Nevermined

You.com allows autonomous agent payments using Nevermined as one option for using x402. It lets an autonomous agent purchase a You.com API key for $5 with a delegated credit card, or top up an existing API key with no human provisioning a key by hand.

The steps below cover getting a Nevermined API key, funding a payment method, and settling a purchase against the plan. The result is a standard You.com API key, valid on every API. Additional information can be found at Nevermined Agentic Instructions.

Each purchase using a Nevermined x402 card-delegation will return a You.com API key or top up the existing token with credits.

Purchase a You.com API Key

$5 is charged to the card used to create the x402 token for each purchase request: POST https://api.you.com/payments/v1/nevermined/purchase-key with the payment-signature header set to your x402 settlement token.

• A successful call returns a real You.com API key:

  1
  {
  2
    "status": "ok",
  3
    "apiKey": "ydc-sk-...",
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    "toppedUp": false
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  }
• A returning payer will top up the existing You.com API key:

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    {
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      "status": "ok",
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      "apiKey": null,
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      "toppedUp": true
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    }
• A replayed token never charges twice, but what it returns depends on the original purchase: replaying a first purchase mints a new key (the original’s plaintext can’t be recovered from cache), while replaying a top-up returns the same apiKey: null response again.
• 402 Payment Required if credentials are missing.

How to Purchase Access as an Autonomous Agent

Agentic Payments are supported by You.com using x402 standards, where the x402 token is used to purchase a You.com API key. A human is only needed the first time—to enroll a payment method and create a Nevermined API key. Everything after that is programmatic and reusable.

1. Get a Nevermined API key (one-time, needs a human) in the Nevermined app. You cannot mint the first key yourself. A human signs in once via the web app:

   • The card owner must register a card at https://nevermined.app.
   • Issue a Nevermined API key to be used by the agent. Store the key and reuse it—send it as Authorization: Bearer <api-key> on every call below.

2. Create a delegation: POST https://api.live.nevermined.app/api/v1/delegation/create with { provider, providerPaymentMethodId, spendingLimitCents, durationSecs, currency }. A delegation authorizes you to spend within a fixed budget and time window—reuse it until it is spent or expires.

3. Mint an x402 access token. For a plain plan top-up there is no protected endpoint to call, so you build the paymentRequired object yourself from the plan ID.

   • POST https://api.live.nevermined.app/api/v1/x402/permissions with { "accepted": { "scheme": "nvm:card-delegation", "network": "stripe", "planId": "<plan>" }, "delegationConfig": { "delegationId": "<your delegation>" } } → returns an accessToken.
   • Build the paymentRequired object—resource.url must be a non-empty URL identifying what you’re buying (for a plan top-up, use the plan’s URL): { "x402Version": 2, "resource": { "url": "<plan-url>" }, "accepts": [{ "scheme": "nvm:card-delegation", "network": "stripe", "planId": "<plan>", "extra": {} }], "extensions": {} }.
   • Do not call POST /x402/settle yourself for this flow. On this paygo plan, settling directly against Nevermined charges the card and hands back a bare settlement receipt—no You.com API key. Send the same token to /purchase-key afterward and you’ve paid twice for one key. /x402/settle and /x402/verify exist for calling a generic Nevermined-metered resource yourself; the You.com purchase flow doesn’t use them.

4. Send the access token to You.com’s purchase endpoint. Skip settling it yourself—send the accessToken from step 3 straight to the /purchase-key endpoint described in “Purchase a You.com API Key” above, in the payment-signature header. That endpoint verifies and settles the token on your behalf and returns the key in one call.

   • Use the returned apiKey the same way as any account-issued key: pass it in the X-API-Key header on Web Search, Contents, Answer, Research, Finance Research requests, and more. See Authentication. Because it’s a standard API key, it works anywhere an account-issued key does.

What Does a You.com API Key Allow Agents to Do?

Pricing for APIs is available at https://you.com/pricing. The paygo plan above redeems for a standard You.com API key, which works on any You.com API including:

Refer to API documentation on how to exercise these endpoints.

• Web Search API: real-time web and news results for grounding LLM responses.
• Contents API: fetches clean HTML or Markdown for a target webpage.
• Answer API: single-call cited answer to a query.
• Research API: multi-step web research with a synthesized, cited answer.
• Finance Research API: the Research API’s multi-step approach over a financial-data index.

Every request goes to https://api.you.com, with the key in the same X-API-Key header regardless of which API you call:

$
curl "https://api.you.com/v1/search?query=nvidia+earnings" \
>
  -H "X-API-Key: $YDC_API_KEY"

What to Do When a Key Is Exhausted?

• HTTP 402, indicating more funds are needed.
• Mint a new Nevermined x402 token using the same Plan ID, and POST to the /purchase-key endpoint to add another $5 of credits to your You.com API key.

Learn More

• Nevermined SDK and API docs
• x402 card delegation