setup_delegation

Start the spending-delegation ceremony and return one URL for a human to open. Use it when pay_service returns { "error": "no_delegation" }. It sets up a stablecoin (crypto) delegation that spends from the human’s personal wallet — it does not enroll a card. The human sets the currency, cap, duration, and transaction limit in the browser; the agent cannot set them and must not ask the human to pass them back. Needs a credential. Auth: key / grant · Charges: nothing

Arguments

Argument	Required	Type	Description
`returnUrl`	no	string	Where the browser lands after authorising. Only a localhost callback (`http://127.0.0.1:<port>/…`) or an origin this deployment allow-lists is accepted; a rejected value is reported, not silently dropped. Omit it unless you actually have somewhere to receive the redirect — in a chat host the page just shows a confirmation and the human closes the tab.

Returns

A URL to open, or confirmation a budget already exists:

{
  "status": "human_action_required",
  "url": "https://embed.nevermined.app/cards/delegate?provider=crypto&network=live&sessionToken=…",
  "expiresAt": "2026-10-02T14:00:00.000Z",
  "instructions": "Relay the url, wait for the human to confirm, then call pay_service again."
}

{
  "status": "already_active",
  "delegationId": "121b880a-…",
  "budget": { "capCents": "500", "spentCents": "8", "remainingCents": "492", "currency": "usdc", "expiresAt": "2026-10-02T13:29:31.691Z" },
  "source": "oauth_grant",
  "message": "Your spending budget is in place: cap 5.00 USDC, 0.08 USDC spent, 4.92 USDC remaining.",
  "instructions": "No human action is needed now. Call pay_service; it spends from this budget by default."
}

already_active means a usable budget is in place (for an OAuth caller, the grant approved on the consent screen) — relay message as it stands, then call pay_service.
budget carries only the figures the API reported, and is omitted when none did. source (oauth_grant or account) is omitted when unknown. message and instructions are always present.

The url embeds a short-lived session token bound to the human’s account. Treat it as a credential — give it only to the account owner, never share it.

Other outcomes (no URL): delegation_setup_unavailable (this deployment can’t run the ceremony), delegation_setup_failed (the session couldn’t start), return_url_not_allowed (drop or fix returnUrl), and a human_action_required answer with delegationCheck: "failed" (an existing budget couldn’t be ruled out — follow its instructions and try pay_service first).

Try it

Ask your assistant:

Set up a spending budget so I can pay for Nevermined services.

Call it directly (charges nothing — returns a URL for a human to approve a cap):

curl -X POST https://mcp.live.nevermined.app/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "Authorization: Bearer $NVM_API_KEY" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"setup_delegation","arguments":{}}}'

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Arguments

Returns

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​Arguments

​Returns

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Arguments

Returns

Try it