B12

B12 is an AI-powered website builder that generates professional websites, online stores, and web apps from a short prompt. Founded on a human-in-the-loop model and now driven by its B12 3.0 AI Agent (launched February 2026), the platform lets solopreneurs, consultants, freelancers, and growing teams describe a business idea and launch a site in minutes, then run that business online with built-in tools for SEO, online payments and invoicing, scheduling, email marketing, client intake, contact management, and contracts with eSignatures. B12 offers self-serve DIY plans as well as Expert plans where its design and content team handles setup and ongoing updates. Over 4 million websites have been built on B12. B12 exposes its website-generation capability to AI agents through a published Model Context Protocol (MCP) server, a Claude plugin, and a Website Generator GPT, but does not publish a general-purpose public REST API.

B12 is profiled on the APIs.io network. Tagged areas include Company, Enterprise, Website Builder, AI, and No-Code.

B12’s developer surface includes support, engineering blog, pricing, signup flow, and 8 more developer resources.

🌐 Visit website 📡 Source on GitHub

21.1/100 emerging ▬ flat Agent 12/100 human only Full breakdown ↓
scored 2026-07-28 · rubric v0.5

0 APIs 1 MCP Servers

CompanyEnterpriseWebsite BuilderAINo-CodeSmall BusinessWebsite GenerationModel Context ProtocolSEOPayments

Kin Score

Kin Score How this is scored →
scored 2026-07-28 · rubric v0.5

Composite quality — 21.1/100 · emerging

Contract Quality 0.0 / 25

Developer Ergonomics 3.0 / 20

Commercial Clarity 8.9 / 20

Operational Transparency 0.7 / 13

Governance 0.0 / 12

Discoverability 6.8 / 10

Agent readiness — 12/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 15

MCP Server 12 / 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/b12: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Get Started 1

Portal, sign-up, and the first successful call

SignUp

SignUp

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

MCPServer

MCPServer

LLMsTxt

LLMsTxt

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

HelpCenter

HelpCenter

Support

Support

Commercial 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: b12
name: B12
description: B12 is an AI-powered website builder that generates professional websites, online stores, and web apps from a
  short prompt. Founded on a human-in-the-loop model and now driven by its B12 3.0 AI Agent (launched February 2026), the
  platform lets solopreneurs, consultants, freelancers, and growing teams describe a business idea and launch a site in minutes,
  then run that business online with built-in tools for SEO, online payments and invoicing, scheduling, email marketing, client
  intake, contact management, and contracts with eSignatures. B12 offers self-serve DIY plans as well as Expert plans where
  its design and content team handles setup and ongoing updates. Over 4 million websites have been built on B12. B12 exposes
  its website-generation capability to AI agents through a published Model Context Protocol (MCP) server, a Claude plugin,
  and a Website Generator GPT, but does not publish a general-purpose public REST API.
url: https://raw.githubusercontent.com/api-evangelist/b12/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://www.b12.io/static-assets/images/ai-website-builder.jpeg
x-type: company
x-source: vc-portfolio
x-backed-by:
- general-catalyst
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-18'
tags:
- Company
- Enterprise
- Website Builder
- AI
- No-Code
- Small Business
- Website Generation
- Model Context Protocol
- SEO
- Payments
apis: []
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://www.b12.io
- type: MCPServer
  name: B12 Website Generator MCP Server
  url: mcp/b12-mcp.yml
- type: LLMsTxt
  url: llms/b12-llms.txt
- type: DomainSecurity
  url: security/b12-domain-security.yml
- type: GitHubOrganization
  url: https://github.com/b12io
- type: HelpCenter
  url: https://support.b12.io/en
- type: Support
  url: https://www.b12.io/support/
- type: Blog
  url: https://www.b12.io/resource-center/
- type: Pricing
  url: https://www.b12.io/pricing/
- type: SignUp
  url: https://b12.io/signup/
- type: TermsOfService
  url: https://www.b12.io/terms-of-service/
- type: PrivacyPolicy
  url: https://www.b12.io/privacy-policy/
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

B12