Verified Tariff API

Overview

Base URL: https://powerexpertindia.com/v1

API version: PEI Verified Tariff API V1.2.0

Controller: PEI Unified Bihar + Maharashtra Controller V2.2.8

Release ID: BR-2026-27-VERIFIED-STRICT-BASE-V1

Authentication

Every API request requires a dedicated client key. Use one of the following header methods.

X-API-Key

export PEI_API_KEY='pei_live_your_key_here'

curl --request GET \
  --url 'https://powerexpertindia.com/v1/health' \
  --header 'Accept: application/json' \
  --header "X-API-Key: ${PEI_API_KEY}"

Authorization: Bearer

export PEI_API_KEY='pei_live_your_key_here'

curl --request GET \
  --url 'https://powerexpertindia.com/v1/states' \
  --header 'Accept: application/json' \
  --header "Authorization: Bearer ${PEI_API_KEY}"

Each key has its own scopes, state allowlist, CORS allowlist and rate-limit profile.

Response contract

{
  "status": "ok",
  "api_version": "PEI Verified Tariff API V1.2.0",
  "request_id": "req_...",
  "data": {},
  "meta": {}
}

{
  "status": "error",
  "api_version": "PEI Verified Tariff API V1.2.0",
  "request_id": "req_...",
  "error": {
    "code": "API_KEY_REQUIRED",
    "message": "A valid API key is required."
  }
}

Every response includes an X-Request-ID header and matching request_id field for support and traceability. Money uses integer paise. A corresponding *_rupees two-decimal string may be returned beside a paise field.

Endpoints

GET /capabilities

Use this route before calculation when an integration needs to distinguish production-enabled features from evidence-only or blocked components.

export PEI_API_KEY='pei_live_your_key_here'

curl --request GET \
  --url 'https://powerexpertindia.com/v1/capabilities?state_code=BR' \
  --header 'Accept: application/json' \
  --header "X-API-Key: ${PEI_API_KEY}"

Capability status summary

{
  "base_tariff_calculation": "enabled",
  "subsidy_entitlement": "enabled_non_monetary",
  "fppas": "historical_evidence_available_current_blocked",
  "monetary_subsidy_amount": "blocked",
  "current_fppas_numeric_regime": "blocked",
  "statutory_levies": "blocked",
  "exact_current_net_bill": "blocked"
}

GET /subsidy-entitlement

This route exposes the verified Bihar domestic 125-unit entitlement contract. The frozen official billing-day examples remain fail-closed: 25 days → 104 units, 30 days → 125 units and 40 days → 167 units. In POST /calculate, supported domestic requests may additionally use the verified monetary subsidy core.

export PEI_API_KEY='pei_live_your_key_here'

curl --request GET \
  --url 'https://powerexpertindia.com/v1/subsidy-entitlement?state_code=BR&consumer_class=domestic&billing_days=30&consumption_units=126' \
  --header 'Accept: application/json' \
  --header "X-API-Key: ${PEI_API_KEY}"

Selected evaluation fields

{
  "billing_days": 30,
  "entitlement_units": 125,
  "consumption_units": 126,
  "subsidised_units": 125,
  "chargeable_units": 1,
  "contract_application": "official_example_exact_match",
  "monetary_calculation_performed": false
}

GET /fppas-periods

This route provides verified Bihar FPPAS period evidence. Filters may be applied by period month, recovery month or authority. POST /calculate may use only an explicitly approved exact-month FPPAS version whose recovery-month and billing-contract conditions match.

export PEI_API_KEY='pei_live_your_key_here'

curl --request GET \
  --url 'https://powerexpertindia.com/v1/fppas-periods?state_code=BR&authority=SBPDCL&period_month=2026-01' \
  --header 'Accept: application/json' \
  --header "X-API-Key: ${PEI_API_KEY}"

Current serving boundary

{
  "available_period_months": [
    "2025-08",
    "2026-01",
    "2026-02",
    "2026-03"
  ],
  "current_rate_released": false,
  "current_fppas_engine_ready": false,
  "historical_evidence_only": true,
  "rate_applied_to_bill": false
}

POST /solar-savings

One-call Bihar domestic solar workflow for solar companies. The endpoint resolves a caller-declared domestic classification, calculates verified before-solar and after-solar base-tariff costs, evaluates optional approved FPPAS data and returns proposal evidence.

One-call request

curl -X POST "https://powerexpertindia.com/v1/solar-savings" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
    "state_code": "BR",
    "consumer_type": "domestic",
    "domestic_class": "urban",
    "connected_load": "2",
    "load_unit": "kw",
    "existing_monthly_units": 450,
    "post_solar_import_units": 150,
    "billing_month": "2026-05",
    "discom_code": "SBPDCL",
    "verification_tier": "verified_strict",
    "release_id": "BR-2026-27-VERIFIED-STRICT-BASE-V1"
  }'

Request fields

Domestic class mapping

Important response objects

Common errors

POST /calculate

Send Content-Type: application/json. Use category metadata from GET /categories to determine which load or demand fields are required for a subcategory.

