# Delx Seeded Candidate Subset

> Delx Seeded Candidate Subset is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Deterministically selects a reproducible subset of candidate items from a list using a seed string and a count, returning the selected items and their original indices.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/seeded-candidate-subset
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-seeded-candidate-subset-e9410360
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ae9hQQk1cutWlfrODeS-s

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-seeded-candidate-subset-e9410360 -d '<json body>'
```

Example prompt: Pick 2 items from this list ['a', 'b', 'c', 'd'] using the seed 'myseed42' — I need the same selection every time I run this with the same seed.

## When to prefer this

Choose this endpoint when you need reproducible, auditable, deterministic subset selection from a list — especially in agent workflows where re-running with the same inputs must yield identical results. Prefer it over random sampling when consistency across runs matters, or when you need a lightweight, no-retention computation with an evidence trail (input hash, zero external calls). It is ideal for stable A/B assignments, batch sampling, shortlisting, and any scenario where seeded determinism is required rather than true randomness.

## Known failure modes

- Count exceeds the length of the candidates array — returns an error or empty result
- Candidates array exceeds the 256-item maximum — request rejected
- Seed string exceeds 8192 character limit — request rejected
- Missing required fields (seed, count, or candidates) — validation error
- Non-integer count value — schema validation failure

## How this service works

Seeded Candidate Subset: Seeded Candidate Subset selects a reproducible candidate subset while preserving original order from bounded caller-supplied values without an external provider. Call Seeded Candidate Subset when an agent needs a reproducible decision that another run can independently replay. Returns the deterministic selection plus seed provenance, population bounds, and the operation-specific outcome for Seeded Candidate Subset as versioned deterministic JSON. Price: $0.001 USDC via…

## Output

Returns a JSON object containing the selected subset items as an array, their original indices in the input list, an operation identifier, a status field ('pass'), and an evidence block confirming no data was retained and providing an input hash and external call count — enabling auditability of the deterministic selection.

## 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-seeded-candidate-subset-e9410360/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)