WattTime

WattTime is a nonprofit organization that provides real-time, forecast, and historical data for electric grids around the world, enabling carbon-aware computing and clean energy procurement decisions. The WattTime API delivers marginal emissions data (CO2 MOER), health damage signals, average emissions rates, and renewable energy forecasts for 342 grid regions across 210 countries and territories. Developers and organizations use the API to schedule workloads during low-carbon windows, measure actual emissions reductions from clean energy procurement, and meet sustainability reporting requirements.

WattTime publishes 5 APIs on the APIs.io network, including Account API, Authentication API, Emissions Data API, and 2 more. Tagged areas include Emissions, Climate, Carbon, Energy, and Electricity Grid.

The WattTime catalog on APIs.io includes 1 JSON-LD context and 2 Spectral governance rulesets.

WattTime’s developer surface includes authentication, developer portal, documentation, release notes, support, engineering blog, and 9 more developer resources.

🌐 Visit website 📡 Source on GitHub

51.8/100 developing ▼ -11.7 Agent 44/100 agent ready Full breakdown ↓
scored 2026-07-28 · rubric v0.6

AccessFreemiumSelf serve⚡ Free to try

6 APIs 7 Features 5 Use Cases

EmissionsClimateCarbonEnergyElectricity GridSustainabilityClean Energy

Kin Score

Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6

Composite quality — 51.8/100 · developing

Contract Quality 17.6 / 25

Developer Ergonomics 7.8 / 20

Commercial Clarity 7.9 / 20

Operational Transparency 8.9 / 13

Governance 8.3 / 12

Discoverability 6.5 / 10

Agent readiness — 44/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/watttime: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 6

Individual APIs this provider publishes, each with its own machine-readable definition.

WattTime Python Client

Official Python SDK for the WattTime API providing simplified access to real-time, forecast, and historical emissions data.

WattTime Account API

Account information and access management.

WattTime Authentication API

WattTime Emissions Data API

Access real-time, historical, and forecast marginal emissions signals for electric grids.

WattTime Forecasts API

Retrieve emissions forecasts and historical forecast data.

WattTime Grid Regions API

Discover and query grid balancing authorities and regions.

Postman Collections 5

Ready-to-run Postman collections for exercising this provider's APIs.

WattTime Account API

POSTMAN

WattTime Account Authentication API

POSTMAN

WattTime Account Emissions Data API

POSTMAN

WattTime Account Forecasts API

POSTMAN

WattTime Account Grid Regions API

POSTMAN

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

WattTime API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Watttime Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Watttime Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Watttime Finops

FINOPS

Features 7

Notable capabilities this provider offers.

Real-Time Marginal Emissions

CO2 MOER signal providing real-time marginal carbon intensity for local grid regions, updated every 5 minutes via the forecast endpoint.

Emissions Forecasting

24-72 hour ahead emissions forecasts enabling applications to schedule energy-intensive workloads during low-carbon grid windows.

Historical Data Access

Historical MOER data available for up to 32 days via the data endpoint, and multi-year historical datasets downloadable as CSV files.

Health Damage Signal

Estimates the damage to human life and health caused by emissions from electricity generation based on time and location of consumption.

Global Grid Coverage

Coverage across 342 grid regions in 210 countries and territories, including North America, Europe, and global expansion with synthetic demand proxy models.

Grid Region Discovery

Identify the relevant balancing authority for any geographic coordinates and retrieve the list of accessible grid regions.

Model Versioning

Date-based model versioning (e.g., 2026-03-01) allowing unique versions per region and signal for reproducibility and comparison.

Scroll for all 7

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Watttime Context

13 classes · 25 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs.

WattTime API Rules

5 rules · 4 warnings 1 info

SPECTRAL

WattTime API Rules

39 rules · 13 errors 25 warnings 1 info

SPECTRAL

JSON Schema 13

Standalone JSON Schema definitions for this provider's data models.

DataMeta

4 properties

JSON SCHEMA

DataPoint

3 properties

JSON SCHEMA

DataResponse

2 properties

JSON SCHEMA

ForecastMeta

5 properties

JSON SCHEMA

ForecastResponse

2 properties

JSON SCHEMA

GridMapsResponse

2 properties

JSON SCHEMA

HistoricalDownloadResponse

4 properties

JSON SCHEMA

LoginResponse

1 properties

JSON SCHEMA

MyAccessResponse

2 properties

JSON SCHEMA

RegionAccess

6 properties

JSON SCHEMA

RegionResponse

3 properties

JSON SCHEMA

RegisterRequest

4 properties

JSON SCHEMA

RegisterResponse

2 properties

JSON SCHEMA

Scroll for all 13

JSON Structure 13

JSON Structure definitions describing this provider's data shapes.

