SMS Assist

SMS Assist (rebranded as Lessen) is a facilities maintenance, repair, and work-order management company. Its "One" Platform coordinates reactive and recurrent maintenance, turn/renovation projects, invoices, proposals, assets, and a nationwide vendor network for residential and commercial properties. Lessen exposes the platform through the One Open API v2 — a GraphQL API split into a Client surface (property owners/managers create and track work orders, residents, locations, invoices, and Turn/Reno projects) and a Vendor surface (affiliate technicians manage assets, communications, and work orders) — plus a rich webhook event catalog, SSO/SCIM provisioning, and isolated sandbox and production environments. The legacy REST Open API v1 and Affiliate API v1 were sunset in favor of the v2 GraphQL platform.

SMS Assist publishes 2 APIs on the APIs.io network. Tagged areas include Company, Facilities Management, Property Maintenance, Work Orders, and Field Service.

The SMS Assist catalog on APIs.io includes 1 event-driven AsyncAPI specification.

SMS Assist’s developer surface includes documentation, API reference, getting-started guide, authentication, signup flow, engineering blog, changelog, and 20 more developer resources.

🌐 Visit website 📡 Source on GitHub

44.4/100 developing ▬ flat Agent 24/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessSelf serve

2 APIs

Company Facilities ManagementProperty MaintenanceWork Orders Field Service Maintenance Real-Estate GraphQL WebhookVendor Network

Kin Score

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

Composite quality — 44.4/100 · developing

Contract Quality 10.4 / 25

Developer Ergonomics 12.3 / 20

Access Clarity 6.8 / 20

Operational Transparency 5.1 / 13

Contract Governance 2.2 / 12

Discoverability 7.6 / 10

Agent readiness — 24/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 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/sms-assist: 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 →

APIs 2

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

One Open API v2 - Client

GraphQL API for clients (property owners and managers) to create and track reactive and recurrent work orders, residents, locations, service requests, invoices, proposals, Turn/...

One Open API v2 - Vendor

GraphQL/HTTP API for vendors and affiliate technicians to manage assets (service and location assets), attachments, communications and messages, client lists, employees, locatio...

