Ship your own partner storefronts. Or hire it out.
Fermat is an agency-style AI commerce service for enterprise brands. Comet is self-serve partner storefronts on Shopify. Both are real; they solve different jobs. Here is how to tell which one fits.
The short version
Fermat is effectively an agency with a SaaS layer. They'll build 3-10 shops a month for you, charge $3,000-$7,000/month, and lock you into an annual contract. Comet is the opposite motion, a Shopify-native product your team, your agency, or your AI agent (Claude Code, Cursor, MCP) operates programmatically, from $49/mo, with unlimited stores and no long-term contract.
If you want done-for-you, Fermat is strong. If you want it done by you or by your agent, with infrastructure that scales across creators, publishers, and campaigns, Comet is the faster call.
Do the math
Fermat Visionary = around $700 per store per month.
That is $7,000/mo for up to 10 shops. If your creator program has 30 creators, you're either paying out-of-plan or splitting the cohort across quarters. Comet's Growth tier is one-twentieth of that cost and has no cap on how many stores live at once.
Fermat's model makes sense when every shop is a bespoke funnel worth four figures to build. It doesn't scale to programs where the store is a routine artifact you need one of per partner.
Side by side
Plainly. No asterisks.
| Dimension | Fermat | Comet |
|---|---|---|
| Model | Agency-style service, Fermat builds and operates shops for you | Self-serve SaaS, you build and operate stores yourself |
| Who builds your stores | Fermat's team (with your input and brand assets) | You, your agency, your AI agent (Claude Code, Cursor, MCP), or our built-in AI Builder |
| Operator interface | Fermat team via ticketed account management | Dashboard, REST API, MCP for agentic workflows |
| Setup time | 90-day onboarding. Fermat builds your first 5 landers. | First store live in 5 minutes |
| Pricing | Scientist: $3k/mo ($2k for first 120 days). Visionary: $7k/mo ($5k for first 120 days). | $49-$499/mo self-serve, Enterprise tier available |
| Store build limit | Scientist: 3 shops/month. Visionary: 10 shops/month. Extra builds are out-of-plan. | Unlimited stores in every paid tier |
| Contract term | Annual lock-in is standard. 90-day opt-out clause. | Monthly. Cancel anytime. |
| Effective cost per store | Scientist around $1,000/store/month. Visionary around $700/store/month. Rises if you need more than the cap. | Growth around $3-5 per store/month at typical partner-program scale. |
| Platforms | Headless / Salesforce Commerce Cloud / custom stacks | Shopify-native (App Store install), SFCC, others on request |
| Channels supported | Paid-media funnels (ad-to-checkout), AI search commerce | Creators, Publishers, Campaigns, AI referrals (private beta) |
| Catalogue source | Shop-by-shop curation, often duplicated per shop | Live-synced to your existing Shopify catalogue, one source of truth |
| Dashboard access | Site visits metered: Scientist gets 60/year, Visionary gets 120/year | Unlimited dashboard access for every seat |
| Ownership | Shops live on Fermat's rails | Stores live on your Shopify, your catalogue, your checkout |
| Company | US, enterprise-backed, serves Glossier, BISSELL, ILIA | EU, 200+ partner stores across DTC beauty, fitness, and creator brands |
Fermat details compiled from public sources and third-party reviews. If you see anything we've got wrong, email us and we'll fix it.
Choose Fermat if
You want an agency to build and run it for you.
- You want an agency to build and run 3-10 high-touch funnels a month for you
- Your budget comfortably supports $36k-$84k/year + annual commitment
- You're on a headless, SFCC, or custom stack (not Shopify)
- Your priority is AI-search commerce built and managed as a service
- You prefer outsourcing to hiring in-house, and you want Fermat's team to operate the program
Genuinely, if this is you, Fermat is a good call. Their team is strong and their enterprise customers get real value. Go talk to them.
Choose Comet if
You want to ship partner stores yourself, fast.
- You're a DTC brand on Shopify, $5M-$50M in revenue
- You need more than 10 partner stores a month, not fewer
- You want to move fast, ship a new store in the time it takes to read this page
- You want stores created programmatically, via API, MCP, or your AI agent (Claude Code, Cursor)
- You want infrastructure your team operates directly, not a service you hire
- You want monthly billing with no annual lock-in
The actual moat
Comet is programmatic. Fermat is a team.
Every Comet store is an object that can be created, branded, and launched by an API call or an MCP command. Fermat's stores are created by an agency who schedules a kickoff.
REST API
Your growth engineer integrates Comet into your internal tools. Create a store the moment a creator signs the contract.
MCP server
Your AI agent, Claude Code, Cursor, a custom workflow, talks to Comet natively. "Spin up 20 creator stores from this CSV" becomes a single prompt.
Dashboard
For the partnerships lead who wants to click, not code. Same primitives, same stores, different interface.
An agency's build capacity is capped by their headcount. A programmatic product's capacity is capped by your imagination.
The frame behind it
Agencies and products solve different jobs, and the best answer depends on what your team is hired to do this year.
An agency is right when the problem is one-off, specialised, and worth premium spend: a flagship paid-media campaign, a migration, a headless overhaul. You buy the team.
A product is right when the job is repeatable and you need to scale it across dozens or hundreds of partners without hiring in proportion: a creator program, a publisher roster, a campaign calendar, an AI-agent channel that's growing every quarter. You buy the infrastructure.
Partner stores fall in the second bucket. You're not launching one, you're launching many. That is why Comet is built the way it is.
Ship your first partner store this afternoon.
If Comet fits, you'll have a live store before you'd even book a Fermat intro call.