D Fetcher

D Fetcher provides a simple web calculator and open JSON API to estimate how long you need sun exposure to achieve a target vitamin D dose. It uses real‑time UV index data, location lookup, skin type, body surface area and age to compute minutes of sunlight needed. The service is free, CORS‑open, and requires no API key, making it easy to integrate into health apps, wearables, or personal dashboards.

D Fetcher is listed with 2 APIs on the APIs.io network. Tagged areas include Vitamin D, Health, Calculator, OpenAPI, and Free.

The D Fetcher catalog on APIs.io includes 1 Spectral governance ruleset.

D Fetcher’s developer surface includes changelog, API reference, and 12 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

17.1/100 emerging Agent 16/100 agent aware Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessOpen

2 APIs 1 MCP Servers

Vitamin DHealth Calculator OpenAPI Free

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 17.1/100 · emerging

Contract Quality 2.0 / 21

Developer Ergonomics 2.0 / 17

Access Clarity 1.8 / 17

Operational Transparency 1.7 / 11

Contract Governance 2.2 / 10

Discoverability 4.8 / 9

Regulatory Posture 1.8 / 15

Agent readiness — 16/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

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

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

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

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/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)

11 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 9.4 — up to +22.7 composite points
Access Clarity scores 10.5 — up to +17.9 composite points
Developer Ergonomics scores 11.9 — up to +17.6 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/dfetcher-com/apis.yml: open an issue on github.com/api-evangelist/dfetcher-com to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

Model Context Protocol (MCP)

measured — observed by APIs.io (documented)

APIs 2

Individual APIs this provider publishes, each with its own machine-readable definition.

D Fetcher API

JSON API for the D Fetcher vitamin D synthesis calculator.

D Fetcher API

D Fetcher API as documented publicly: 1 operations. Contract generated from the documentation by API Evangelist (2026-11-05); not the provider's own document.

MCP Servers 1

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

D Fetcher MCP Server

Remote MCP server at dfetcher.com.

MCP SERVER

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

D Fetcher API Rules

26 rules · 24 errors 1 warnings 1 info

SPECTRAL

Security Posture 1

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

Dfetcher Com Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Documentation 1

Reference material describing how the API behaves

APIReference

APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

MCPServer

MCPServer

Design & Contract 4

Pagination, idempotency, versioning, errors, and events

Spectral

Vocabulary

Conformance

Versioning

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

ChangeLog

ChangeLog

HelpCenter

HelpCenter

Commercial 1

Pricing, plans, and the legal terms of use

PrivacyPolicy

PrivacyPolicy

Company 1

The organization behind the API

Website

Website

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: dfetcher-com
name: D Fetcher
accessModel:
  pricing: unknown
  onboarding: open
  trial: false
  try_now: false
  public: true
  gated: none
  gated_source:
  - onboarding
  label: Open access
  confidence: low
  source:
  - security
  generated: '2026-11-06'
  method: derived
image: https://dfetcher.com/og.png
description: D Fetcher provides a simple web calculator and open JSON API to estimate how long you need sun exposure to achieve
  a target vitamin D dose. It uses real‑time UV index data, location lookup, skin type, body surface area and age to compute
  minutes of sunlight needed. The service is free, CORS‑open, and requires no API key, making it easy to integrate into health
  apps, wearables, or personal dashboards.
url: https://artifacts.apis.io/dfetcher-com/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-11-05 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-11-05'
modified: '2026-11-05'
tags:
- Vitamin D
- Health
- Calculator
- OpenAPI
- Free
tags_raw:
- Vitamin D
- Health
- Calculator
- Open API
- Free
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Spectral
  url: rules/dfetcher-com-rules.yml
- type: Vocabulary
  url: vocabulary/dfetcher-com-vocabulary.yml
- type: ChangeLog
  url: changelog/dfetcher-com-changelog.yml
- type: Conformance
  url: conformance/dfetcher-com-conformance.yml
- type: LLMsTxt
  url: llms/dfetcher-com-llms.txt
- type: MCPServer
  url: mcp/dfetcher-com-mcp.yml
- type: Hosts
  url: hosts/dfetcher-com-hosts.yml
- type: Vendors
  url: vendors/dfetcher-com-vendors.yml
- type: DomainSecurity
  url: security/dfetcher-com-domain-security.yml
- type: Website
  url: https://dfetcher.com/
- type: APIReference
  url: https://dfetcher.com/api
- type: HelpCenter
  url: https://dfetcher.com/faq
- type: Versioning
  url: https://dfetcher.com/changelog
- type: PrivacyPolicy
  url: https://dfetcher.com/privacy
apis:
- name: D Fetcher API
  description: JSON API for the D Fetcher vitamin D synthesis calculator.
  humanURL: https://dfetcher.com/api
  baseURL: https://dfetcher.com/api
  specification:
    type: none
  x-coverage:
    state: unreadable
    reason: no-machine-readable-spec
    detail: Provider offers an HTML API reference page but no machine‑readable OpenAPI/GraphQL/AsyncAPI spec.
    evidence:
    - url: https://dfetcher.com/api
      status: 200
    checked: '2026-11-05'
  aid: dfetcher-com:d-fetcher-api
- aid: dfetcher-com:dfetcher-com-api
  name: D Fetcher API
  description: 'D Fetcher API as documented publicly: 1 operations. Contract generated from the documentation by API Evangelist
    (2026-11-05);

    not the provider''s own document.'
  humanURL: https://dfetcher.com/api
  properties:
  - type: OpenAPI
    url: openapi/_ae-authored/dfetcher-com-openapi-generated.yml
    x-provenance: generated
x-enrichment:
  date: '2026-11-05'
  status: enriched
  artifacts_added: 15
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

D Fetcher API — frequently asked questions

Does D Fetcher have an API?

Yes. APIs.io lists 2 APIs from D Fetcher, including D Fetcher API and D Fetcher API.

Is there an OpenAPI specification for the D Fetcher API?

Yes. APIs.io indexes 1 OpenAPI specification for D Fetcher, each linked for download from this page.

Does D Fetcher have an MCP server?

Yes. APIs.io lists 1 MCP server for D Fetcher: Remote MCP server at dfetcher.com.

Is the D Fetcher API ready for AI agents?

D Fetcher has a Kin Score of 17.1 out of 100 (emerging) and an Agent Readiness score of 16.4 (agent-aware), scored by API Evangelist on 2026-11-06.

Work with this as data

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Tools for providers

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get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
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