Watttime Data Meta Structure

4 properties

JSON STRUCTURE

Watttime Data Point Structure

3 properties

JSON STRUCTURE

Watttime Data Response Structure

2 properties

JSON STRUCTURE

Watttime Forecast Meta Structure

5 properties

JSON STRUCTURE

Watttime Forecast Response Structure

2 properties

JSON STRUCTURE

Watttime Grid Maps Response Structure

2 properties

JSON STRUCTURE

Watttime Historical Download Response Structure

4 properties

JSON STRUCTURE

Watttime Login Response Structure

1 properties

JSON STRUCTURE

Watttime My Access Response Structure

2 properties

JSON STRUCTURE

Watttime Region Access Structure

6 properties

JSON STRUCTURE

Watttime Region Response Structure

3 properties

JSON STRUCTURE

Watttime Register Request Structure

4 properties

JSON STRUCTURE

Watttime Register Response Structure

2 properties

JSON STRUCTURE

Scroll for all 13

Examples 13

Example request and response payloads for these APIs.

Watttime Data Meta Example

4 fields

EXAMPLE

Watttime Data Point Example

3 fields

EXAMPLE

Watttime Data Response Example

2 fields

EXAMPLE

Watttime Forecast Meta Example

5 fields

EXAMPLE

Watttime Forecast Response Example

2 fields

EXAMPLE

Watttime Grid Maps Response Example

2 fields

EXAMPLE

Watttime Historical Download Response Example

4 fields

EXAMPLE

Watttime Login Response Example

1 fields

EXAMPLE

Watttime My Access Response Example

2 fields

EXAMPLE

Watttime Region Access Example

6 fields

EXAMPLE

Watttime Region Response Example

3 fields

EXAMPLE

Watttime Register Request Example

4 fields

EXAMPLE

Watttime Register Response Example

2 fields

EXAMPLE

Scroll for all 13

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Watttime Authentication

http · 2 schemes

SECURITY

Watttime Domain Security

TLSv1.3

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Watttime Agentic Access

9 operations · 1 acting

AGENTIC

Use Cases 5

What developers build with this provider.

Carbon-Aware Computing

Technology companies and cloud providers schedule compute workloads, data transfers, and batch jobs to run during periods of low marginal carbon intensity.

Clean Energy Procurement

Organizations measure the actual emissions reductions from renewable energy procurement and power purchase agreements using marginal emissions data.

Sustainability Reporting

Enterprises report Scope 2 emissions more accurately using marginal emissions rates rather than average grid emission factors.

Smart Building Optimization

Building energy management systems shift heating, cooling, and EV charging to low-emission grid windows to reduce carbon footprint.

Grid Research and Analysis

Researchers, utilities, and policy makers analyze historical and forecast emissions data to study grid decarbonization trends.

Integrations 3

Pre-built integrations with other platforms and tools.

Green Software Foundation

WattTime provides the carbon intensity data underlying the Green Software Foundation's Software Carbon Intensity (SCI) specification.

Climate TRACE

WattTime contributes emissions data and modeling to the Climate TRACE global emissions inventory.

Impact Framework

Official Green Software Foundation Impact Framework plugin available for integrating WattTime data into software sustainability measurements.

Resources

Get Started 1

Portal, sign-up, and the first successful call

WattTime Website

Portal

Documentation 1

Reference material describing how the API behaves

API Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

WattTime Spectral Rules

SpectralRules

WattTime Vocabulary

Vocabulary

WattTime JSON-LD Context

JSONLD

Build 2

SDKs, sample code, and the tooling you integrate with

PostmanWorkspace

PostmanWorkspace

WattTime GitHub Organization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 3

