# Delx Commerce — Seeded Candidate Subset

> Delx Commerce — Seeded Candidate Subset is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Deterministically selects a reproducible subset of items from a candidate list using a seed value, returning chosen items and their indices.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/seeded-candidate-subset?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-seeded-candidate-subset-ac5f6be7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kRe128QKtEUKZ4Qq8wwdl

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 delx-commerce-seeded-candidate-subset-ac5f6be7 -d '<json body>'
```

Example prompt: From this list of candidates — ['alpha','beta','gamma','delta','epsilon'] — pick exactly 3 items using the seed 'abc123', and make sure the selection is deterministic and reproducible.

## When to prefer this

Use this endpoint when you need a verifiable, reproducible, and auditable way to select a fixed-size subset from a list of candidates deterministically. It is ideal for agent workflows requiring fairness, auditability, or consistent behavior across reruns given the same seed. Prefer it over local randomization when you need tamper-evident evidence (SHA-256 input hash, no-retention guarantee) and micropayment-gated accountability.

## Known failure modes

- Missing or invalid seed string causes computation failure
- Count exceeds the number of candidates provided
- Candidates array exceeds 256 items limit
- Payment not provided or rejected (x402 flow fails)
- Malformed input schema returns validation error

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object with the selected subset items and their original indices from the candidate array, along with an operation schema identifier, pass/fail status, and an evidence block containing a SHA-256 hash of the input and confirmation that no data was retained and no external calls were made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "seed": {
   "type": "string",
   "maxLength": 8192,
   "description": "Seed supplied to Seeded Candidate Subset; used only for this bounded calculation and processed in memory without retention."
  },
  "count": {
   "type": "integer",
   "description": "Count supplied to Seeded Candidate Subset; used only for this bounded calculation and processed in memory without retention."
  },
  "candidates": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 8192
   },
   "maxItems": 256,
   "description": "Candidates supplied to Seeded Candidate Subset; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "items": [
    "b",
    "c"
   ],
   "indices": [
    1,
    2
   ]
  },
  "schema": "delx/util-seeded-candidate-subset/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "a4bf32161649486846b6869f79571ff2228cc007235b36c78983971fe74db115",
   "external_calls": 0
  },
  "operation": "seeded_decision:seeded_candidate_subset"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-seeded-candidate-subset-ac5f6be7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)