# Predge Signed Prediction Commit

> Predge Signed Prediction Commit is a paid API for AI agents from x402-api-production-266e.up.railway.app, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-14).

Commits a tamper-evident, ed25519-signed yes/no prediction on an open Polymarket market, chain-linked and content-addressed for cryptographic integrity.

## Facts

- Endpoint: POST https://x402-api-production-266e.up.railway.app/v1/calls
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/predge-signed-prediction-commit-7fd1a674
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_d8HrvYoimGzChq7gqN-E3

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 predge-signed-prediction-commit-7fd1a674 -d '<json body>'
```

Example prompt: Commit a signed prediction on Polymarket market condition 0xabc123... — I'm calling YES with a $50 stake and note 'strong whale signal on this one'.

## When to prefer this

Choose this endpoint when you need a cryptographically verifiable, tamper-evident record that a prediction was made BEFORE a Polymarket market resolves — not just for storing data, but for producing a chain-linked, ed25519-signed attestation that can be independently verified. Prefer this over generic logging when accountability, non-repudiation, and timestamped forecasting credibility matter.

## Known failure modes

- Market already resolved or closed — endpoint refuses and returns an error indicating the market is not open
- Invalid or unknown condition_id — returns error if the Polymarket market cannot be found
- Malformed side value — must be exactly 'yes' or 'no'
- size_usd with more than 2 decimal places — rejected as it must be a fixed 2-decimal string
- Payment failure — x402 payment of $0.1 USDC not received or invalid
- Note exceeding 500 characters — rejected with validation error

## How this service works

Commit a SIGNED live call: an ed25519-signed prediction (yes/no) on an OPEN Polymarket market, chain-linked (prev_hash) and content-addressed (sha256). Refuses resolved/closed markets — the signature must precede the outcome. Tamper-evident by construction; verify free at GET /verify. Body: {condition_id, side: yes|no, size_usd?, note?}.

## Output

Returns a signed prediction envelope containing the ed25519 signature, sha256 content address, chain-linking prev_hash, the submitted condition_id, side, optional size and note, and a verification reference URL. The record is immutable and can be verified for free at GET /verify.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "note": {
   "type": "string",
   "description": "Optional free-text note (<=500 chars, signed)"
  },
  "side": {
   "type": "string",
   "description": "\"yes\" or \"no\""
  },
  "size_usd": {
   "type": "number",
   "description": "Optional stake to record (signed as fixed 2-dp string)"
  },
  "condition_id": {
   "type": "string",
   "description": "Polymarket condition id of an OPEN market"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/predge-signed-prediction-commit-7fd1a674/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-api-production-266e.up.railway.app](https://www.zero.xyz/host/x402-api-production-266e.up.railway.app/llms.txt)