Plain

Support built for companies whose customers are engineers and whose tickets arrive in Slack

Plain is an API-first customer support platform for B2B software companies, built around the channels technical customers actually use: shared Slack, Microsoft Teams, and Discord channels alongside email, chat, an in-app portal, and forms. It pairs a customer-facing AI agent (Ari) with an internal copilot (Sidekick), integrates natively with Linear, Jira, and PagerDuty, and exposes a GraphQL API deep enough to build your own support surface on top of.

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Overview

Plain exists because the standard help desk assumes the wrong customer. When your users are developers at other companies, support does not arrive as a web form; it arrives in a shared Slack Connect channel, a Discord server, or a Teams chat, mixed in with product feedback and a bug report that should really be a Linear issue. Plain treats those channels as first-class inboxes rather than as an integration bolted onto an email tool.

The company was founded in 2020 in London by Simon Rohrbach and Matt Vagni, both from Deliveroo, where Rohrbach ran a 40-person design organisation and Vagni built design systems and internal tooling. It raised a $6M seed co-led by Index Ventures and Connect Ventures in 2022 and a $15M Series A led by Battery Ventures in February 2025, and has since opened a San Francisco office. The customer list is a roll call of developer-tools companies: Vercel, Cursor, n8n, Sourcegraph, Raycast, Clerk, Fly.io, Ashby, Granola, Sanity, and Tinybird among others.

Commercially, two things are worth noting. Viewer seats are free and unlimited on every tier, which is the right model for a company where engineers and account managers need to read threads without being support agents. Against that, both AI agents now run on one metered credit allowance: as of the October 2026 pricing page, a customer-facing Ari resolution costs 100 credits and an internal Sidekick task costs 15 to 300 or more depending on effort, out of 1,000 credits a month on Foundation. Plain previously included Ari with no resolution fee, and that is no longer the deal.

Best for

B2B software companies, especially developer-tools and infrastructure startups, whose customers are technical, whose support arrives in shared Slack, Teams, or Discord channels, and who have engineering capacity to use an API-first platform properly.

Not the right fit for

Consumer, ecommerce, or DTC brands; Plain has no meaningful Shopify or order-management story and the channel mix (Slack, Discord, Teams) is wrong for retail customers. Tidio or Crisp fit that shape.
Non-technical support leads buying without engineering support; the platform's advantage is programmability, and a team that will never touch the GraphQL API is paying for capability it cannot use.
Solo founders and very small teams watching every dollar; Foundation is $45 per seat per month billed annually and there is no free plan, which is more per head than most alternatives.
Teams that need voice or telephony; there is no phone channel, native dialer, or call-centre functionality of any kind.
High-volume, low-complexity consumer support where the entire goal is maximum deflection at minimum cost per conversation.

How it works

1
You connect the places customers already talk to you: Slack Connect channels, Microsoft Teams, Discord servers, a support mailbox, an in-app chat widget, a customer portal, and embedded forms. Each becomes a channel feeding one workspace, so a bug reported in a shared Slack channel and an email to support@ land in the same queue with the same customer context attached.
2
Ari, the customer-facing AI agent, triages what arrives: it answers straightforward questions from the knowledge your team has already written, investigates issues, and escalates when confidence is low or the problem is genuinely complex. Behind the human line, Sidekick acts as the copilot, surfacing account context and drafting responses for an agent to edit, and Insights automatically clusters conversations to surface recurring issues rather than waiting for someone to notice a pattern.
3
Engineering escalation is native rather than an afterthought. Workflows route conversations, fire notifications, and create or link Linear and Jira issues and PagerDuty incidents, so the path from 'customer reports it' to 'engineer owns it' does not run through a copy-paste. CRM integrations pull account tier and contract context onto the thread on the Horizon tier and above.
4
The layer that distinguishes Plain from every other option here is the API. A public GraphQL API, an MCP server addressable by AI assistants, and a bring-your-own-agent model for connecting your own LLM mean support can be programmatically extended: build a custom in-product support surface, sync your own account data onto customer cards, or plug your own agent into the queue rather than accepting the vendor's.