Status, limits, changes, and where to get help

API Release Notes

ReleaseNotes

API Status Page

StatusPage

Support Email

Support

Company 2

The organization behind the API

LinkedIn

Blog

Blog

Source (apis.yml)

aid: watttime
name: WattTime
description: WattTime is a nonprofit organization that provides real-time, forecast, and historical data for electric grids
  around the world, enabling carbon-aware computing and clean energy procurement decisions. The WattTime API delivers marginal
  emissions data (CO2 MOER), health damage signals, average emissions rates, and renewable energy forecasts for 342 grid regions
  across 210 countries and territories. Developers and organizations use the API to schedule workloads during low-carbon windows,
  measure actual emissions reductions from clean energy procurement, and meet sustainability reporting requirements.
type: Index
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
position: Consumer
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/watttime.png
url: https://raw.githubusercontent.com/api-evangelist/watttime/refs/heads/main/apis.yml
tags:
- Emissions
- Climate
- Carbon
- Energy
- Electricity Grid
- Sustainability
- Clean Energy
created: '2025-05-02'
modified: '2026-05-19'
specificationVersion: '0.19'
apis:
- aid: watttime:watttime-python-client
  name: WattTime Python Client
  description: Official Python SDK for the WattTime API providing simplified access to real-time, forecast, and historical
    emissions data.
  humanURL: https://github.com/WattTime/watttime-python-client
  tags:
  - Python
  - SDK
  - Client Library
  properties:
  - type: SDKs
    url: https://pypi.org/project/watttime/
    title: Python SDK (PyPI)
  - type: CodeExamples
    url: https://github.com/WattTime/watttime-python-client
    title: Python Client Examples
- aid: watttime:watttime-account-api
  name: WattTime Account API
  description: Account information and access management.
  humanURL: https://docs.watttime.org/
  baseURL: https://api.watttime.org/v3
  tags:
  - Account
  properties:
  - type: OpenAPI
    url: openapi/watttime-account-api-openapi.yml
  - type: Documentation
    url: https://docs.watttime.org/
  - type: Documentation
    url: https://legacy-docs.watttime.org/
  - type: JSONSchema
    url: json-schema/watttime-data-point-schema.json
  - type: JSONSchema
    url: json-schema/watttime-data-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-forecast-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-region-response-schema.json
  - type: JSONStructure
    url: json-structure/watttime-data-point-structure.json
  - type: JSONStructure
    url: json-structure/watttime-data-response-structure.json
- aid: watttime:watttime-authentication-api
  name: WattTime Authentication API
  description: Register for an account and obtain access tokens.
  humanURL: https://docs.watttime.org/
  baseURL: https://api.watttime.org/v3
  tags:
  - Authentication
  properties:
  - type: OpenAPI
    url: openapi/watttime-authentication-api-openapi.yml
  - type: Documentation
    url: https://docs.watttime.org/
  - type: Documentation
    url: https://legacy-docs.watttime.org/
  - type: JSONSchema
    url: json-schema/watttime-data-point-schema.json
  - type: JSONSchema
    url: json-schema/watttime-data-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-forecast-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-region-response-schema.json
  - type: JSONStructure
    url: json-structure/watttime-data-point-structure.json
  - type: JSONStructure
    url: json-structure/watttime-data-response-structure.json
- aid: watttime:watttime-emissions-data-api
  name: WattTime Emissions Data API
  description: Access real-time, historical, and forecast marginal emissions signals for electric grids.
  humanURL: https://docs.watttime.org/
  baseURL: https://api.watttime.org/v3
  tags:
  - Emissions Data
  properties:
  - type: OpenAPI
    url: openapi/watttime-emissions-data-api-openapi.yml
  - type: Documentation
    url: https://docs.watttime.org/
  - type: Documentation
    url: https://legacy-docs.watttime.org/
  - type: JSONSchema
    url: json-schema/watttime-data-point-schema.json
  - type: JSONSchema
    url: json-schema/watttime-data-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-forecast-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-region-response-schema.json
  - type: JSONStructure
    url: json-structure/watttime-data-point-structure.json
  - type: JSONStructure
    url: json-structure/watttime-data-response-structure.json
- aid: watttime:watttime-forecasts-api
  name: WattTime Forecasts API
  description: Retrieve emissions forecasts and historical forecast data.
  humanURL: https://docs.watttime.org/
  baseURL: https://api.watttime.org/v3
  tags:
  - Forecasts
  properties:
  - type: OpenAPI
    url: openapi/watttime-forecasts-api-openapi.yml
  - type: Documentation
    url: https://docs.watttime.org/
  - type: Documentation
    url: https://legacy-docs.watttime.org/
  - type: JSONSchema
    url: json-schema/watttime-data-point-schema.json
  - type: JSONSchema
    url: json-schema/watttime-data-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-forecast-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-region-response-schema.json
