Sumutasu

Sumutasu Inc. (株式会社すむたす) is a Japanese property-technology (proptech) company operating under the mission "a society where people can make ideal housing choices" (住まいの理想的な選択ができる社会に). It runs an instant real-estate buying and selling service for used condominiums in Japan, using data and technology to give homeowners a fast, transparent alternative to the traditional brokerage process, alongside an agent-assisted sales offering. The company is backed by 500 Global. Its public presence is a corporate marketing website (About, Services, Members, News, and Careers) built on the Studio.Design no-code platform; no public developer platform, API, SDK, or documentation surface has been found.

Sumutasu is profiled on the APIs.io network. Tagged areas include Company, Real-Estate, PropTech, Japan, and iBuyer.

Sumutasu’s developer surface includes engineering blog and 3 more developer resources.

🌐 Visit website 📡 Source on GitHub

5.0/100 minimal ▬ flat Agent 0/100 human only Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

0 APIs

Company Real-Estate PropTech Japan iBuyer Housing Marketplace

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 5.0/100 · minimal

Contract Quality 0.0 / 25

Developer Ergonomics 0.0 / 20

Access Clarity 0.0 / 20

Operational Transparency 0.0 / 13

Contract Governance 0.0 / 12

Discoverability 5.0 / 10

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

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.

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/sumutasu: 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.

Sumutasu Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Company 3

The organization behind the API

Website

Website

About

About

Blog

Blog

Source (apis.yml)

aid: sumutasu
name: Sumutasu
description: Sumutasu Inc. (株式会社すむたす) is a Japanese property-technology (proptech) company operating under the mission "a
  society where people can make ideal housing choices" (住まいの理想的な選択ができる社会に). It runs an instant real-estate buying and selling
  service for used condominiums in Japan, using data and technology to give homeowners a fast, transparent alternative to
  the traditional brokerage process, alongside an agent-assisted sales offering. The company is backed by 500 Global. Its
  public presence is a corporate marketing website (About, Services, Members, News, and Careers) built on the Studio.Design
  no-code platform; no public developer platform, API, SDK, or documentation surface has been found.
url: https://raw.githubusercontent.com/api-evangelist/sumutasu/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- 500-global
x-tier: stub
x-tier-reason: portfolio-lead
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
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-21'
tags:
- Company
- Real-Estate
- PropTech
- Japan
- iBuyer
- Housing
- Marketplace
tags_raw:
- Company
- Real Estate
- PropTech
- Japan
- iBuyer
- Housing
- Marketplace
image: https://storage.googleapis.com/production-os-assets/assets/778fe21a-a784-4231-a12e-be19751e0491
apis: []
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://sumutasu.co.jp
- type: About
  url: https://sumutasu.co.jp/about
- type: Blog
  url: https://sumutasu.co.jp/news
- type: DomainSecurity
  url: security/sumutasu-domain-security.yml
x-enrichment:
  date: '2026-07-21'
  status: minimal
  artifacts_added: 1
  pass: local-v1

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