Plain website screenshot

Plain

Plain is an API-first customer support platform built around a single GraphQL API. Everything in the product - customers, threads, timeline entries, messages, labels, tiers, and webhooks - is exposed through the same GraphQL endpoint the Plain UI consumes, letting teams build support into their own products with threads, customer context, and a unified timeline.

Plain publishes 1 API on the APIs.io network: GraphQL API. Tagged areas include Customer Support, Help Desk, GraphQL, Threads, and Customer Communication.

Plain’s developer surface includes authentication, documentation, engineering blog, and 8 more developer resources.

🌐 Visit website 📡 Source on GitHub
40.3/100 thin ▬ flat Agent 37/100 agent ready Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessFreemiumOpenFree trial⚡ Free to try
1 APIs
Customer SupportHelp DeskGraphQLThreadsCustomer CommunicationAPI First

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 40.3/100 · thin
Contract Quality 16.4 / 25
Developer Ergonomics 4.3 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 4.8 / 13
Governance 0.0 / 12
Discoverability 6.9 / 10
Agent readiness — 37/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 7 / 7
Rate-Limit Signaling 7 / 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
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/plain-support: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 1

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

Plain GraphQL API

The GraphQL API from Plain — 1 operation(s) for graphql.

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Plain GraphQL API

OPEN COLLECTION

GraphQL 1

GraphQL schemas published by this provider.

Plain GraphQL API

Representative GraphQL schema for the [Plain](https://www.plain.com/) API-first customer

GRAPHQL

Pricing Plans 1

Published pricing tiers and plan structures.

Plain Support Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Plain Support Rate Limits

3 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Plain Support Finops

FINOPS

Security Posture 2

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

Plain Support Authentication

http · 1 scheme

SECURITY

Plain Support Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Plain Support Agentic Access

1 operation · 1 acting

1 operations · 1 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits
RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans
Plans
 FinOps
FinOps

Company 3

The organization behind the API

LinkedIn
LinkedIn
 Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: plain-support
url: https://raw.githubusercontent.com/api-evangelist/plain-support/refs/heads/main/apis.yml
name: Plain
kind: company
description: Plain is an API-first customer support platform built around a single GraphQL API. Everything in the product
  - customers, threads, timeline entries, messages, labels, tiers, and webhooks - is exposed through the same GraphQL endpoint
  the Plain UI consumes, letting teams build support into their own products with threads, customer context, and a unified
  timeline.
accessModel:
  pricing: freemium
  onboarding: open
  trial: true
  try_now: true
  public: true
  label: Freemium (free trial) · Open access
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/plain-support.png
tags:
- Customer Support
- Help Desk
- GraphQL
- Threads
- Customer Communication
- API First
created: '2026-06-20'
modified: '2026-06-20'
specificationVersion: '0.19'
apis:
- aid: plain-support:plain-support-graphql-api
  name: Plain GraphQL API
  description: The GraphQL API from Plain — 1 operation(s) for graphql.
  humanURL: https://www.plain.com/docs/api-reference/graphql/customers/upserting-customers
  baseURL: https://core-api.uk.plain.com/graphql/v1
  tags:
  - GraphQL
  properties:
  - type: OpenAPI
    url: openapi/plain-support-graphql-api-openapi.yml
  - type: GraphQL
    url: graphql/plain-support-graphql.md
  - type: Documentation
    url: https://www.plain.com/docs/api-reference/graphql/customers/upserting-customers
  - type: APIReference
    url: https://www.plain.com/docs/api-reference/graphql/introduction
  - type: Documentation
    url: https://www.plain.com/docs/api-reference/graphql/threads/create-threads
  - type: Documentation
    url: https://www.plain.com/docs/api-reference/graphql/events/create-a-thread-event
  - type: Documentation
    url: https://www.plain.com/docs/api-reference/graphql/messages/reply-to-threads
  - type: Documentation
    url: https://www.plain.com/docs/api-reference/graphql/labels/add-labels
  - type: Documentation
    url: https://www.plain.com/docs/api-reference/graphql/webhooks/create-a-webhook-target
common:
- type: AgenticAccess
  url: agentic-access/plain-support-agentic-access.yml
- type: DomainSecurity
  url: security/plain-support-domain-security.yml
- type: Authentication
  url: authentication/plain-support-authentication.yml
- type: GitHubOrganization
  url: https://github.com/team-plain
- type: LinkedIn
  url: https://www.linkedin.com/company/plain-support
- type: Website
  url: https://www.plain.com
- type: Documentation
  url: https://www.plain.com/docs
- type: Plans
  url: plans/plain-support-plans-pricing.yml
- type: RateLimits
  url: rate-limits/plain-support-rate-limits.yml
- type: FinOps
  url: finops/plain-support-finops.yml
- url: https://www.plain.com/blog
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com