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Sms Assist Webhooks

ASYNCAPI

Security Posture 2

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

Sms Assist Authentication

http/oauth2 · 2 schemes

SECURITY

Sms Assist Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 5

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Login

Sandbox

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

X-MCPServerCandidate

AgentSkill

LLMsTxt

WellKnown

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Webhooks

Lifecycle

Conventions

ErrorCatalog

Conformance

DataModel

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 4

Status, limits, changes, and where to get help

StatusPage

ChangeLog

ChangeLog

Deprecation

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: sms-assist
name: SMS Assist
description: SMS Assist (rebranded as Lessen) is a facilities maintenance, repair, and work-order management company. Its
  "One" Platform coordinates reactive and recurrent maintenance, turn/renovation projects, invoices, proposals, assets, and
  a nationwide vendor network for residential and commercial properties. Lessen exposes the platform through the One Open
  API v2 — a GraphQL API split into a Client surface (property owners/managers create and track work orders, residents, locations,
  invoices, and Turn/Reno projects) and a Vendor surface (affiliate technicians manage assets, communications, and work orders)
  — plus a rich webhook event catalog, SSO/SCIM provisioning, and isolated sandbox and production environments. The legacy
  REST Open API v1 and Affiliate API v1 were sunset in favor of the v2 GraphQL platform.
url: https://raw.githubusercontent.com/api-evangelist/sms-assist/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- insight-partners
x-tier: stub
x-tier-reason: portfolio-lead
x-rebrand: Lessen (www.lessen.com)
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-21'
image: https://assets-global.website-files.com/650de1047e0c5de5860e054c/656a1bd286bfe157a42e4b53_brand-logo-global.svg
tags:
- Company
- Facilities Management
- Property Maintenance
- Work Orders
- Field Service
- Maintenance
- Real-Estate
- GraphQL
- Webhook
- Vendor Network
tags_raw:
- Company
- Facilities Management
- Property Maintenance
- Work Orders
- Field Service
- Maintenance
- Real Estate
- GraphQL
- Webhooks
- Vendor Network
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- name: One Open API v2 - Client
  description: 'GraphQL API for clients (property owners and managers) to create and track reactive and recurrent work orders,
    residents, locations, service requests, invoices, proposals, Turn/Reno projects, ratings, and attachments across the Lessen
    One Platform. Authentication is token-based: obtain a bearer access_token from the /one-graph-client/token endpoint via
    HTTP Basic Auth.'
  humanURL: https://developers.lessen.com/docs/#/client/overview
  baseURL: https://meshlive.lessen.com/one-graph-client/graphql
  properties:
  - type: GraphQL
    url: https://meshlive.lessen.com/one-graph-client/graphql
  - type: Documentation
    url: https://developers.lessen.com/docs/#/client/overview
  - type: Sandbox
    url: https://meshstage.lessen.com/one-graph-client/graphql
  - type: Console
    url: https://meshstage.lessen.com/one-graph-client/ui/graphiql
- name: One Open API v2 - Vendor
  description: GraphQL/HTTP API for vendors and affiliate technicians to manage assets (service and location assets), attachments,
    communications and messages, client lists, employees, locations, reactive and recurrent work orders, and invoices on the
    Lessen One Platform. Token-based auth via the /one-graph-vendor/token endpoint (HTTP Basic Auth to a bearer access_token).
  humanURL: https://developers.lessen.com/docs/#/vendor/overview
  baseURL: https://meshlive.lessen.com/one-graph-vendor/graphql
  properties:
  - type: GraphQL
    url: https://meshlive.lessen.com/one-graph-vendor/graphql
  - type: Documentation
    url: https://developers.lessen.com/docs/#/vendor/overview
  - type: Sandbox
    url: https://meshstage.lessen.com/one-graph-vendor/graphql
common:
- type: DomainSecurity
  url: security/sms-assist-domain-security.yml
- type: Website
  url: https://www.lessen.com/
- type: DeveloperPortal
  url: https://developers.lessen.com/
- type: Documentation
  url: https://developers.lessen.com/docs/
- type: APIReference
  url: https://developers.lessen.com/docs/#/client/overview
- type: GettingStarted
  url: https://developers.lessen.com/docs/#/client/overview
- type: Authentication
  url: authentication/sms-assist-authentication.yml
- type: SignUp
  url: https://developers.lessen.com/login
- type: Login
  url: https://developers.lessen.com/login
- type: Blog
  url: https://www.lessen.com/resources
- type: TermsOfService
  url: https://www.lessen.com/legal/terms-of-use
- type: PrivacyPolicy
  url: https://www.lessen.com/legal/privacy-policy
- type: StatusPage
  url: https://status.lessen.com/
- type: ChangeLog
  url: https://developers.lessen.com/docs/#/client/releaseNotes/client
- type: ChangeLog
  url: changelog/sms-assist-changelog.yml
- type: Deprecation
  url: https://developers.lessen.com/docs/#/vendor/overview
- type: Webhooks
  url: https://developers.lessen.com/docs/#/client/guides/webhook/about-webhooks
- type: Lifecycle
  url: lifecycle/sms-assist-lifecycle.yml
- type: Conventions
  url: conventions/sms-assist-conventions.yml
- type: Sandbox
  url: sandbox/sms-assist-sandbox.yml
- type: ErrorCatalog
  url: errors/sms-assist-problem-types.yml
- type: X-MCPServerCandidate
  url: mcp/sms-assist-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/sms-assist-llms.txt
- type: WellKnown
  url: well-known/sms-assist-well-known.yml
- type: Conformance
  url: conformance/sms-assist-conformance.yml
- type: DataModel
  url: data-model/sms-assist-data-model.yml
x-enrichment:
  date: '2026-07-21'
  status: enriched
  artifacts_added: 18
  pass: local-v1

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