HouseSigma
HouseSigma, Inc. Brokerage is a Toronto-based Canadian residential real estate portal and licensed brokerage that pairs map-based MLS listing search with sold-price history and machine-learning home valuations (SigmaEstimate) across Ontario, British Columbia, and Alberta. It sits in the challenger layer of the Canadian value chain, below CREA, which operates REALTOR.ca and the national Data Distribution Facility (DDF) that syndicates member boards' listings, and alongside Wahi, Zolo, and Properly, competing on visibility into data the boards control, a position it won in part through the Competition Bureau litigation that forced TRREB to release sold data in 2018. Its API posture is closed. There is no developer portal, no published API program, and no partner or data-licensing page; developer., developers., and docs.housesigma.com do not resolve in DNS, and /developers, /api, /api-docs, /openapi.json and /swagger.json all return the single-page-application shell rather than any contract. The listing, sold-history and valuation backend at housesigma.com/bkv2/api/ is private, keyless, undocumented, and explicitly disallowed to all crawlers in robots.txt. The one genuinely public, anonymously callable, machine-readable HTTP surface the company operates is the WordPress REST API behind housesigma.com/blog-en, which serves its Canadian housing-market analysis blog as JSON across 157 advertised routes; API Evangelist derived an OpenAPI for the 22 operations verified to answer anonymously. HouseSigma also publishes a real llms.txt and mobile deep-link association documents. RESO is absent: HouseSigma is not among the Canadian organizations RESO lists as members, and no Web API or Data Dictionary certification, OData $metadata document, or Universal Property Identifier usage was found. No open, unlicensed dataset is published. The underlying listing and sold data is board-licensed and reaches HouseSigma through its own brokerage membership, not through anything a third-party developer can sign up for.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles HouseSigma the way a machine reads it — 9 machine-readable artifacts across 1 API, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — HouseSigma scores 33.1/100 (thin), with a separate agent-readiness read of 64/100 (agent native). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile HouseSigma
Each block below is one kind of artifact we hold for HouseSigma. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 1
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
HouseSigma Blog Content API
The public, read-only WordPress REST API (wp/v2) behind housesigma.com/blog-en, which serves HouseSigma's Canadian housing-market analysis blog as JSON. This is the only anonymo...
Examples 5
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Security Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for HouseSigma — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Agent Surfaces 4
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 6
Pagination, idempotency, versioning, errors, and events
Build 2
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
Operate 2
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 8
The organization behind the API
Scroll within the panel for all 8 ·
Other 3
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/housesigma · machine-readable index on apis.io