SMS Assist

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)
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: '0.20'
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
- 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: MCPServer
  url: mcp/sms-assist-mcp.yml
- 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