Feature breakdown

26 features in 5 modules

Channels

The core thesis: B2B customers talk to you where they already work, not on a ticket form.

Slack as a first-class channel: Shared Slack Connect channels become real support inboxes with assignment, status, and history, rather than an integration that posts notifications into a channel and loses the thread.
Microsoft Teams: Teams channels are supported from the Horizon tier, which is the practical requirement for selling into larger, Microsoft-standardised enterprise accounts.
Discord: Discord community channels are supported on the Frontier tier, covering the developer-community support model that open-source and infrastructure companies actually run.
Email: Standard shared-inbox email handling alongside the messaging channels, so the customers who still write to support@ are not second-class.
In-app chat and portal: An embeddable chat surface and a customer portal where users see their own conversation history, which matters when your buyer expects an audit trail.
Forms: Embedded in-app forms for structured intake, so a bug report arrives with the fields an engineer needs rather than as free text.

AI

Two agents with two roles, and a pricing model that pointedly avoids per-resolution billing.

Ari, the customer-facing agent: Triages incoming requests, investigates issues, and answers from the knowledge your team has already built. Available on every plan, metered at 100 credits per resolution against the plan's monthly allowance.
Confidence-based escalation: Ari handles routine triage and straightforward questions but hands off to humans when confidence is low or the issue is complex, rather than forcing a customer through a bot loop.
Sidekick, the internal copilot: Surfaces context-aware customer information and drafts responses inside Plain for a human to edit and send. This is what consumes the monthly credit allowance.
Auto-labelling and urgency detection: Incoming conversations are classified and prioritised automatically so triage does not depend on someone reading every message in order.
Thread summaries: Long escalated threads are condensed before an agent picks them up, which is the difference between a two-minute and a twenty-minute handoff.
AI suggested responses: Drafted replies grounded in your own documentation and conversation history, available from the Horizon tier.
Bring your own agent: Rather than locking you to Ari, Plain supports connecting your own LLM or agent into the queue, which matters for companies that have already built their own support model.

Workflows and engineering escalation

The path from customer report to engineering ticket, treated as a product feature.

Linear integration: Create and link Linear issues from a conversation and keep status synchronised, which is the single most-used integration among Plain's developer-tools customer base.
Jira integration: Equivalent two-way issue creation and linking for teams standardised on Atlassian rather than Linear.
PagerDuty and incident routing: Workflows can escalate a customer report into an on-call incident, so a production problem reported in Slack reaches the person carrying the pager.
Routing and notification workflows: Rule-based assignment, alerting, and external system calls, configurable in the UI or driven programmatically through the API.
SLAs and escalation paths: Formal response and resolution targets with defined escalation, available from the Horizon tier, which is typically when contractual support commitments start appearing in your own customer agreements.

Developer platform

The reason engineering-led teams pick Plain, and the reason non-technical teams should not.

Public GraphQL API: A documented GraphQL API covering customers, threads, and workspace objects, positioned as rate-limit-free, so you can build custom support surfaces rather than accepting the vendor's UI.
MCP server: A Model Context Protocol endpoint that lets AI assistants query and act on support data, so an internal Claude or similar assistant can work the queue under your permissions.
Customer cards: Pull your own product, billing, and usage data onto the customer profile via API, so an agent sees the account's real state instead of asking the customer for their plan.
Custom workspaces: Frontier-tier configuration of bespoke workspace structures for companies with multiple products or support organisations.

Knowledge and analytics

Self-service content and the reporting layer that tells you what to write next.

