# Delx Seeded Permutation Index

> Delx Seeded Permutation Index is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-20).

Given a seed string and a count, deterministically computes a permutation index value using a seeded algorithm — no external calls, no data retention.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/seeded-permutation-index?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-seeded-permutation-index-031c31ab
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_T0wgZhkmBE6OGFGLnRWFp

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-permutation-index-031c31ab -d '<json body>'
```

Example prompt: Using seed 'campaign-42' and a permutation count of 500, give me the deterministic permutation index so I can consistently assign this user to a bucket.

## When to prefer this

Choose this endpoint when you need a deterministic, reproducible integer index derived from a seed string and a count — ideal for stable bucketing, A/B assignment, seeded shuffle selection, or any agent workflow requiring consistent permutation results without external randomness sources. Prefer it over local PRNG implementations when auditability (via SHA-256 evidence) and in-memory-only processing guarantees matter.

## Known failure modes

- Missing or empty seed string causes validation error
- permutation_count of zero or negative integer may produce an error or undefined result
- Seed exceeding 8192 characters will be rejected
- Malformed JSON body returns 400 Bad Request
- Payment not provided or insufficient USDC results in 402 Payment Required

## How this service works

Seeded Permutation Index: Seeded Permutation Index selects one reproducible permutation index within a caller count from bounded caller-supplied values without an external provider. Call Seeded Permutation Index 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 Permutation Index as versioned deterministic JSON. Price: $0.001 USDC via x40…

## Output

Returns a JSON object containing a numeric permutation_index derived from the seed and count, the operation name, a SHA-256 hash of the input for auditability, confirmation that no data was retained and no external calls were made, and a pass/fail status.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "seed": {
   "type": "string",
   "maxLength": 8192,
   "description": "Seed supplied to Seeded Permutation Index; used only for this bounded calculation and processed in memory without retention."
  },
  "permutation_count": {
   "type": "integer",
   "description": "Permutation Count supplied to Seeded Permutation Index; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "cryptographic": false,
   "permutation_index": 630
  },
  "schema": "delx/util-seeded-permutation-index/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "937802095c874e8dbf650e4af5cd07ddb5c7691d8eb727c6466e648e0050b056",
   "external_calls": 0
  },
  "operation": "seeded_decision:seeded_permutation_index"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-seeded-permutation-index-031c31ab/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)