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A Dify app will be able to browse the Nevermined Catalog and pay for services with a plain Nevermined API key. This page covers the funding you can set up now and the connector that’s on the way; for the full tool surface and the safety model, see Using the Catalog from a harness.
Dify connects with a plain Nevermined API key, not the OAuth “approve a spending cap” flow that some assistants (Claude, ChatGPT) use. The key is your credential — it spends whatever its Nevermined account funds, so you set the budget on your account, not in Dify.
The connector is on the way. Dify’s built-in Add MCP Server (HTTP) flow authenticates with OAuth only (Dynamic Client Registration, or a manual Client ID + Secret) — it has no field for a plain API-key header, which is how the Catalog accepts these hosts. So you can’t yet add the Catalog through Dify’s native connector. A Nevermined Dify Marketplace plugin that carries the key is in progress; until it lands, drive the Catalog from your own code or another host — see Using the Catalog from a harness.

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Before you connect

1

A Nevermined account

Free, at nevermined.app.
2

A Nevermined API key

Create a plain API key in the app — Settings → Global NVM API Keys — for the environment you want, and send the whole string, prefix included (sandbox:… or live:…). A key minted by an OAuth flow can’t pay through the Router’s delegation routes, so use a plain one. See Get a Nevermined API key.
3

A way to pay

The key spends from one of two budgets you set up once: a Nevermined Subscription whose monthly credits a plain key can spend, or a spending delegation — a capped, revocable budget funded from your own wallet (Using the Catalog from a harness walks through it). Discovery is free and needs neither.
Start on sandbox, where you use testnet funds and nothing costs real money, before you point Dify at live.

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Add the Catalog to Dify

The Catalog will connect through the Nevermined Dify Marketplace plugin (in progress — see the warning above), because Dify’s built-in MCP connector authenticates with OAuth only and the Catalog uses a plain API-key header for these hosts. When the plugin is published, this section becomes: add it from the Dify Marketplace and paste your Nevermined API key. The server URLs the plugin will point at: In the meantime, your Nevermined account and funding are already usable from any host that accepts an API-key header, or from your own code — see Using the Catalog from a harness.

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Your Nevermined API key

That key is your credential — there is no separate consent screen to approve. Keep the prefix: a live: key for mcp.live, a sandbox: key for mcp.sandbox. The key spends whatever its account funds — your Subscription credits, or a spending delegation funded from your wallet — so the budget and the audit trail live on your Nevermined account, not in Dify. Treat it like a password: never commit it or paste it into a shared chat. Every way to mint one: Get a Nevermined API key.

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Make your first paid call

Once the plugin is connected, give your Dify app a task that needs a live, paid service, so it reaches for the Catalog tools rather than answering from memory.
1

Browse for free

Have the app call a free discovery tool first — list the Nevermined catalog categories, or search the catalog for a weather service. Discovery needs no payment.
2

Let it buy

Then have it pay a service by slug — buy the service <slug> and return the response. The paid call draws on your subscription credits or delegation and returns the merchant’s response.
If the app answers without paying, it answered from its own knowledge — have it call a discovery tool first and ask for something only live data can answer. More on phrasing: Catalog MCP tips.

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Disconnect or rotate the key

  • Stop the credential (Nevermined side). The key is the credential, so to cut Dify off, rotate or delete the key in the app (Settings → Global NVM API Keys) — every call with the old key then fails. To cap spending without revoking the key, revoke the delegation it spends from in Payment methods; discovery still works.
  • Remove the server (Dify side). Once the plugin is installed, remove it from your Dify app’s tools.
To spend again, paste a fresh key; if you revoked the delegation, create a new one — see Using the Catalog from a harness.

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Next

Using the Catalog from a harness

The full plain-key playbook — discovery, delegations, and the safety rules.

Catalog MCP — full reference

Every tool, the API-key header, and every refusal code.