  - type: JSONStructure
    url: json-structure/watttime-data-point-structure.json
  - type: JSONStructure
    url: json-structure/watttime-data-response-structure.json
- aid: watttime:watttime-grid-regions-api
  name: WattTime Grid Regions API
  description: Discover and query grid balancing authorities and regions.
  humanURL: https://docs.watttime.org/
  baseURL: https://api.watttime.org/v3
  tags:
  - Grid Regions
  properties:
  - type: OpenAPI
    url: openapi/watttime-grid-regions-api-openapi.yml
  - type: Documentation
    url: https://docs.watttime.org/
  - type: Documentation
    url: https://legacy-docs.watttime.org/
  - type: JSONSchema
    url: json-schema/watttime-data-point-schema.json
  - type: JSONSchema
    url: json-schema/watttime-data-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-forecast-response-schema.json
  - type: JSONSchema
    url: json-schema/watttime-region-response-schema.json
  - type: JSONStructure
    url: json-structure/watttime-data-point-structure.json
  - type: JSONStructure
    url: json-structure/watttime-data-response-structure.json
common:
- type: PostmanWorkspace
  url: https://www.postman.com/kinlaneapi/watttime/overview
- type: AgenticAccess
  url: agentic-access/watttime-agentic-access.yml
- type: DomainSecurity
  url: security/watttime-domain-security.yml
- type: Authentication
  url: authentication/watttime-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/watttime
- type: Portal
  url: https://watttime.org/
  title: WattTime Website
- type: Documentation
  url: https://docs.watttime.org/
  title: API Documentation
- type: ReleaseNotes
  url: https://watttime.org/data-science/release-notes/
  title: API Release Notes
- type: StatusPage
  url: http://status.watttime.org/
  title: API Status Page
- type: GitHubOrganization
  url: https://github.com/WattTime
  title: WattTime GitHub Organization
- type: Support
  url: mailto:support@watttime.org
  title: Support Email
- type: SpectralRules
  url: rules/watttime-spectral-rules.yml
  title: WattTime Spectral Rules
- type: Vocabulary
  url: vocabulary/watttime-vocabulary.yml
  title: WattTime Vocabulary
- type: JSONLD
  url: json-ld/watttime-context.jsonld
  title: WattTime JSON-LD Context
- type: Features
  data:
  - name: Real-Time Marginal Emissions
    description: CO2 MOER signal providing real-time marginal carbon intensity for local grid regions, updated every 5 minutes
      via the forecast endpoint.
  - name: Emissions Forecasting
    description: 24-72 hour ahead emissions forecasts enabling applications to schedule energy-intensive workloads during
      low-carbon grid windows.
  - name: Historical Data Access
    description: Historical MOER data available for up to 32 days via the data endpoint, and multi-year historical datasets
      downloadable as CSV files.
  - name: Health Damage Signal
    description: Estimates the damage to human life and health caused by emissions from electricity generation based on time
      and location of consumption.
  - name: Global Grid Coverage
    description: Coverage across 342 grid regions in 210 countries and territories, including North America, Europe, and global
      expansion with synthetic demand proxy models.
  - name: Grid Region Discovery
    description: Identify the relevant balancing authority for any geographic coordinates and retrieve the list of accessible
      grid regions.
  - name: Model Versioning
    description: Date-based model versioning (e.g., 2026-03-01) allowing unique versions per region and signal for reproducibility
      and comparison.
- type: UseCases
  data:
  - name: Carbon-Aware Computing
    description: Technology companies and cloud providers schedule compute workloads, data transfers, and batch jobs to run
      during periods of low marginal carbon intensity.
  - name: Clean Energy Procurement
    description: Organizations measure the actual emissions reductions from renewable energy procurement and power purchase
      agreements using marginal emissions data.
  - name: Sustainability Reporting
    description: Enterprises report Scope 2 emissions more accurately using marginal emissions rates rather than average grid
      emission factors.
  - name: Smart Building Optimization
    description: Building energy management systems shift heating, cooling, and EV charging to low-emission grid windows to
      reduce carbon footprint.
  - name: Grid Research and Analysis
    description: Researchers, utilities, and policy makers analyze historical and forecast emissions data to study grid decarbonization
      trends.
- type: Integrations
  data:
  - name: Green Software Foundation
    description: WattTime provides the carbon intensity data underlying the Green Software Foundation's Software Carbon Intensity
      (SCI) specification.
  - name: Climate TRACE
    description: WattTime contributes emissions data and modeling to the Climate TRACE global emissions inventory.
  - name: Impact Framework
    description: Official Green Software Foundation Impact Framework plugin available for integrating WattTime data into software
      sustainability measurements.
- url: https://watttime.org/feed/
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com