> ## Documentation Index
> Fetch the complete documentation index at: https://docs.jointransfer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Get card details

> Return the assigned card number and expiry to a local Codex agent.

`get_card_details` is available in Transfer's local card-details worker and
optional desktop plugin. It is not a tool on the remote HTTP `/api/mcp` server.
Call it without arguments. The private per-agent connection selects the card;
the agent cannot supply another card ID or owner key.

The result is a JSON object containing:

| Field | Meaning |
| - | - |
| `card_id` | Assigned card identifier. |
| `number` | Actual assigned card number. |
| `expiry_month` | Two-digit month. |
| `expiry_year` | Four-digit year. |
| `expiry` | Combined `MM/YY` value for common checkout fields. |
| `last4` | Card's last four digits. |

No CVC, bank balance, owner wallet or other agent's card is returned. The worker
requests a short-lived checkout token and redeems it once with the same private
agent key. Current card assignment, key and Transfer access are rechecked by the
existing exchange. Failure returns a sanitized error without card data.

## Enter through an existing browser

At the intended authorized merchant checkout, Codex can use the returned values
with its available browser fill tools. The worker does not attach to the browser,
run merchant code or submit a payment. It adds no browser permissions.

This mode deliberately exposes reusable card details to model context, tool
history and browser arguments. Avoid repeating the number in chat or saving it
to files. Transfer cannot enforce companion purchase limits or merchant
restrictions once a number is disclosed. Set real limits at the bank. Revoking
Transfer access stops further retrieval, but only freezing or replacing the bank
card stops use of an existing copy.

If the merchant needs CVC or bank authentication, the owner completes that
directly at the merchant. Retrieval and entry are not payment authorization or
proof of a successful charge.

For card numbers kept outside agent context, use the separate
[browser companion](/guides/browser-checkout) or a trusted token-exchange client.


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