# Halowerk Basic Reproduction Number (R0) Calculator

> Halowerk Basic Reproduction Number (R0) Calculator is a paid API for AI agents from bio.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Computes a basic reproduction number (R0) and effective reproduction number (Re) using a simple homogeneous-mixing formula from transmission probability, contact rate, and infectious duration.

## Facts

- Endpoint: POST https://bio.halowerk.com/v1/pathogen-r0
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-basic-reproduction-number-r0-calculator-5484f784
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_c90RuqJzjEzIFhCnmo4s-

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 halowerk-basic-reproduction-number-r0-calculator-5484f784 -d '<json body>'
```

Example prompt: Calculate the basic reproduction number for a pathogen with a 0.05 transmission probability per contact, 10 effective contacts per day, and a 7-day infectious duration — and also give me the effective R if only 60% of the population is susceptible.

## When to prefer this

Choose this endpoint when you need a fast, deterministic textbook R0 computation from first-principles parameters (transmission probability, contact rate, infectious duration) and optionally want Re given a susceptible fraction. It is ideal for educational tools, homework helpers, sensitivity analyses, or any agent workflow that needs a simple numeric reproduction number without fitting real case data or running a full simulation. Do not use it for real outbreak forecasting, fitted epidemiological models, or policy-grade public-health estimates.

## Known failure modes

- Input values out of allowed range (e.g. transmission probability or susceptible fraction outside [0,1], negative durations) return a validation error
- Missing required fields may return an error or default to zero
- Extremely large contact rates or durations (approaching their maximums) may produce unrealistically large R0 values without warning
- The endpoint does not validate biological plausibility — callers must ensure inputs are epidemiologically meaningful

## How this service works

Multiplies per-contact transmission probability, effective contacts per day and infectious duration to obtain a simple basic reproduction number, then applies a susceptible fraction for an effective number. It is a classroom homogeneous-mixing calculation, not an outbreak estimate, fitted epidemiological model or public-health forecast.

## Output

Returns the basic reproduction number R0 (product of transmission probability, effective contacts per day, and infectious duration) and the effective reproduction number Re (R0 multiplied by the susceptible fraction). These are scalar numeric values based on a simple homogeneous-mixing model, not a fitted epidemiological model or real-world outbreak forecast.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "susceptible_fraction": {
   "type": "number",
   "maximum": 1,
   "minimum": 0
  },
  "infectious_duration_days": {
   "type": "number",
   "maximum": 100000,
   "minimum": 0
  },
  "effective_contacts_per_day": {
   "type": "number",
   "maximum": 1000000,
   "minimum": 0
  },
  "transmission_probability_per_contact": {
   "type": "number",
   "maximum": 1,
   "minimum": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-basic-reproduction-number-r0-calculator-5484f784/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bio.halowerk.com](https://www.zero.xyz/host/bio.halowerk.com/llms.txt)