Help Center: A hosted, public-facing help site included from the Foundation tier, which also feeds Ari's answers.
Knowledge Base: Internal and customer-facing knowledge management included on every plan, structured as the training corpus for both AI agents.
Insights: Automatic detection of trends and recurring issues across conversations, which converts support volume into a product-feedback signal instead of leaving it as a queue metric.
Free viewer seats: Unlimited read-only seats across all tiers, so engineers, account managers, and founders can follow customer threads without occupying a paid seat. Genuinely unusual and genuinely useful.

Use cases

4 documented

Developer-tools startup supporting customers in Slack Connect

Twenty enterprise customers each have a shared Slack channel. Requests, bugs, and feature asks are indistinguishable, nothing has an owner, and the only record of a promise made in March is a scrollback nobody can find.

Each Slack channel becomes a real inbox with assignment, status, and SLA tracking; Ari triages the routine questions; bugs become Linear issues from the thread; and Insights shows which product area generates the volume.

Head of developer success at a Series A infrastructure company

Support is five people, but fifteen engineers need to see customer threads. Every per-seat help desk charges for all twenty, and buying read-only access is a recurring budget argument.

Free unlimited viewer seats on every tier mean the whole engineering org can follow customer conversations while only the five agents are billed, which is the cost structure the team actually needs.

Support engineer building a custom in-product help surface

The company wants support embedded natively in its own dashboard, with the customer's real usage and billing state attached to every conversation, not a generic widget iframe.

The GraphQL API plus customer cards let the team build the surface themselves and push their own account data onto every thread, which is not possible on a settings-screen-only help desk.

Startup weighing per-resolution AI costs

The team wants an AI agent handling first-line questions but is looking at $0.75 per resolution elsewhere, which turns a successful deflection programme into a growing monthly bill.

Both agents draw on one monthly credit allowance: 100 credits for an Ari resolution, 15 to 300 or more for a Sidekick task. Deflection volume therefore does move the bill, and Foundation's 1,000 credits a month are consumed by roughly ten Ari resolutions.

Pricing

from $45 per user per month billed annually (Foundation, $55 monthly)

Per-seat subscription in three tiers, each with a seat band and a monthly credit allowance that both AI agents draw on. Ari, the customer-facing agent, costs 100 credits per resolution; Sidekick, the internal copilot, costs 15 to 300 or more credits depending on the effort a task takes. Viewer seats are unlimited and free on every plan. Billed annually or monthly, with the annual rate roughly 20% lower and double the included credits.

Plan	Price	Includes
Foundation	$45 per user, per month, billed annually ($55 monthly)	Up to 5 user seats, unlimited viewer seats 1,000 credits a month on annual billing, 500 on monthly Slack (25 channels), 2 email addresses, in-app forms, live chat Ari and Sidekick, AI workflows, up to 5 workflows One knowledge base, one customer inbox, Linear and Jira 7 days of reporting history, customer cards on a 12-hour cache The seat band is a real ceiling: five user seats, and the sixth person moves the team to Horizon regardless of which features it needs.
Horizon	$99 per user, per month, billed annually	Minimum 3 seats, up to 10 2,500 credits a month Microsoft Teams, unlimited Slack channels, 10 email addresses SLAs, business hours, escalation paths, CSAT HubSpot, Attio and Salesforce sync, reporting themes Unlimited workflows, knowledge bases and customer inboxes All-time reporting history, customer cards refreshed in 15 seconds The step from $45 to $99 a seat more than doubles the rate, and a three-seat minimum means the smallest Horizon invoice is $297 a month.
Frontier	Custom quoted, billed annually	Custom seats and custom credit allocation External AI agents: bring your own, at 15 credits per assignment and 15 per discussion 25 email addresses, custom workspaces, custom roles SSO and SCIM, advanced security review, custom contracting Support and uptime SLAs White-glove onboarding and a dedicated customer success manager

Plan

Price

Includes

Foundation

$45

per user, per month, billed annually ($55 monthly)

Up to 5 user seats, unlimited viewer seats
1,000 credits a month on annual billing, 500 on monthly
Slack (25 channels), 2 email addresses, in-app forms, live chat
Ari and Sidekick, AI workflows, up to 5 workflows
One knowledge base, one customer inbox, Linear and Jira
7 days of reporting history, customer cards on a 12-hour cache

The seat band is a real ceiling: five user seats, and the sixth person moves the team to Horizon regardless of which features it needs.

