Calpine website screenshot

Calpine

Calpine Corporation was a major U.S. energy company headquartered in Houston, Texas, and was the largest generator of electricity from natural gas and geothermal energy in the United States. It operated 80 power plants with approximately 26,035 megawatts of generation capacity, including The Geysers, the world's largest geothermal complex. Calpine also operated the Champion Energy retail electricity subsidiary serving deregulated markets. As of January 2026, Constellation Energy completed its acquisition of Calpine for $16.4 billion, making it a business unit of Constellation. Calpine does not publish a public developer API program.

Calpine is profiled on the APIs.io network. Tagged areas include Electricity, Energy, Geothermal, Natural Gas, and Power Generation.

Calpine’s developer surface includes engineering blog and 6 more developer resources.

🌐 Visit website 📡 Source on GitHub
7.2/100 minimal ▬ flat Agent 0/100 human only Full breakdown ↓
scored 2026-07-27 · rubric v0.5
0 APIs
ElectricityEnergyGeothermalNatural GasPower GenerationRetail ElectricityUtilitiesFortune 500

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 7.2/100 · minimal
Contract Quality 0.0 / 25
Developer Ergonomics 0.4 / 20
Commercial Clarity 0.0 / 20
Operational Transparency 0.0 / 13
Governance 0.0 / 12
Discoverability 6.8 / 10
Agent readiness — 0/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
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/calpine: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

Security Posture 1

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

Calpine Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Press 8

Recent news and press coverage referencing this provider.

Constellation's $30 Billion Calpine Talks Are Fueled by AI

2026-05-25

Calpine and CyrusOne Announce Phase 2 of Powered ...

2026-05-25

Jordi Vilanova's Post

2026-05-25

Constellation To Acquire Calpine; Creates America's ...

2026-05-25

Constellation Acquisition of Calpine: Creating the Right ...

2026-05-25

Constellation and CyrusOne Announce Agreement to Support New Data Center Facility at Fr...

2026-02-09

Constellation Completes Calpine Transaction, Powering America’s Clean Energy Future

2026-01-07

Constellation Reaches Resolution with U.S. Department of Justice for Calpine Transaction

2025-12-05

Scroll for all 8

Resources

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity

Company 3

The organization behind the API

Website
Website
 LinkedIn
LinkedIn
 Blog
Blog

Other 3

Properties that don't map to a standard resource type

Wikipedia
Wikipedia
 Champion Energy
Champion Energy
 Parent Company
Parent Company

Source (apis.yml)

apis.yml Raw ↑ 
aid: calpine
name: Calpine
url: https://raw.githubusercontent.com/api-evangelist/calpine/refs/heads/main/apis.yml
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/calpine.png
type: Index
tags:
- Electricity
- Energy
- Geothermal
- Natural Gas
- Power Generation
- Retail Electricity
- Utilities
- Fortune 500
created: '2024-01-01'
modified: '2026-04-23'
specificationVersion: '0.19'
description: Calpine Corporation was a major U.S. energy company headquartered in Houston, Texas, and was the largest generator
  of electricity from natural gas and geothermal energy in the United States. It operated 80 power plants with approximately
  26,035 megawatts of generation capacity, including The Geysers, the world's largest geothermal complex. Calpine also operated
  the Champion Energy retail electricity subsidiary serving deregulated markets. As of January 2026, Constellation Energy
  completed its acquisition of Calpine for $16.4 billion, making it a business unit of Constellation. Calpine does not publish
  a public developer API program.
apis: []
common:
- type: DomainSecurity
  url: security/calpine-domain-security.yml
- type: Website
  url: https://www.calpine.com
- type: Wikipedia
  url: https://en.wikipedia.org/wiki/Calpine
- type: Champion Energy
  url: https://www.championenergyservices.com/
- type: Parent Company
  url: https://www.constellationenergy.com/
- type: LinkedIn
  url: https://www.linkedin.com/company/calpine
- url: https://www.calpine.com/feed/
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com