# Delx Cohort Retention

> Delx Cohort Retention is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Calculates per-cohort and weighted aggregate retention rates from a bounded list of cohort data

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/cohort-retention
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-cohort-retention-6919ef49
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NTJVZvDYI0tgoGonVGSJm

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-cohort-retention-6919ef49 -d '<json body>'
```

Example prompt: Calculate the per-cohort and weighted retention for these cohorts: cohort A has 1000 users with 720 retained, cohort B has 800 users with 560 retained, and cohort C has 500 users with 300 retained.

## When to prefer this

Choose this endpoint when you need a fast, deterministic, stateless cohort retention calculation as a preflight or analysis step in an enterprise agent workflow — especially when data privacy matters since it is local-only with no upstream data retention. Prefer it over general analytics platforms when you need machine-readable JSON output at low cost ($0.003 USDC) without spinning up a full analytics pipeline.

## Known failure modes

- Empty or missing cohorts array returns validation error
- Cohort entries with zero users may cause division-by-zero handling
- Malformed cohort objects with missing required fields return schema errors
- Negative user counts or retained counts exceeding totals may return computation errors
- Request without valid x402 USDC payment on Base results in 402 Payment Required

## How this service works

Calculate per-cohort and weighted retention from bounded cohorts. Use it as a bounded preflight or analysis step inside an enterprise agent workflow before data, policy, integration, security, or commercial decisions reach production. Returns deterministic machine-readable JSON for $0.003 USDC via x402 on Base. Execution is first-party, local-only, stateless, memory-only, and has no paid upstream or input retention. Results are advisory; the caller remains responsible for authorization and prod…

## Output

Returns a deterministic machine-readable JSON object containing per-cohort retention rates for each input cohort and a weighted aggregate retention metric across all cohorts, computed locally without any external calls or data retention.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "cohorts": {
   "type": "array",
   "description": "Input field: cohorts."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "schema": "delx/util-cohort-retention/v1",
  "cohorts": [
   {
    "start": 100,
    "cohort": "2026-07",
    "retained": 42,
    "retention_percent": 42
   }
  ],
  "cohort_count": 1,
  "weighted_retention_percent": 42
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-cohort-retention-6919ef49/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)