Horizon

$99

per user, per month, billed annually

Minimum 3 seats, up to 10
2,500 credits a month
Microsoft Teams, unlimited Slack channels, 10 email addresses
SLAs, business hours, escalation paths, CSAT
HubSpot, Attio and Salesforce sync, reporting themes
Unlimited workflows, knowledge bases and customer inboxes
All-time reporting history, customer cards refreshed in 15 seconds

The step from $45 to $99 a seat more than doubles the rate, and a three-seat minimum means the smallest Horizon invoice is $297 a month.

Frontier

Custom

quoted, billed annually

Custom seats and custom credit allocation
External AI agents: bring your own, at 15 credits per assignment and 15 per discussion
25 email addresses, custom workspaces, custom roles
SSO and SCIM, advanced security review, custom contracting
Support and uptime SLAs
White-glove onboarding and a dedicated customer success manager

Add-ons

Startup programme discount (50% off): Advertised on the pricing page for eligible early-stage startups, which halves the effective entry rate.

Billing notes

Ari is no longer unmetered. The pricing page now prices a customer-facing resolution at 100 credits, so Foundation's 1,000 annual-billing credits cover about ten Ari resolutions a month before Sidekick has used any, and Horizon's 2,500 cover about twenty-five. Teams that chose Plain because its AI agent carried no resolution fee should re-run the arithmetic.
Sidekick costs 15 to 300 or more credits a task, metered by effort rather than by volume, so two months of identical ticket counts can consume very different allowances.
Annual billing is both cheaper and more generous: Foundation is $45 a seat against $55 monthly, and the monthly plan includes 500 credits a month rather than 1,000.
Seat bands sit on top of seat prices. Foundation stops at 5 user seats, Horizon runs from a 3-seat minimum to 10, and Frontier is the only route past that.
Viewer seats are unlimited and free on every plan, which is the one place Plain is structurally cheaper than per-seat competitors: an engineering team can read every thread without a licence.
The pricing page does not publish a rate for extra credits, what happens when an allowance runs out, or whether unused credits roll over. All three are questions to settle in writing before signing.
Prices are as of October 2026 and are quoted in USD.

Value assessment: Plain repriced in 2026 and the shape of the deal changed with it. Where Foundation was $35 a month for a seat with the AI agent thrown in, it is now $45 per seat per month billed annually with AI metered out of a 1,000-credit allowance, and Horizon doubles that to $99 with a three-seat minimum. Against Help Scout's $25 Standard seat or Chatwoot's $19, Plain is now clearly the premium option on list price, and the credit meter means a successful deflection programme costs more rather than less. What still justifies it for the right buyer: unlimited free viewer seats, so a fifteen-engineer company can pay for five and let everyone read; Slack, Teams and Discord as first-class channels rather than integrations; and a GraphQL API deep enough to build your own support surface. For a five-person developer-tools company whose customers file issues in Slack, that combination has no real substitute and the startup programme's 50% takes the sting out. For a non-technical team doing email support, Plain is now expensive in both dimensions, seat and usage, and the alternatives are better value.

Entry price history

Plans were restructured on 1 October 2026, so the current entry price is not directly comparable with the earlier one.

Checked	Entry price	What happened
1 October 2026	$45	Plain moved from a $35 base price with one seat included to per-user pricing: Foundation is $45 per user per month billed annually ($55 monthly) for up to five seats, and its Ari AI agent is no longer free but draws 100 credits per resolution from the plan's allowance.
22 August 2026	$35	First recorded

Dates are when SaaSTracker checked the vendor’s published pricing, not when the vendor changed it. See the price changes log for movements across the whole database.

