# transaction

**Type:** GraphQL subscriptions

**Description:**
Subscribe to a transaction and receive an event when it is included in a block and indexed.

This subscription lets clients listen for a specific transaction by its `requestKey` and be notified
as soon as that transaction is mined, confirmed, and available in the indexer.
It is typically used by wallets, explorers, and dApps to update the transaction status in real time
without polling the API.

You can optionally specify a `chainId` to narrow the search to a single chain.
If omitted, the subscription will look for the transaction across all chains.

⚠️ **Note:** The event is emitted **only once** — when the transaction leaves the mempool and becomes part
of a block that has been indexed.

## Arguments
- chainId (String): (Optional) The chain ID where the transaction is expected to occur.
If omitted, all chains are searched.
- requestKey (String): The request key of the transaction to listen for.
The subscription emits an event once this transaction is confirmed and indexed.

## Response
**Type:** Transaction
**Description:**
Represents a transaction executed on the Kadena blockchain.

A `Transaction` encapsulates the full structure and outcome of a blockchain transaction —
from the original signed command to the resulting execution details.
Each transaction is uniquely identified by its `hash` and includes the submitted command (`cmd`),
associated signatures (`sigs`), and the execution result (`result`).

This type is fundamental for querying and analyzing blockchain activity, tracking execution outcomes,
and verifying signed payloads.

### Fields
- id (ID): Globally unique identifier for this transaction node.
- cmd (TransactionCommand): The original signed transaction command submitted to the network.
Includes metadata, payload, signers, and network information.
- hash (String): The unique hash of the transaction.
This value is derived from the signed command and serves as the canonical identifier
for the transaction on-chain.
- result (TransactionInfo): The result of executing the transaction.
Includes information such as success/failure status, events, continuation data,
and any state changes triggered by execution.
- sigs (TransactionSignature): The list of signatures associated with the transaction.
Each signature proves authorization from a required signer and is used to validate
that the transaction was properly authorized before execution.