Plain

Plain is a customer support platform for B2B and technical SaaS companies, built entirely on its own public GraphQL API so there is full parity between what the product UI and the API can do. It unifies support across email, chat, Slack, and API-created threads, with customers, companies, tenants, tiers and SLAs, labels, help center articles, snippets, tasks, and events as first-class entities. Developers integrate via a Relay-style GraphQL API (bearer API keys with fine-grained permissions), typed TypeScript and Go SDKs, a CLI, customer-card UI components, HMAC-signed webhooks, a hosted MCP server, and an official agent skill. This profile was enriched from Plain's public developer surface.

Plain is listed with 1 API on the APIs.io network. Tagged areas include Company, Customer Service, Help Desk, Support, and Software-as-a-Service.

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

Plain’s developer surface includes documentation, API reference, getting-started guide, engineering blog, support, pricing, changelog, and 26 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

61.2/100 strong ▬ flat Agent 51/100 agent ready Front door AI 5/6 prominent Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessPaid

1 API 1 MCP Servers 1 Agent Skills

Company Customer Service Help Desk Support Software-as-a-Service GraphQL Webhook MCP Developer Tools

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 61.2/100 · strong

Contract Quality 10.8 / 21

Developer Ergonomics 13.4 / 17

Access Clarity 14.5 / 17

Operational Transparency 4.7 / 11

Contract Governance 0.5 / 10

Discoverability 6.4 / 9

Regulatory Posture 4.4 / 15

Agent readiness — 51/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 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 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 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):

Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
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)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
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
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too

4 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 51.0 — up to +12.3 composite points
Contract Governance scores 4.5 — up to +11.5 composite points
Operational Transparency scores 42.1 — up to +7.5 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/plain/apis.yml: open an issue on github.com/api-evangelist/plain 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 →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Customer Support, Helpdesk and Contact Center	standard	38.9	-	1
Agent Skills (SKILL.md packages)	standard	38.9	-	1

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 5

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.

GraphQL

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

Model Context Protocol (MCP)

measured — observed by APIs.io (verified)

Agent Skills

measured — observed by APIs.io (published)

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

Dynamic Client Registration

measured — observed by APIs.io (published)

APIs 1

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

Plain Core GraphQL API

Plain's Core GraphQL API — the same API the Plain product is built on. Manage customers, companies, tenants, threads, messaging, help center, labels, tiers/SLAs, snippets, tasks...

MCP Servers 1

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

Plain MCP Server

Remote MCP server at mcp.plain.com over HTTP; 30 tools listed.

MCP SERVER

Agent Skills 1

Packaged agent skills for driving this provider's APIs from an AI assistant.

plain-support

AGENT SKILL

Plain API pricing

Prices published by Plain, read 2026-10-28 from www.plain.com/pricing.

Plan	Price
Foundation	$45/user/month billed annually Includes: 1,000 credits / month; Member seats up to 5; Viewer seats unlimited
Horizon	$99/user/month billed annually Includes: 2,500 credits / month; Member seats minimum 3, up to 10
Frontier	Custom Includes: Custom credits; Custom member seats

Plan details, limits and sources →

Billed by: user · FinOps profile →

Pricing Plans 2

Published pricing tiers and plan structures.

Plain Plans Pricing

3 plans

PLANS

Plain Price Estimates

0 plans

PLANS

FinOps 1

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

Plain Finops

FINOPS

Event Specifications 1

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

Plain Webhooks

ASYNCAPI

Security Posture 3

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

Plain Authentication

apiKey/oauth2/mutualTLS · 4 schemes

SECURITY

Plain Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Plain Trust Center

trust center published

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Login

Documentation 3

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

GraphQL

GraphQL

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

MCPServer

MCPServer

AgentSkill

AgentSkill

LLMsTxt

LLMsTxt

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

Lifecycle

Conformance

DataModel

Components

Webhooks

Scroll for all 7

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

Packages

SDKs

CLI

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

TrustCenter

TrustCenter

Operate 4

Status, limits, changes, and where to get help

Support

StatusPage

ChangeLog

ChangeLog

Commercial 4

Pricing, plans, and the legal terms of use

Plans

Pricing

TermsOfService

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: plain
name: Plain
description: Plain is a customer support platform for B2B and technical SaaS companies, built entirely on its own public GraphQL
  API so there is full parity between what the product UI and the API can do. It unifies support across email, chat, Slack,
  and API-created threads, with customers, companies, tenants, tiers and SLAs, labels, help center articles, snippets, tasks,
  and events as first-class entities. Developers integrate via a Relay-style GraphQL API (bearer API keys with fine-grained
  permissions), typed TypeScript and Go SDKs, a CLI, customer-card UI components, HMAC-signed webhooks, a hosted MCP server,
  and an official agent skill. This profile was enriched from Plain's public developer surface.
url: https://raw.githubusercontent.com/api-evangelist/plain/refs/heads/main/apis.yml
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: paid
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Paid
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-06'
  method: derived
image: https://framerusercontent.com/assets/8LkFDsA5X0pauVd2p3tTSJ4AF4s.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- battery-ventures
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Customer Service
- Help Desk
- Support
- Software-as-a-Service
- GraphQL
- Webhook
- MCP
- Developer Tools
tags_raw:
- Company
- Customer Support
- Customer Service
- Help Desk
- Support
- SaaS
- GraphQL
- Webhooks
- MCP
- Developer Tools
- Customer-Support
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- name: Plain Core GraphQL API
  description: Plain's Core GraphQL API — the same API the Plain product is built on. Manage customers, companies, tenants,
    threads, messaging, help center, labels, tiers/SLAs, snippets, tasks, events, and webhook targets.
  humanURL: https://www.plain.com/docs/api-reference
  baseURL: https://core-api.uk.plain.com/graphql/v1
  properties:
  - type: GraphQL
    url: graphql/plain-schema.graphql
  - type: Documentation
    url: https://www.plain.com/docs
  - type: APIReference
    url: https://www.plain.com/docs/api-reference
  - type: Authentication
    url: authentication/plain-authentication.yml
common:
- type: Plans
  url: plans/plain-plans-pricing.yml
- type: Website
  url: https://www.plain.com/
- type: DomainSecurity
  url: security/plain-domain-security.yml
- type: DeveloperPortal
  url: https://www.plain.com/docs
- type: Documentation
  url: https://www.plain.com/docs
- type: APIReference
  url: https://www.plain.com/docs/api-reference
- type: GettingStarted
  url: https://www.plain.com/docs/graphql/introduction
- type: GitHubOrganization
  url: https://github.com/team-plain
- type: Blog
  url: https://www.plain.com/blog
- type: Support
  url: https://help.plain.com
- type: Pricing
  url: https://www.plain.com/pricing
- type: Login
  url: https://app.plain.com
- type: TermsOfService
  url: https://www.plain.com/legal/terms-and-conditions
- type: PrivacyPolicy
  url: https://www.plain.com/legal/privacy-policy
- type: StatusPage
  url: https://status.plain.com
- type: ChangeLog
  url: https://www.plain.com/changelog
- type: ChangeLog
  url: changelog/plain-changelog.yml
- type: GraphQL
  url: graphql/plain-schema.graphql
- type: Authentication
  url: authentication/plain-authentication.yml
- type: Conventions
  url: conventions/plain-conventions.yml
- type: ErrorCatalog
  url: errors/plain-error-codes.yml
- type: Lifecycle
  url: lifecycle/plain-lifecycle.yml
- type: Conformance
  url: conformance/plain-conformance.yml
- type: DataModel
  url: data-model/plain-data-model.yml
- type: Packages
  url: packages/plain-packages.yml
- type: SDKs
  url: packages/plain-packages.yml
- type: CLI
  url: cli/plain-cli.yml
- type: Components
  url: components/plain-components.yml
- type: MCPServer
  url: mcp/plain-mcp.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Webhooks
  url: asyncapi/plain-webhooks.yml
- type: LLMsTxt
  url: llms/plain-llms.txt
- type: TrustCenter
  url: security/plain-trust-center.yml
x-enrichment:
  date: '2026-07-20'
  status: enriched
  artifacts_added: 18
  pass: local-v1

Plain API — frequently asked questions

Does Plain have an API?

Yes. APIs.io lists 1 API from Plain, including Plain Core GraphQL API.

How do I authenticate with the Plain API?

Plain documents its authentication (apiKey/oauth2/mutualTLS · 4 schemes). The details are profiled on APIs.io as Plain Authentication.

How much does the Plain API cost?

Plain publishes its prices; its Foundation plan is $45/user/month billed annually as of 2026-10-28. APIs.io lists 3 pricing plans for Plain, with each plan's price, limits and inclusions under Pricing on this page.

Does Plain have an MCP server?

Yes. APIs.io lists 1 MCP server for Plain: Remote MCP server at mcp.plain.com over HTTP; 30 tools listed.

Is the Plain API ready for AI agents?

Plain has a Kin Score of 61.2 out of 100 (strong) and an Agent Readiness score of 51.1 (agent-ready), scored by API Evangelist on 2026-11-06.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

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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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