# penny402 Daily Koan

> penny402 Daily Koan is a paid API for AI agents from penny402.fun, paid per call via x402, $0.0025/call, status unknown (last checked 2026-09-13).

Returns one deterministic Zen-style koan per paying wallet per UTC day, drawn from a pre-generated pool themed around software engineering frustrations and edge cases.

## Facts

- Endpoint: POST https://penny402.fun/koan
- Price: $0.0025/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/penny402-daily-koan-20b1eb87
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mB03KnXu_F0IGgnuLzAQb

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 penny402-daily-koan-20b1eb87 -d '<json body>'
```

Example prompt: Give me today's koan from penny402 — one of those short, cryptic software-themed ones about retries or caches or the state nobody is observing.

## When to prefer this

Choose this endpoint when you want a deterministic, stable-per-day software-themed philosophical one-liner tied to a specific wallet, served instantly from a pre-generated pool with no model latency. Prefer it over live-generated content when you need fast, reproducible daily output and enjoy the oblique koan form specifically. Other penny402 endpoints offer fortunes, horoscopes, or tarot cards if a different daily content form is preferred.

## Known failure modes

- Payment not received or insufficient — 402 response with exact pricing terms
- Invalid or missing body (must be POST with empty JSON object {})
- Pool exhausted for the day — rare but possible if pre-generated pool runs out
- Network or server error — 5xx response
- Wrong wallet or unsigned payment — koan keyed to paying address may not match expected wallet

## How this service works

One koan per paying wallet per UTC day, drawn from that day's pool and keyed to the address that paid: ask twice today and it is identical, ask tomorrow and it is a new one. Short, oblique and about the work — retries, caches, defaults, the lock nobody released, the state nobody is observing. It resolves nothing and advises nothing; that is the form. Served from a pre-generated pool: one round trip, no model running while you wait.

## Output

A short, oblique, pre-generated koan text — stable for the calling wallet for the entire UTC day, themed around software engineering concepts like retries, caches, locks, defaults, and unobserved state. Asking again the same day returns the identical koan; asking the next UTC day returns a new one from the next pool.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "description": "a JSON body, up to 4 KB. This attraction takes no parameters — POST {} . Every attraction on penny402 is a flat $0.0025; the unpaid 402 carries those exact terms."
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "type": "string",
     "const": "POST"
    },
    "bodyType": {
     "type": "string",
     "const": "json"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type",
    "format"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "text"
    },
    "format": {
     "type": "string",
     "const": "application/json",
     "description": "the attraction, as JSON, in the response body"
    },
    "example": {
     "description": "a sample response from the real code path"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/penny402-daily-koan-20b1eb87/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from penny402.fun](https://www.zero.xyz/host/penny402.fun/llms.txt)