Loomal Index vs mcp.so payment infrastructure vs browse index.
mcp.so is a large, browse-only directory of MCP servers for humans. Loomal Index is an agent-queryable index where every listing can take payment. Different audiences, different jobs — and you can use both. Here's the comparison.
mcp.so and Loomal Index both list MCP servers, but they're built for different consumers. mcp.so is a place for people to browse a very large catalog. Loomal Index is a place for agents to query a payment-ready one.
The choice is less 'which directory' and more 'do you need human reach or agent transactions' — and the answer can be both. This page lays out what each does well and exactly where they part ways.
What mcp.so does well
mcp.so indexes 21,000+ MCP servers and presents them for humans to browse and discover. For sheer catalog breadth and human-facing visibility, it's a strong directory — the kind of place a developer scans to see what's out there.
If your goal is awareness among human builders, a presence in a catalog that large has value.
What Loomal Index adds
Loomal Index is machine-readable and payment-ready. Every listing has the SDK integrated and is x402-ready, so an agent can query the index, read a price and a payment endpoint, and call-and-pay in one transaction — in USDC on Base, with a signed receipt. mcp.so is browse-only: there's no price field and no payment layer, so an agent can read about a tool there but can't transact against it.
The moment the consumer is an autonomous agent rather than a human, that gap is the whole story — discovery without payment doesn't let the agent actually use and pay for the tool.
Side by side
Audience: mcp.so is humans browsing; Loomal Index is agents querying. Catalog: mcp.so is far larger (21,000+); Loomal is smaller but every entry is payable. Payment: mcp.so has none; Loomal has x402 on every listing, from $0.01 a call. Discovery mode: mcp.so is browse-and-read; Loomal is query-and-call. Path to revenue: an mcp.so listing earns nothing directly; a Loomal listing earns per call.
They're different layers — visibility versus transactability — not competing versions of the same thing.
The advantage is structural
Building payment into every listing would require mcp.so to mandate SDK integration for every server, which is a different business model — not something a browse directory bolts on. A browse directory's value is that listing is frictionless; a hard SDK requirement is the opposite of frictionless.
So the catalog gap (Loomal has fewer servers) narrows as more builders list, while the payment gap (mcp.so has none) stays open for a browse directory that wants to remain one.
Use both
List on mcp.so for human-facing reach across the largest catalog. List on Loomal Index when you want agents to discover and pay you automatically, with per-call pricing you set and reprice in one field. There's no conflict in doing both — one builds awareness, the other builds revenue.
FAQ
Is Loomal Index just a smaller mcp.so?
No. mcp.so is a browse-only human directory; Loomal Index is an agent-queryable, payment-ready index. The value isn't catalog size — it's that every listing can be discovered and paid by an agent.
Can agents pay through mcp.so?
No — mcp.so has no payment layer. On Loomal Index every listing is x402-ready, so agents pay per call in USDC on Base automatically.
Why is Loomal's catalog smaller?
Because listing requires SDK integration, which is exactly what makes every listing payable. The catalog grows as more builders integrate; the trade is a smaller list where everything can actually transact.
Should I list on both?
Yes. mcp.so for human reach, Loomal Index for agent discovery and monetization. They're complementary.
What does listing on Loomal Index cost?
No monthly platform fee. You set a per-call price from $0.01; Loomal takes a per-call fee on paid calls and you keep the rest.
List on Loomal Index.
Get discovered by agents and paid per call.