aid: extensity
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/extensity.png
name: Extensity
description: ExtensityAI is an AI research company building trustworthy, verifiable AI for enterprise
  environments through a neurosymbolic architecture that combines large language models with symbolic
  validation and knowledge-graph reasoning. Its flagship open-source framework, SymbolicAI, treats LLMs
  as programmable, differentiable primitives (Symbol objects) governed by Design-by-Contract validation,
  giving developers source-traceable, contract-enforced AI they can run on-premise with sovereign data
  control. The company also ships developer tooling including the ontoloom MCP server for building and
  exploring OWL 2 ontologies with AI agents. Backed by Lightspeed Venture Partners.
url: https://raw.githubusercontent.com/api-evangelist/extensity/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- lightspeed-venture-partners
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Artificial Intelligence
- Neurosymbolic AI
- Large Language Models
- Knowledge Graphs
- Developer Tools
- Open Source
- Python
- Model Context Protocol
apis: []
common:
- type: DomainSecurity
  url: security/extensity-domain-security.yml
- type: Website
  url: https://extensity.ai
- type: GitHubOrganization
  url: https://github.com/ExtensityAI
- type: Documentation
  url: https://extensityai.gitbook.io/symbolicai
- type: SourceCode
  url: https://github.com/ExtensityAI/symbolicai
- type: Support
  name: Discord Community
  url: https://discord.gg/QYMNnh9ra8
- type: Packages
  url: packages/extensity-packages.yml
- type: SDKs
  url: packages/extensity-packages.yml
- type: MCPServer
  url: mcp/extensity-mcp.yml
- type: LLMsTxt
  url: llms/extensity-llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence