Plain in 10 concepts
Plain has a small set of concepts that connect everything else. If you understand these ten, you can navigate the rest of the documentation, configure Plain confidently, and reason about what happens to a customer message from the moment it arrives to the moment it's resolved.
Read top-to-bottom. Each concept builds on the ones before it.
1. Thread
A thread is a single customer conversation. It's the fundamental unit in Plain. Every email, Slack message, Chat session, contact-form submission, Microsoft Teams message, and Discord question becomes a thread, regardless of where it started.
Threads have a status, a priority, an owner, labels, custom fields, and a timeline of every event that's happened to them. Everything else in Plain (workflows, AI, reporting, integrations) operates on threads.
2. Channel
A channel is where threads come from. Plain supports Slack, Email, Microsoft Teams, Chat, Discord, Contact Forms, Discourse, and the Headless Support Portal.
Each channel converts inbound messages into threads using its own rules. Slack ingests selected channels, Email parses incoming mail, and Chat starts a thread per session. Once the thread exists, the channel it came from becomes a property: your team works the thread without thinking about origin, and replies post back to the original channel.
3. Customer, Company, and Tenant
Plain models the people you support in three layers:
Customer: an individual person. The thread author.
Company: a group of Customers created and matched automatically by domain.
Tenant: the contract or account boundary. Usually mapped to your CRM's Account or Organization object. Often a Tenant maps 1:1 to a Company, but Tenants exist separately because some businesses have multiple Companies under a single contract (or one Company spread across multiple Tenants).
You can enrich threads with account context using Tenant fields (e.g. plan, MRR, account manager) and Customer cards for per-customer attributes.
4. Tier
A Tier is a segment of customers, e.g. Enterprise, SMB, and Self-Serve. Tiers attach to Tenants and Companies, and define what level of service those customers receive.
SLAs, escalation paths, routing rules, and reporting can all branch on Tier, so it's the primary lever for differentiating between customer cohorts.
5. SLAs and business hours
SLAs are response-time targets, typically a first-response time and a next-response time, defined per Tier. Plain tracks them on every thread, warns you before a breach, and can trigger automation when one is at risk.
Business hours control which time windows the SLA clock counts. SLAs respect business hours by default, so weekends and holidays don't burn through your targets.
6. Statuses, priorities, labels, and thread fields
These are the attributes that describe a thread:
Status: Todo: (Needs First Response, Needs Next Response, Investigating, Close the Loop) Snoozed: (Waiting for Customer, Paused for Later), Done, or Ignored. The lifecycle of your customer interaction.
Priority: Urgent, High, Normal, or Low. Independent of SLA.
Labels: Categorical tags you create (e.g. Bug, Billing, Feature Request).
Thread fields: Typed custom fields you define for structured data per thread.
Any of these can drive workflows, routing, assignment, and reporting.
7. Assignment and escalation paths
Assignment is who owns a thread right now. You can assign to a person, to a team (with load-balancing), or leave it unassigned. Escalation paths are pre-defined sequences of people or teams a thread moves through if it isn't resolved in time.
Together they answer the question: who handles this, and what happens if no one does?
8. Workflows
A workflow follows the path of event → conditions → actions. When something happens to a thread (created, replied to, label added, SLA at risk), Plain checks conditions (Tier equals X, channel is Slack, an AI prompt matches) and runs actions (assign to team, set priority, send auto-response, escalate).
Workflows are how you encode your team's playbook so threads route themselves.
9. AI Agents in Plain
Plain ships with three AI agent surfaces:
Ari: a customer-facing AI agent that resolves questions in your Help Center and Chat using your knowledge sources, and hands off to a human when it can't.
Sidekick: a team-facing AI assistant that drafts replies, summarises threads, and helps your agents work faster.
Bring Your Own Agent (BYOA): connect Inkeep, Parahelp, Decimal, Duckie, or any custom agent into Plain.
All AI features draw on your knowledge sources (Help Center articles, public docs, custom URLs) and respect your configured tone of voice.
10. Help Center
Your Help Center is the customer-facing surface that ties together three things:
Knowledge base: published articles, organised into groups.
Ask AI: Ari answering questions in natural language, grounded in your knowledge base.
Customer Inbox: a single place where customers can submit, track, and reply to their support requests across all channels.
You can run multiple Help Centers from one workspace. Typical setups include a public docs site, a customer-only portal, and an internal team knowledge base. They all feed into the same support queue.
Ready to set things up? Continue to the Quickstart for a 30-minute path from sign-up to live, or jump straight into Channels if you already know what you want to connect first.