53ON

53ON is a directory and marketplace of local businesses and independent professionals. It allows users to search by service and area, view ratings and prices, and book and pay in one place, providing a unified platform for discovering and hiring local service providers. The platform supports multiple languages and integrates with various payment gateways, aiming to simplify the process of finding and engaging local expertise.

53ON publishes 2 API contracts indexed on the APIs.io network: S {service} API and Xsite API. Tagged areas include Marketplace, Directory, Local Business, Services, and Consumer.

The 53ON catalog on APIs.io includes 1 Spectral governance ruleset.

🌐 Visit website 📡 Profile data on GitHub

19.8/100 emerging ▬ flat Agent 29/100 agent ready Full breakdown ↓
scored 2026-11-02 · rubric v0.26.0 · Show this score on your site →

1 published contract 1 MCP Servers

Marketplace Directory Local Business Services Consumer Company

Kin Score

Kin Score How this is scored →
scored 2026-11-02 · rubric v0.26.0

Composite quality — 19.8/100 · emerging

Contract Quality 10.0 / 21

Developer Ergonomics 0.0 / 17

Access Clarity 0.0 / 17

Operational Transparency 0.0 / 11

Contract Governance 1.9 / 10

Discoverability 5.5 / 9

Regulatory Posture 1.6 / 15

Agent readiness — 29/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 4 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 8 / 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 Horizontal (data, software, accessibility, platform) 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):

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)
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)

7 more unmet checks in the Agent Readiness table above.

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

Developer Ergonomics scores 0.0 — up to +20.0 composite points
Access Clarity scores 0.0 — up to +20.0 composite points
Contract Quality scores 47.1 — up to +13.2 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/53on-com/apis.yml: open an issue on github.com/api-evangelist/53on-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 3

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.

Agent2Agent

measured — observed by APIs.io (conformant)

Model Context Protocol (MCP)

measured — observed by APIs.io (documented)

OpenAPI

measured — observed by APIs.io (published)

APIs 2

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

53ON S {service} API

The S {service} API from 53ON — 1 operation(s) for s {service}.

53ON Xsite API

The Xsite API from 53ON — 2 operation(s) for xsite.

MCP Servers 1

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

53ON MCP Server

Remote MCP server at 53on.com.

MCP SERVER

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

53ON API Rules

12 rules · 10 errors 1 warnings 1 info

SPECTRAL

Security Posture 1

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

53On Com Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

53On Com Agentic Access

3 operations · 1 acting · 1 human-in-the-loop

3 operations · 1 acting

AGENTIC

Resources

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

LLMsTxt

MCPServer

WellKnown

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Spectral

Spectral

ErrorCatalog

ErrorCatalog

Conformance

Conformance

Build 1

SDKs, sample code, and the tooling you integrate with

ToolCrosswalk

ToolCrosswalk

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Company 1

The organization behind the API

Website

Website

Other 3

Properties that don't map to a standard resource type

AgentCard

AgentCard

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: 53on-com
name: 53ON
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - security
  generated: '2026-11-02'
  method: derived
image: https://53on.com/xsite/public/assets/img/53ONmeta.png
description: 53ON is a directory and marketplace of local businesses and independent professionals. It allows users to search
  by service and area, view ratings and prices, and book and pay in one place, providing a unified platform for discovering
  and hiring local service providers. The platform supports multiple languages and integrates with various payment gateways,
  aiming to simplify the process of finding and engaging local expertise.
url: https://artifacts.apis.io/53on-com/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-31 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-31'
modified: '2026-10-31'
tags:
- Marketplace
- Directory
- Local Business
- Services
- Consumer
- Company
tags_raw:
- Marketplace
- Directory
- LocalBusiness
- Services
- B2C
- Company
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgenticAccess
  url: agentic-access/53on-com-agentic-access.yml
- type: Spectral
  url: rules/53on-com-rules.yml
- type: ErrorCatalog
  url: errors/53on-com-problem-types.yml
- type: Conformance
  url: conformance/53on-com-conformance.yml
- type: LLMsTxt
  url: llms/53on-com-llms.txt
- type: AgentCard
  url: a2a/53on-com-a2a.yml
- type: ToolCrosswalk
  url: mcp/53on-com-tool-crosswalk.yml
- type: MCPServer
  url: mcp/53on-com-mcp.yml
- type: WellKnown
  url: well-known/53on-com-well-known.yml
- type: Hosts
  url: hosts/53on-com-hosts.yml
- type: Vendors
  url: vendors/53on-com-vendors.yml
- type: DomainSecurity
  url: security/53on-com-domain-security.yml
- type: Website
  url: https://53on.com/
apis:
- aid: 53on-com:53on-com-s-service-api
  name: 53ON S {service} API
  description: The S {service} API from 53ON — 1 operation(s) for s {service}.
  humanURL: https://53on.com
  baseURL: https://53on.com
  tags: []
  tags_raw:
  - S {service}
  properties:
  - type: OpenAPI
    url: openapi/53on-com-s-service-api-openapi.yml
- aid: 53on-com:53on-com-xsite-api
  name: 53ON Xsite API
  description: The Xsite API from 53ON — 2 operation(s) for xsite.
  humanURL: https://53on.com
  baseURL: https://53on.com
  tags:
  - Xsite
  properties:
  - type: OpenAPI
    url: openapi/53on-com-xsite-api-openapi.yml
x-enrichment:
  date: '2026-10-31'
  status: enriched
  artifacts_added: 19
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

53ON API — frequently asked questions

Does 53ON have an API?

Yes. APIs.io lists 2 APIs from 53ON, including 53ON S {service} API and 53ON Xsite API.

Is there an OpenAPI specification for the 53ON API?

Yes. APIs.io indexes 2 OpenAPI specifications for 53ON, each linked for download from this page.

Does 53ON have an MCP server?

Yes. APIs.io lists 1 MCP server for 53ON: Remote MCP server at 53on.com.

Is the 53ON API ready for AI agents?

53ON has a Kin Score of 19.8 out of 100 (emerging) and an Agent Readiness score of 29.1 (agent-ready), scored by API Evangelist on 2026-11-02.

Work with this as data

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Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
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.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

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