# Erlang B & C Staffing Calculator

> Erlang B & C Staffing Calculator is a paid API for AI agents from data-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates the number of trunks (Erlang B) or agents (Erlang C) needed to meet a blocking probability target or service level objective given offered traffic load in erlangs.

## Facts

- Endpoint: GET https://data-calc.x402tookit.com/erlang-staffing?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erlang-b-c-staffing-calculator-25aeccc0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rq4eLw3FophVRW2-GPV1I

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 erlang-b-c-staffing-calculator-25aeccc0
```

Example prompt: I need to know how many agents are required to handle 8 erlangs of call traffic and hit an 80% answered-in-20-seconds service level, with an average handle time of 3 minutes — use Erlang C mode.

## When to prefer this

Use this endpoint when you need classic Erlang B or C staffing/trunking calculations for telephony or call-center capacity planning. Prefer it over generic queueing endpoints (M/M/c) when you specifically need the telecom-standard blocking or service-level formulas with a neighbour sensitivity table. Choose Erlang B mode for circuit-switched trunks with no queuing; Erlang C mode for agent staffing where calls queue.

## Known failure modes

- Missing required trafficErlangs parameter returns validation error
- Extremely high traffic load with no feasible agent count may return degraded/infeasible result
- Invalid mode string (not 'b' or 'c') may default or error
- serviceLevel outside (0,1) or negative handlingSeconds returns bad-request
- Network timeout or upstream service unavailable

## How this service works

Erlang B and C: trunks for a blocking target, or agents for a service level such as 80 percent answered in 20 seconds.

## Output

Returns the recommended number of trunks or agents needed, the achieved blocking probability or service level, occupancy/utilisation, a summary verdict, and a neighbour table showing metrics for ±N trunks/agents around the optimal solution.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "trafficErlangs"
     ],
     "properties": {
      "mode": {
       "type": "string",
       "description": "c (default): agents for a service level, queueing allowed. b: trunks for a blocking target, no queue"
      },
      "serviceLevel": {
       "type": "number",
       "description": "Mode c: fraction answered within answerSeconds, e.g. 0.8 (default 0.8)"
      },
      "answerSeconds": {
       "type": "number",
       "description": "Mode c: the answer-time threshold in seconds (default 20)"
      },
      "targetBlocking": {
       "type": "number",
       "description": "Mode b: acceptable blocking probability, e.g. 0.01 (default 0.01)"
      },
      "trafficErlangs": {
       "type": "number",
       "description": "Offered load A in erlangs = arrival rate x average handling time (e.g. 120 calls/hour x 3 min = 6 E)"
      },
      "handlingSeconds": {
       "type": "number",
       "description": "Mode c: average handling time in seconds (default 180)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "mode": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "neighbours": {
       "type": [
        "array",
        "null"
   
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/erlang-b-c-staffing-calculator-25aeccc0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from data-calc.x402tookit.com](https://www.zero.xyz/host/data-calc.x402tookit.com/llms.txt)