# M2M Trust Process Capability Analysis (Cp/Cpk/Ppk)

> M2M Trust Process Capability Analysis (Cp/Cpk/Ppk) is a paid API for AI agents from energybilltoolkit.co.uk, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Computes Cp, Cpk, and Ppk-style process capability indices for a supplied set of numeric sample data against specification limits.

## Facts

- Endpoint: POST https://energybilltoolkit.co.uk/m2m-trust/api/tools/process-capability
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/energybilltoolkit-co-uk-8b7432e1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_O11I7lXMLP6eGqUlUBYfl

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 energybilltoolkit-co-uk-8b7432e1 -d '<json body>'
```

Example prompt: Run a Cp/Cpk/Ppk capability analysis on these 30 measurements: [12.1, 12.4, 11.9, ...] with a lower spec limit of 11.5 and an upper spec limit of 13.0 — I need to know if this process is capable.

## When to prefer this

Use this endpoint when you need deterministic, reproducible Cp/Cpk/Ppk-style process capability indices computed from raw numeric sample data against defined specification limits — particularly in quality engineering, Six Sigma, or SPC workflows where auditability and consistency matter. Prefer this over probabilistic or ML-based tools when exact mathematical repeatability is required.

## Known failure modes

- Insufficient sample size returns an error or unreliable indices
- Missing or invalid specification limits cause computation failure
- Non-numeric values in sample data trigger a validation error
- Lower spec limit greater than or equal to upper spec limit causes rejection
- Empty data array returns an error response

## How this service works

M2M Trust deterministic analysis tool: Cp/Cpk/Ppk-style capability analysis for numeric sample data.

## Output

Returns deterministic Cp, Cpk, and Ppk capability indices along with supporting statistics such as mean, standard deviation, and sigma level, indicating whether the process is capable relative to the supplied specification limits.

## Example request

```json
{
 "input": {
  "body": {
   "context": "Manufacturing process quality control",
   "samples": [
    12.1,
    12.4,
    11.9,
    12.3,
    12,
    11.8,
    12.2,
    12.5,
    11.7,
    12.1,
    12.4,
    11.9,
    12.3,
    12,
    11.8,
    12.2,
    12.5,
    11.7,
    12.1,
    12.4,
    11.9,
    12.3,
    12,
    11.8,
    12.2,
    12.5,
    11.7,
    12.1,
    12.4,
    11.9
   ],
   "lower_spec_limit": 11.5,
   "upper_spec_limit": 13
  },
  "type": "http",
  "method": "POST",
  "bodyType": "json"
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "context": {
   "type": "string",
   "description": "Short domain context for interpretation."
  },
  "samples": {
   "type": "array",
   "items": {
    "type": "number"
   },
   "minItems": 2,
   "description": "Numeric process samples."
  },
  "subgroup_size": {
   "type": [
    "integer",
    "null"
   ],
   "minimum": 2,
   "description": "Optional subgroup size for within-subgroup variation."
  },
  "lower_spec_limit": {
   "type": "number",
   "description": "Lower specification limit."
  },
  "upper_spec_limit": {
   "type": "number",
   "description": "Upper specification limit."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/energybilltoolkit-co-uk-8b7432e1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from energybilltoolkit.co.uk](https://www.zero.xyz/host/energybilltoolkit.co.uk/llms.txt)