Domestic request with subsidy and payable evaluation

export PEI_API_KEY='pei_live_your_key_here'

curl --request POST \
  --url 'https://powerexpertindia.com/v1/calculate' \
  --header 'Accept: application/json' \
  --header 'Content-Type: application/json' \
  --header "X-API-Key: ${PEI_API_KEY}" \
  --data '{
    "state_code": "BR",
    "subcategory_code": "BR_DS_II",
    "energy_units": 126,
    "connected_load": "1",
    "billing_days": 30
  }'

Selected response fields

{
  "status": "ok",
  "api_version": "PEI Verified Tariff API V1.2.0",
  "request_id": "req_...",
  "data": {
    "state_code": "BR",
    "subcategory_code": "BR_DS_II",
    "calculation_scope": "verified_base_tariff_plus_non_monetary_subsidy_entitlement",
    "result": {
      "energy_charge_paise": 93492,
      "fixed_charge_paise": 8000,
      "fixed_charge_basis": "per_kw_or_part_per_month",
      "base_total_paise": 101492,
      "base_total_paise_rupees": "1014.92",
      "currency": "INR",
      "integer_paise_only": true
    },
    "subsidy_entitlement": {
      "status": "evaluated_non_monetary",
      "billing_days": 30,
      "entitlement_units": 125,
      "consumption_units": 126,
      "subsidised_units": 125,
      "chargeable_units": 1,
      "monetary_subsidy_amount_paise": null,
      "monetary_calculation_performed": false,
      "base_tariff_amount_adjusted_for_subsidy": false,
      "fppas_included": false
    },
    "excluded_components": [
      "monetary_subsidy_amount",
      "fppas_fpppa",
      "corrigendum_composition",
      "statutory_levies"
    ]
  },
  "meta": {
    "release_id": "BR-2026-27-VERIFIED-STRICT-BASE-V1",
    "controller_version": "PEI Unified Bihar + Maharashtra Controller V2.2.8"
  }
}

Client examples

const response = await fetch(
  'https://powerexpertindia.com/v1/tariffs?state_code=BR&subcategory_code=BR_DS_II',
  {
    method: 'GET',
    headers: {
      'Accept': 'application/json',
      'X-API-Key': apiKey
    }
  }
);

const payload = await response.json();

if (!response.ok) {
  throw new Error(`${payload.error.code}: ${payload.error.message}`);
}

console.log(payload.data);

<?php
$apiKey = getenv('PEI_API_KEY');
$url = 'https://powerexpertindia.com/v1/categories?state_code=BR';

$curl = curl_init($url);
curl_setopt_array($curl, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Accept: application/json',
        'Authorization: Bearer ' . $apiKey,
    ],
    CURLOPT_CONNECTTIMEOUT => 10,
    CURLOPT_TIMEOUT => 30,
]);

$body = curl_exec($curl);
$status = (int) curl_getinfo($curl, CURLINFO_HTTP_CODE);

if ($body === false) {
    throw new RuntimeException(curl_error($curl));
}

curl_close($curl);
$data = json_decode($body, true, 64, JSON_THROW_ON_ERROR);

if ($status >= 400) {
    throw new RuntimeException(
        ($data['error']['code'] ?? 'API_ERROR') . ': ' .
        ($data['error']['message'] ?? 'Request failed')
    );
}

Browser access also requires the page origin to be present in the client key’s CORS allowlist. Server-to-server requests do not send a browser Origin header.

Standard errors

Rate limits

The launch default is 60 requests per minute per API key, with a 20-request burst allowance within 10 seconds. Limits are registry-driven and may differ by client agreement.

Clients should respect Retry-After and use bounded exponential backoff rather than immediate retry loops.

Security and privacy

• Dedicated API keys are accepted only in request headers.
• The protected registry stores SHA-256 key hashes rather than plaintext keys.
• Every key has route scopes, a state allowlist, a CORS allowlist and its own rate-limit configuration.
• Public output excludes raw evidence bodies, text windows and filesystem paths.
• Request logging is privacy-safe and does not record the dedicated API key.
• The calculation endpoint is deterministic and uses integer-paise money arithmetic.
• Evidence-only routes do not silently promote historical or partial evidence into current payable-bill logic.

Release evidence

Current release: BR-2026-27-VERIFIED-STRICT-BASE-V1. Public contract changes require a versioned documentation and OpenAPI update plus complete regression review before monetary or current-regime capabilities are enabled.

Maharashtra — Verified Base Tariff Phase 1

Maharashtra Phase 1 provides verified base-tariff calculation and reference data using human-verified tariff rows and traceable evidence. It is not represented as exact utility-bill reproduction.

Included

• Verified base tariff for MSEDCL, TPC-D, AEML and BEST.
• Licensee-specific category and tariff lookup.
• Verified fixed, energy, wheeling and published variable tariff components where applicable.
• Evidence metadata and SHA-256 traceability.
• FAC/FPPPA/PPCA and ToD status or shadow information where verified/context is available.

Not included in payable total

• FAC/FPPPA/FPPAS/PPCA payable adjustment.
• Time-of-Day payable adjustment.
• Subsidy.
• Electricity duty, tax, cess or other statutory levies.
• Meter rent, arrears, penalties/DPS and miscellaneous ancillary charges.

Maharashtra licensee codes

MH_MSEDCL, MH_TPCD, MH_AEML, MH_BEST