Strengths & limitations

Strengths

Slack, Teams, and Discord are treated as genuine support channels with assignment, status, and SLA tracking, which no general-purpose help desk in this set does properly.
Both AI agents run from one credit pool rather than a separate per-resolution invoice line, so AI spend is capped by the allowance you bought instead of accruing unpredictably.
Unlimited free viewer seats let an entire engineering organisation follow customer threads without a per-seat charge, matching how B2B software companies actually work.
The GraphQL API, MCP server, and bring-your-own-agent model make Plain programmable in a way that lets a team build its own support surface rather than living inside the vendor's UI.
Native Linear, Jira, and PagerDuty escalation turns the customer-report-to-engineering-ticket path into a workflow rather than a copy-paste.
Credible customer proof in its target segment: Vercel, Cursor, n8n, Sourcegraph, Raycast, Clerk, Fly.io, and Granola are the exact companies Plain is designed for.
Well funded and focused: $15M Series A led by Battery Ventures in February 2025 following a $6M Index and Connect seed, with a clear thesis rather than a broadening product.

Limitations

Ari stopped being free. The October 2026 pricing page meters a customer-facing resolution at 100 credits, so Foundation's 1,000 monthly credits cover about ten of them, and the pricing page publishes no rate for buying more.
Sidekick credits are metered by effort rather than volume, which makes the variable portion of the bill genuinely hard to forecast month to month.
No voice or telephony of any kind, and no realistic path to phone support.
Wrong shape for consumer and ecommerce support: no order-management story, no Shopify depth, and a channel mix aimed at business customers.
The value is concentrated in the API and the channel model, so a team without engineering involvement pays a premium for capability it will not exercise.
Younger and smaller than the incumbents in this category, with a shorter track record and a smaller support and documentation operation.

Head-to-head comparisons

3 alternatives

Plain vs Help Scout

from $21/user/mo (Standard, billed annually; $25 monthly)

Help Scout is the better buy for a non-technical support team doing high-touch email at lower cost per seat, with fifteen years of stability, SOC 2, and HIPAA behind it. Plain is the better buy when your customers are engineers in shared Slack channels, your escalations belong in Linear, and you want an API rather than a settings screen. The AI economics are closer than they were: Help Scout charges $0.75 per AI resolution, while Plain now meters an Ari resolution at 100 credits against a 1,000-credit monthly allowance on Foundation.

Full Plain vs Help Scout comparison

Plain vs Crisp

from $45/mo flat (Mini, 4 seats included)

Crisp is the cheaper, broader, chat-and-widget-led product with flat workspace pricing and bundled AI credits, aimed at SMB and ecommerce teams. Plain is the narrower, more expensive, developer-focused product with a far stronger API and B2B channel model. If your customers browse a storefront, Crisp; if your customers deploy your SDK and open a Slack Connect channel, Plain, and the price difference will be justified by the escalation workflow alone.

Full Plain vs Crisp comparison

Plain vs Chatwoot

from $0 (Community Edition self-hosted, or cloud Hacker tier); $19 per agent per month for cloud Startups

Both attract technical buyers, but for opposite reasons: Chatwoot's appeal is owning MIT-licensed source you can self-host and modify, while Plain's is a hosted GraphQL API and a channel model built around Slack, Teams, and Discord. Chatwoot's channel mix is consumer web messaging (WhatsApp, Instagram, TikTok) and it is far cheaper per agent; Plain's is business collaboration channels with native Linear and Jira escalation. If your customers message you on WhatsApp, take Chatwoot; if they open a Slack Connect channel and expect a Linear issue back, take Plain.

Full Plain vs Chatwoot comparison

Pairs well with

7 categories

Plain is a support tool, and a team running it still has 7 neighbouring categories to staff. The pick in each is Scribe for product onboarding & PLG, Stunning for retention & churn prevention, TrustPulse for testimonials & social proof, Patreon for community platforms, Courier for notification infrastructure, Heap for product analytics & session replay and Gumroad for subscription billing, each the leading tool in that category on published criteria.

