API v3.0

Infrastructure-Grade Carbon Accounting API

Not just a calculator—a complete carbon activity ingestion, normalization, verification, and reporting engine that transforms raw operational data into audit-ready emissions intelligence.

35+ Standardized FieldsConfidence ScoringGit-like Audit TrailDouble-Entry Ledger

What Makes ZeroCarbon API Different?

Canonical Activity Model

Single unbreakable data contract for all emissions. 35+ standardized fields with full type safety and Zod validation.

Confidence Scoring

5-factor weighted algorithm (0-100%) assessing data quality: source quality, completeness, factor quality, temporal accuracy, and methodological rigor.

Git-like Audit Trail

SHA-256 hash chains for every carbon activity. Complete version history with tamper-proof integrity verification.

Carbon Ledger

Double-entry bookkeeping for emissions. Track balance_before, transaction_amount, and balance_after for complete transparency.

Core Architecture

ZeroCarbon API v3 is built on four foundational pillars that ensure data integrity, compliance, and scalability:

1. Canonical Activity Model

Every emission flows through a single, unbreakable data contract with 35+ standardized fields. This ensures consistency across all data sources—whether from manual entry, CSV uploads, ERP integrations, or IoT sensors.

2. Confidence Scoring System

Data quality is quantified using a 5-factor weighted algorithm (0-100% scale):

Source Quality (25%) - Meter data (95%) → API (90%) → Supplier (80%) → Manual (70%) → Estimate (50%)
Data Completeness (25%) - Required fields populated and metadata richness
Emission Factor Quality (20%) - Region-specific → national → global defaults
Temporal Accuracy (15%) - Real-time → daily → monthly → annual
Methodological Rigor (15%) - GHG Protocol Tier 1-4 classification

Confidence Ratings: Excellent (≥85%), Good (70-84%), Fair (55-69%), Poor (<55%)

3. Audit Trail & Version Control

Git-like version control for every carbon activity with SHA-256 hash chains. Track all changes (create, update, delete, recalculate) with tamper-proof integrity verification that meets SEC, CSRD, and BRSR audit requirements.

4. Carbon Ledger (Double-Entry Bookkeeping)

Accounting-grade emission tracking with separate ledgers for Scope 1, 2, and 3. Every transaction records:

Transaction Types: emission_add, emission_reduce, offset_purchase, offset_retire
Balance Tracking: balance_before → transaction_amount → balance_after
Period Snapshots: Frozen period-end balances for regulatory reporting

Quick Example

Here's how to submit an electricity consumption activity with the Node.js SDK:

submit_activity.tstypescript

import { ZeroCarbon } from 'zerocarbon-nodejs-sdk';
import * as dotenv from 'dotenv';

dotenv.config();

// Initialize client
const client = new ZeroCarbon({
  apiKey: process.env.ZEROCARBON_API_KEY!,
  baseUrl: 'https://api.zerocarbon.org.in/v1'
});

// Submit electricity activity
const result = await client.emissions.calculate({
  activity_type: 'electricity',
  quantity: 1500,
  unit: 'kWh',
  location: { country: 'IN', state: 'MH' },
  period: { start: '2026-02-01', end: '2026-02-28' }
});

console.log(`Emissions: ${result.emissions_kg_co2e} kg CO2e`);
console.log(`Confidence: ${result.confidence_score}`);