# Materials Optical Band-Gap Fit

> Materials Optical Band-Gap Fit is a paid API for AI agents from www.mahastrategies.com, paid per call via x402, $0.109001/call, status unknown (last checked 2026-10-21).

Fits a Tauc-plot model to supplied optical absorption data to extract the band-gap energy for a specified electronic transition type over a caller-defined fit window.

## Facts

- Endpoint: POST https://www.mahastrategies.com/api/v1/micro/materials-optical-bandgap-fit?utm_source=zero.xyz
- Price: $0.109001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/materials-optical-band-gap-fit-5c3c890b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5s4n17ZEL7GwK9QB4TVMj

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 materials-optical-band-gap-fit-5c3c890b -d '<json body>'
```

Example prompt: Fit a direct-allowed Tauc model to my optical absorption data — I have 50 energy values in eV and corresponding absorption coefficients in per-meter, and I want to use indices 5 through 45 as the fit window. The data is synthetic.

## When to prefer this

Choose this endpoint when you need a reproducible, auditable Tauc-plot band-gap fit for a specific absorption dataset with explicit control over the fit window and transition model type. It is ideal for materials scientists, photovoltaics researchers, or automated pipelines that need a per-call paid, receipt-verified computation rather than running local fitting code. Prefer it over generic curve-fitting services when the direct-allowed vs indirect-allowed Tauc formalism is specifically required.

## Known failure modes

- fitStartIndex >= fitEndIndex causes invalid window error
- array lengths for energyEV and absorptionPerM do not match, leading to rejection
- index values outside allowed range (0–127) are rejected
- mixed DNA/non-numeric values in energy or absorption arrays cause validation failure
- unsupported transition enum value returns schema validation error
- data class not set to 'public' or 'synthetic' triggers enum rejection

## How this service works

Evaluate supplied absorption observations under a declared band-gap model with fit-window sensitivity. No universal band-gap or integrated-device performance claim.

## Output

Returns a structured result object containing the fitted band-gap value and fit quality metrics, along with the boundaries array used for the fit, a versioned offer ID, an input digest for reproducibility, and a receipt digest for payment verification.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "dataClass",
      "energyEV",
      "absorptionPerM",
      "transition",
      "fitStartIndex",
      "fitEndIndex"
     ],
     "properties": {
      "energyEV": {
       "type": "array",
       "maxItems": 128,
       "minItems": 1
      },
      "dataClass": {
       "enum": [
        "public",
        "synthetic"
       ],
       "type": "string"
      },
      "transition": {
       "enum": [
        "direct-allowed",
        "indirect-allowed"
       ],
       "type": "string"
      },
      "fitEndIndex": {
       "type": "integer",
       "maximum": 127,
       "minimum": 2
      },
      "fitStartIndex": {
       "type": "integer",
       "maximum": 125,
       "minimum": 0
      },
      "absorptionPerM": {
       "type": "array",
       "maxItems": 128,
       "minItems": 1
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "version",
      "offerId",
      "amountBaseUnits",
      "inputDigest",
      "result",
      "boundaries",
      "receiptDigest"
     ],
     "properties": {
      "result": {
       "type": "object"
      },
      "offerId": {
       "enum": [
        "materials-optical-bandgap-fit"
       ],
       "type": "string"
      },
      "version": {
       "enum": [
        "maha-microproducts/0.1"
       ],
       "type": "string"
      },
      "boundaries": {
       "type": "array",
       "maxItems": 128,
       "minItems": 0
      },
      "inputDigest": {
       "type": "string",
       "maxLength": 71
      },
      "receiptDigest": {
       "type": "string",
       "maxLength": 71
      },
      "amountBaseUnits": {
       "enum": [
        "109001"
       ],
       "type": "string"
      }
     },
     "add
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/materials-optical-band-gap-fit-5c3c890b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.mahastrategies.com](https://www.zero.xyz/host/www.mahastrategies.com/llms.txt)