ScribeProduct Onboarding & PLG · Ease of Use
Because
Plain lists wrong shape for consumer and ecommerce support among its limits. Scribe adds per-creator pricing with unlimited readers and no monthly active user meter.
Benefit
New users reach the thing the product is for without a call, and the drop-off shows up in the data.
StunningRetention & Churn Prevention · Ease of Use
Because
Plain is built for support, not retention. Stunning adds lifecycle email and a customer self-service billing portal.
Benefit
Accounts at risk surface while there is still time to call, rather than at renewal.
TrustPulseTestimonials & Social Proof · Ease of Use
Because
Plain lists ari stopped being free among its limits. TrustPulse adds genuine targeting controls including page-level from the entry plan and mobile device.
Benefit
Real customer proof sits on the pages where people decide, not only on a review site.
PatreonCommunity Platforms · Ease of Use
Because
Plain is built for support, not community. Patreon adds broad publishing for free.
Benefit
Customers answer each other in a space the company owns, rather than in a chat nobody can search.
CourierNotification Infrastructure · Ease of Use
Because
Plain is built for support, not notifications. Courier adds strategic investment from Twilio.
Benefit
Product events reach people on the channel they actually read, without building a sender for each one.
HeapProduct Analytics & Session Replay · Ease of Use
Because
Plain is built for support, not product analytics. Heap adds a free plan with 10,000 monthly sessions.
Benefit
Feature usage and drop-off are measurable, so a roadmap argument can end with evidence.
GumroadSubscription Billing · Ease of Use
Because
Plain is built for support, not billing. Gumroad adds built-in audience and email layer.
Benefit
Recurring revenue bills, retries and reconciles itself, including the tax nobody wants to calculate.

Pairings follow the methodology: the leading tool in each complementary category, chosen on published criteria. Placement cannot be purchased.

Full Plain stack

Implementation & onboarding

Setup time: A working workspace with Slack and email connected in an afternoon. Getting real value (workflows routing to Linear, customer cards populated from your own API, Ari trained on your documentation, SLAs configured) is more like two to four weeks with engineering involvement.
Learning curve: Low for agents, moderate to high for the person configuring it. The API-first design means the best implementations involve writing code, and teams that treat Plain as a point-and-click help desk will under-use it. The 7-day trial is short for a proper technical evaluation, so plan the pilot before starting the clock.
Onboarding: Self-serve on Foundation, with Plain's own team assisting on Horizon (including priority Slack support), and a dedicated CSM with white-glove onboarding on Frontier. Eligible early-stage startups can apply to the startup programme for up to 50% off.
Migration notes: Historic conversation import runs through the GraphQL API rather than a one-click migrator, so expect to write a script. The larger migration is conceptual: teams moving from an email-only help desk have to decide which Slack channels become real support inboxes and rebuild their knowledge content so Ari can answer from it, which is content and process work rather than data movement.

Platform, API & security

Platforms: Web appSlack, Microsoft Teams, and Discord integrationsEmbeddable chat and formsCustomer portalGraphQL APIMCP server
API: Public GraphQL API covering customers, threads, and workspace objects, positioned by the vendor as having no rate limits, plus an MCP server that lets AI assistants query and act on support data and a bring-your-own-agent path for connecting your own LLM.
Compliance: GDPR handling as a UK-incorporated operator (Not Just Tickets Ltd)Advanced security controls positioned on the Frontier tier; detailed certification evidence is not published on the marketing pages
Data residency: Not published on public pages; enquire on the Frontier tier.
SSO: SSO and SCIM are Frontier-tier features, not available on Foundation or Horizon.
Security notes: Plain describes enterprise-grade security as an engineering principle and reserves advanced security, SSO, and SCIM for the custom-priced Frontier tier. Buyers needing published certification reports should request them directly rather than rely on public pages.

