# Delx Seeded Reservoir Sample

> Delx Seeded Reservoir Sample is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Performs a reproducible reservoir sampling of an integer array using a seed string, returning a fixed-count random subset with the original indices.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/seeded-reservoir-sample
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-seeded-reservoir-sample-d2a2f9d7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4HOVJ-jgWdqm8c76rqspu

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-reservoir-sample-d2a2f9d7 -d '<json body>'
```

Example prompt: Using the seed 'launch-2024', randomly pick 3 items from this list of integers [1, 2, 3, 4, 5, 6, 7, 8] in a reproducible way — I need to know which items were chosen and their original positions.

## When to prefer this

Choose this endpoint when you need reproducible, auditable random subset selection from an integer list — especially when the same seed must always yield the same sample (e.g. experiments, draws, scheduling). It is preferable to implementing local shuffling when you need tamper-evident proof via input hashing and a guarantee of no data retention or external calls.

## Known failure modes

- Array exceeds 256-item maximum — request rejected
- Count exceeds the number of available items — may return error or partial result
- Malformed seed string (exceeds 8192 chars) — validation error
- Missing required fields (seed, count, or items) — 400-level error
- Non-integer values in items array — schema validation failure

## How this service works

Seeded Reservoir Sample: Seeded Reservoir Sample selects a bounded reproducible sample from caller items from bounded caller-supplied values without an external provider. Call Seeded Reservoir Sample 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 Reservoir Sample as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. Fi…

## Output

Returns a JSON object containing: the sampled integer items, their original indices in the input array, a status of 'pass', the SHA-256 hash of the input for auditability, confirmation that no data was retained, the count of external calls made (always 0), and an operation identifier string.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "items": [
    1,
    3,
    5
   ],
   "indices": [
    0,
    2,
    4
   ]
  },
  "schema": "delx/util-seeded-reservoir-sample/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "fe584420fbe1d387c960f909168094961a1eae04083c9ffe25a052869b8a68e5",
   "external_calls": 0
  },
  "operation": "seeded_decision:seeded_reservoir_sample"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-seeded-reservoir-sample-d2a2f9d7/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)