Assembly, previously named Copilot, is an extensible client portal and back-office platform for professional service firms. Retainr is deliberately narrower and lighter: package expert outcomes, route buyers into the right onboarding, deliver through a branded method, and turn proven work into recurring client revenue without a software subscription.
The right choice depends on the operating constraint you need to remove, not the length of a feature list. Use the two fit profiles below before comparing individual capabilities.
Solo experts and lean specialist teams that want a focused, free system for offers, paid signup, delivery, support, and recurring client relationships.
Tech-enabled professional service firms that need an extensible portal platform, embedded applications, custom integrations, advanced permissions, or enterprise security controls.
These are workflow distinctions based on current first-party product material, not paid placement or crowdsourced ratings.
| Decision area | Retainr | Assembly |
|---|---|---|
| Published software cost | $0. Retainr includes every feature, unlimited team members, unlimited clients, and its white-label client experience free forever. | Assembly publishes Starter from $39/month, Professional from $149/month, Advanced from $399/month, and Enterprise from $2,000/month. Higher tiers add users, limits, and controls. |
| Primary operating model | A guided system for productizing expertise and extending successful client work into recurring revenue. | An extensible client-facing platform combining CRM, portal, billing, contracts, tasks, files, forms, embeds, and apps. |
| Limits and team access | Does not limit team members, clients, or feature access by plan. | Starter lists one internal user and 50 clients; Professional lists three internal users and 500 clients, with additional-user pricing. |
| Branding and extensibility | Includes custom-domain and white-label client delivery around Retainr's built-in service workflow. | Professional adds custom domains, API, Zapier, Make, and custom apps; Advanced lists full white labeling and additional security controls. |
| Ideal complexity | Optimized for a compact expert business that wants fast setup around a few repeatable offers. | Designed to scale into custom apps, advanced client permissions, HIPAA requirements, SSO, and enterprise deployments. |
A polished demo is not evidence that a system fits your daily client work. Use one representative service and complete the real journey.
Can the right buyer understand the outcome, boundary, price, and next step without a call?
Check how much context survives from the selected offer into onboarding and internal work.
Invite a client, share a file, request approval, update progress, and resolve a question.
Test a late payment, scope question, revision, changed deadline, or support request.
Create the next recurring offer, then confirm that client and business data can be exported cleanly.
This page was reviewed on 8 August 2026 using the official sources below. Product names belong to their respective owners. Features, prices, limits, and availability can change, so verify any purchase-critical detail on the vendor's current site.
Yes. The company announced in September 2025 that Copilot had become Assembly. This comparison uses the current Assembly name while acknowledging the former brand for people searching older references.
Retainr is free forever and covers offers, clients, payments, projects, support, portals, and recurring services. Assembly goes further into custom applications, embedded tools, advanced permissions, and enterprise security.
Retainr is the more focused and lower-cost choice for a solo specialist building repeatable client revenue. Assembly is stronger when the solo business specifically needs its extensible portal architecture or custom app ecosystem.
Package one paid outcome, preserve the buyer's context through onboarding, and build the recurring next step into the way you deliver.