Support & resources

Channels: In-product and email supportPriority Slack support on HorizonDedicated CSM on Frontier
Documentation: help.plain.com plus developer documentation for the GraphQL API and MCP server; the pricing and credits articles are unusually explicit about how billing works, which is welcome.
Community: Strong presence in the developer-tools and B2B SaaS community through a heavily invested content programme; no large public user forum.

Company

Founded: 2020
Headquarters: London, United Kingdom (with a San Francisco office opened after the 2025 Series A)
Ownership: Venture-backed; operated as Not Just Tickets Ltd
Founders: Simon Rohrbach, Matt Vagni
Employees: Not disclosed; a small team consistent with a recently raised Series A
Funding: $21M raised: a $6M seed in 2022 co-led by Index Ventures and Connect Ventures, and a $15M Series A in February 2025 led by Battery Ventures with Index and Connect participating.

Funding history

Round	Amount	Year	Notes
Seed	$6M	2022	Co-led by Index Ventures and Connect Ventures to build an API-first support platform.
Series A	$15M	2025	Led by Battery Ventures (reported as roughly 14.5M euro and 12M pounds in European coverage); funded a San Francisco office and team expansion.

Timeline

2020Founded in London by Simon Rohrbach and Matt Vagni, both from Deliveroo, where Rohrbach led a 40-person design organisation and Vagni built design systems and internal tooling.
2022Raises a $6M seed co-led by Index Ventures and Connect Ventures to build an API-first customer support platform.
2024Establishes the collaborative B2B support model, treating shared Slack and Discord channels as first-class support inboxes alongside email.
2025Raises a $15M Series A led by Battery Ventures in February, opens a San Francisco office, and grows a customer base concentrated in developer tools: Vercel, Cursor, n8n, Sourcegraph, and Raycast among them.
2026Splits AI into two products, Ari for customers and Sidekick for agents, and ships an MCP server plus a bring-your-own-agent model, keeping Ari free of per-resolution charges while competitors move the other way.

Integrations

Slack and Slack Connect
Microsoft Teams (Horizon)
Discord (Frontier)
Linear
Jira
PagerDuty
CRM integrations (Horizon and above)
GraphQL API and webhooks
MCP server
Bring your own LLM or agent

Frequently asked questions

13 questions

What is Plain?

Plain is an API-first customer support platform for B2B software companies. It treats shared Slack, Microsoft Teams, and Discord channels as first-class support inboxes alongside email, chat, a portal, and forms, and pairs a customer-facing AI agent called Ari with an internal copilot called Sidekick. It is built for teams whose customers are technical and whose escalations belong in Linear or Jira.

How much does Plain cost?

Foundation is $45 per user per month billed annually ($55 monthly) for up to 5 user seats, with 1,000 credits a month on annual billing and 500 on monthly. Horizon is $99 per user per month billed annually, with a 3-seat minimum, a 10-seat ceiling and 2,500 credits. Frontier is custom-priced. Viewer seats are unlimited and free on every plan, there is a 7-day free trial with no credit card, and eligible early-stage startups get 50% off.

Does Plain charge per AI resolution?

It is now, which is a change. Both agents are available on every plan but both consume the same credit allowance: 100 credits for an Ari resolution, 15 to 300 or more for a Sidekick task depending on effort, and 15 credits per assignment plus 15 per discussion for an external agent you bring yourself on Frontier. Allowances are 1,000 credits a month on Foundation with annual billing (500 monthly), 2,500 on Horizon and custom on Frontier. Plain previously included Ari with no resolution fee, so a buyer comparing older reviews will find the economics have moved.

What are Plain's Sidekick credits and how do they work?

Credits meter Sidekick, Plain's internal AI assistant that surfaces context and drafts responses for agents. Each plan includes a monthly allowance that resets at the start of the billing cycle. The important caveat is that credits are consumed by effort rather than by message count, so the same allowance can cover very different amounts of work and the variable part of your bill is harder to forecast than a flat quota would be.

