Rex Inc

Rex Inc, operating as Rex.fit (BabylonAI Inc.), is a Y Combinator (W23) health and fitness company building AI-powered, fully automated nutrition tracking. Its consumer products include Rex Nutribot, a WhatsApp AI nutrition coach; the Drop, a wearable AI camera pendant that detects meals and automatically logs calories, protein, carbs, and fats via computer vision; an AI body scanner; and personalized coaching with daily health reports. Rex also offers a white-label B2B nutrition-and-fitness AI that fitness chains and app builders integrate to add meal logging (photo, barcode, or text), recipe and meal-plan generation, workout logging, 3D body scans, and nutrition analytics under their own brand.

Rex Inc is profiled on the APIs.io network. Tagged areas include Company, Health, Fitness, Nutrition, and Artificial Intelligence.

Rex Inc’s developer surface includes developer portal, engineering blog, support, and 6 more developer resources.

🌐 Visit website 📡 Source on GitHub

16.5/100 emerging ▬ flat Agent 0/100 human only Full breakdown ↓
scored 2026-07-27 · rubric v0.5

0 APIs

CompanyHealthFitnessNutritionArtificial IntelligenceComputer VisionWearablesY Combinator

Kin Score

Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5

Composite quality — 16.5/100 · emerging

Contract Quality 0.0 / 25

Developer Ergonomics 3.0 / 20

Commercial Clarity 4.2 / 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

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Get Started 1

Portal, sign-up, and the first successful call

Portal

Portal

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support

Support

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 4

The organization behind the API

Website

Website

Blog

Blog

LinkedIn

Twitter

Twitter

Source (apis.yml)

aid: rex-inc
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/rex-inc.png
name: Rex Inc
description: Rex Inc, operating as Rex.fit (BabylonAI Inc.), is a Y Combinator (W23) health and fitness company building AI-powered,
  fully automated nutrition tracking. Its consumer products include Rex Nutribot, a WhatsApp AI nutrition coach; the Drop,
  a wearable AI camera pendant that detects meals and automatically logs calories, protein, carbs, and fats via computer vision;
  an AI body scanner; and personalized coaching with daily health reports. Rex also offers a white-label B2B nutrition-and-fitness
  AI that fitness chains and app builders integrate to add meal logging (photo, barcode, or text), recipe and meal-plan generation,
  workout logging, 3D body scans, and nutrition analytics under their own brand.
url: https://raw.githubusercontent.com/api-evangelist/rex-inc/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- y-combinator
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Health
- Fitness
- Nutrition
- Artificial Intelligence
- Computer Vision
- Wearables
- Y Combinator
apis: []
common:
- type: DomainSecurity
  url: security/rex-inc-domain-security.yml
- type: Website
  url: https://www.rex.fit
- type: Portal
  name: B2B / White-label API
  url: https://rex.fit/api
- type: Blog
  url: https://rex.fit/blog
- type: Support
  name: Contact
  url: https://rex.fit/contact
- type: TermsOfService
  url: https://rex.fit/terms-of-service
- type: PrivacyPolicy
  url: https://rex.fit/privacy-policy
- type: LinkedIn
  url: https://www.linkedin.com/company/rexfit/
- type: Twitter
  url: https://twitter.com/rexfit_app
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-21'
  status: enriched
  artifacts_added: 1
  pass: local-v1