FitStar

FitStar Labs, Inc. was a San Francisco based consumer fitness company that built FitStar Personal Trainer and FitStar Yoga, adaptive video workout apps that adjusted each session to the user's feedback and fitness level. Backed by GV (Google Ventures) and Trinity Ventures, FitStar was acquired by Fitbit on March 5, 2015 for $17.8 million and folded into the Fitbit Coach product line. The company is DEFUNCT: the fitstar.com domain no longer serves web content (last archived live October 2017), the FitStar apps have been retired, and no developer portal, documentation, or public API surface survives. This profile is retained as a historical record in the API Evangelist network; there is nothing to enrich beyond identity and domain posture.

FitStar is profiled on the APIs.io network. Tagged areas include Company, Defunct, Acquired, Fitness, and Health and Wellness.

📡 Source on GitHub

0.0/100 minimal Agent 0/100 human only Full breakdown ↓
scored 2026-09-25 · rubric v0.23.0

0 APIs

Company Defunct Acquired Fitness Health and Wellness Consumer Applications Mobile App Personal Training

Kin Score

Kin Score How this is scored →
scored 2026-09-25 · rubric v0.23.0

Composite quality — 0.0/100 · minimal

Contract Quality 0.0 / 21

Developer Ergonomics 0.0 / 17

Access Clarity 0.0 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.0 / 10

Discoverability 0.0 / 9

Regulatory Posture 0.7 / 15

Agent readiness — 0/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

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

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Regulatory Posture applies to this provider. Its tags matched the Health regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/fitstar: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Security Posture 1

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

Fitstar Domain Security

DMARC

SECURITY

Resources

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Source (apis.yml)

aid: fitstar
name: FitStar
description: 'FitStar Labs, Inc. was a San Francisco based consumer fitness company that built FitStar Personal Trainer and
  FitStar Yoga, adaptive video workout apps that adjusted each session to the user''s feedback and fitness level. Backed by
  GV (Google Ventures) and Trinity Ventures, FitStar was acquired by Fitbit on March 5, 2015 for $17.8 million and folded
  into the Fitbit Coach product line. The company is DEFUNCT: the fitstar.com domain no longer serves web content (last archived
  live October 2017), the FitStar apps have been retired, and no developer portal, documentation, or public API surface survives.
  This profile is retained as a historical record in the API Evangelist network; there is nothing to enrich beyond identity
  and domain posture.'
url: https://raw.githubusercontent.com/api-evangelist/fitstar/refs/heads/main/apis.yml
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: false
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - none
  generated: '2026-08-28'
  method: derived
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://avatars.githubusercontent.com/u/1479331?v=4
x-type: company
x-source: vc-portfolio
x-status: defunct
x-defunct-reason: acquired
x-acquired-by: fitbit
x-acquired-date: '2015-03-05'
x-acquired-amount-usd: 17800000
x-backed-by:
- gv
- trinity-ventures
x-tier: stub
x-tier-reason: defunct-no-api-surface
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Defunct
- Acquired
- Fitness
- Health and Wellness
- Consumer Applications
- Mobile App
- Personal Training
tags_raw:
- Company
- Defunct
- Acquired
- Fitness
- Health and Wellness
- Consumer Applications
- Mobile Applications
- Personal Training
apis: []
common:
- type: GitHubOrganization
  name: FitStar Labs, Inc. on GitHub
  url: https://github.com/fitstar
- type: DomainSecurity
  name: Domain security posture
  url: security/fitstar-domain-security.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-20'
  status: minimal
  artifacts_added: 1
  pass: local-v1

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