Can Plain handle support in Slack?

Yes, and it is the main reason to choose it. Shared Slack Connect channels become genuine support inboxes with assignment, status, history, and SLA tracking, rather than an integration that posts notifications and loses the thread. Microsoft Teams is supported from the Horizon tier and Discord from Frontier.

Are viewer seats really free in Plain?

Yes. Read-only viewer seats are unlimited and free across all tiers. For a B2B software company where five people answer tickets but fifteen engineers need to follow customer threads, that removes a per-seat cost every competitor in this category charges, and it often makes Plain cheaper in total despite a higher headline seat price.

Who uses Plain?

Plain's customer base is concentrated in developer tools and infrastructure, including Vercel, Cursor, n8n, Sourcegraph, Raycast, Clerk, Fly.io, Ashby, Granola, Sanity, and Tinybird. If your company looks like those, Plain was designed for you; if you sell to consumers, it was not.

Does Plain have an API?

Yes, and it is central rather than peripheral. Plain exposes a public GraphQL API covering customers, threads, and workspace objects (positioned as rate-limit-free), an MCP server so AI assistants can query and act on support data, customer cards for pushing your own product and billing data onto profiles, and a bring-your-own-agent model for connecting your own LLM.

Does Plain support phone or voice?

No. There is no telephony, dialer, or call-centre capability, and no indication one is planned. Plain's channel model is text-based and asynchronous by design, aimed at B2B customers who write rather than call. Teams that need voice as a real channel should look elsewhere or run a separate phone system.

Is Plain worth it for a small startup?

It depends on who your customers are. For a five-person developer-tools company whose users file issues in Slack and whose engineers all need read access, Foundation at $45 a seat plus unlimited free viewer seats plus the 50% startup discount is reasonable and the Linear escalation alone justifies it. For a five-person team doing ordinary email support for non-technical customers, $45 per seat with a 7-day trial, no free plan and AI metered by credits is poor value against Help Scout, Crisp, or Chatwoot.

What should I pair Plain with?

What do I pair with Plain for Product Onboarding & PLG?

Scribe. Plain lists wrong shape for consumer and ecommerce support among its limits. Scribe adds per-creator pricing with unlimited readers and no monthly active user meter.

Is Plain enough on its own?

For support, yes. Plain does not cover retention & churn prevention, testimonials & social proof and community platforms, and its own profile says so; Stunning, TrustPulse and Patreon are the tools that fill those gaps.

Editorial verdict

Plain is the sharpest product in this category for a specific and growing shape of company: B2B software businesses whose customers are engineers, whose support lands in Slack, and whose escalations end in Linear. The channel model is right, the free viewer seats reflect how those teams actually operate, the GraphQL API and MCP server make it programmable rather than merely configurable, and and one credit pool is simpler to govern than a separate AI invoice. The reservations grew in 2026: the entry seat is $45 and Horizon is $99 with a three-seat minimum, Ari went from included to 100 credits a resolution, credits are hard to forecast because Sidekick meters effort rather than volume, there is no voice channel, and there is no free plan. Buy Plain if your customers write to you in a shared Slack channel. If they do not, almost everything here will serve you better and cost less.

Written by the SaaSTracker editorial team. Awards, when shown, are judged against the published criteria in our methodology.

Awards & badges

1 held

Plain holds 1 award from the SaaSTracker editorial program. Badges may be displayed by the vendor; each embed links back to this profile.

Momentum · Customer Support Platforms

“A $15M Series A in February 2025 and a customer list spanning Vercel, Cursor, and Raycast mark Plain as the breakout support desk for developer tools.”

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<a href="https://saastracker.org/products/plain"><img src="https://saastracker.org/badges/embed/plain/momentum-summer-2026.svg?v=2" width="180" height="180" alt="Plain: Momentum, Customer Support Platforms. SaaSTracker Summer 2026 Awards." /></a>

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