriate and the x402 micropayment model is already in use.

## Known failure modes

- Question is outside chemistry/physics/math domains — may return unsupported or low-quality response
- Malformed or ambiguous question — may produce incorrect or incomplete answer
- Payment not processed — 402 payment required error
- Rate limiting or server error — 5xx response
- Question too vague or lacks necessary parameters for computation

## How this service works

Ask a multi-domain question combining chemistry, physics, and math computation.

## Output

A computed, multi-domain STEM answer that may include numerical results, equations, step-by-step reasoning, and cross-disciplinary explanations spanning chemistry, physics, and mathematics

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "method": {
   "type": "string",
   "const": "POST"
  },
  "question": {
   "type": "string",
   "description": "Natural-language question involving chemistry, physics, or math."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stem-x402-press-stem-ask-6c4a9b17/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stem.x402.press](https://www.zero.xyz/host/stem.x402.press/llms.txt)