Fermat

MCP server · hosted · v0.4.0 · xyz.phase.ai/gateway

Online · tested 2h agoNEW · 4h agoNew version 1h agoSeen in the registry 30m ago

OpenAI-compatible LLM gateway: pay per request with an API key, signed receipt for each call.

What it does

Fermat is an MCP server, a connector that lets an AI assistant use it as a tool. It is hosted: an assistant connects to it over the internet, nothing to install.

No capability identified yet from its description.

Facts come from the Official MCP Registry, as declared by the publisher. Capabilities are matched automatically (low confidence) and are not a test of the tool.

At a glance

Hosted (remote)YES

Local installNO

Live checkOnline · 7 tools

Version0.4.0

PriceNot in the registry

First seen22 Oct 2026

Last checked30m ago

How to connect

As declared in the Official MCP Registry · hosted endpoint tested by Electra Index 2h ago (live check)

Hosted endpoint

https://mcp.fermat.ai.phase.xyz/mcp streamable-http

Required: Authorization (get it from the publisher)

MCP settings (Claude Desktop, Cursor and other MCP clients)

{
  "mcpServers": {
    "fermat": {
      "url": "https://mcp.fermat.ai.phase.xyz/mcp",
      "headers": {
        "Authorization": "<your Authorization>"
      }
    }
  }
}

Replace the values in <angle brackets>.

Live check

Electra Index connected to the hosted endpoint 2h ago

ONLINE Fermat answered an MCP connection on 22 Oct 2026 and introduced itself as phase-ai 0.3.0 (MCP protocol 2025-06-18).

7 tools offered to AI assistants

chat · Run a chat completion on the Phase AI gateway, paid from the Phase API key or the wallet this server uses (free models cost nothing). Returns the answer, actual price, task id for the receipt and usage.
embed · Compute embeddings on the Phase AI gateway (paid from the Phase API key or the wallet).
key · Balance, daily cap and spend of the Phase API key this server pays with (key mode).
list_models · List models of the Phase AI gateway with prices (USD per 1M tokens, fee per call) and layer (flagship | open | class | free).
quote · Get the price ceiling for a chat request without paying (the gateway's 402 quote).
receipt · Fetch the public receipt of a paid request by task id (model, provider, tokens, price, settlement tx, request/response hashes, signatures) and its Merkle proof once the weekly epoch is closed.
session · Saved chat sessions on the Phase AI gateway: create one (returns an id and a shareable /s/<id> link), read its thread, list the wallet's sessions (wallet mode only: signed with the wallet key, no transaction), or delete one. Pass the id as

What "online" means: the server answered an MCP connection at the time of the check. It is not a guarantee of security, quality or continuous uptime. How we test: we open an MCP session and ask for the tool list, as an AI assistant would. We never run a tool and never send a key. Checked every few days. Method

Is this your server? Monitoring Pro: a check every 30 minutes and an email within the hour when it stops answering. $9.99/month.

Facts & evidence

Each fact shows where it was seen and when.

Fact	Value	Evidence	Source	Last confirmed
Version	0.4.0	DECLARED	SRC-001 Official MCP Registry	30m ago
Hosted endpoint	https://mcp.fermat.ai.phase.xyz/mcp	DECLARED	SRC-001 Official MCP Registry	30m ago
Local install (package)	no	DECLARED	SRC-001 Official MCP Registry	30m ago
Remote access (hosted)	yes	DECLARED	SRC-001 Official MCP Registry	30m ago
Website	https://fermat.ai.phase.xyz	DECLARED	SRC-001 Official MCP Registry	30m ago
Registry status	active	DECLARED	SRC-001 Official MCP Registry	30m ago
MCP server	yes	DECLARED	SRC-001 Official MCP Registry	30m ago

Change history

VERSION22 Oct 2026
0.3.0 → 0.4.0
NEW22 Oct 2026
first seen in the index

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Questions about Fermat

How do I connect Fermat?

Use the hosted endpoint https://mcp.fermat.ai.phase.xyz/mcp in your assistant's MCP settings. The exact settings are in "How to connect" above, as declared in the Official MCP Registry.

Does Fermat need an API key or token?

Yes. The registry entry lists a required value: Authorization. Get it from the publisher.

What tools does Fermat offer?

When Electra Index connected on 22 Oct 2026, it listed 7 tools: chat, embed, key, list_models, quote, receipt, session. The full list is in "Live check" above.

Is Fermat online?

Yes. Its hosted endpoint answered an MCP connection from Electra Index 2h ago.