Transactions allow you to group together a number of database operations that must either succeed together or not at all. DefraDB wraps all database operations in transactions by default – you can however also manually start a transaction, enqueue a number of operations in it (ex. create or update a number of documents), and commit or discard it.

## Open transactions {/* #open */}

**CLI:**

Open a new transaction with the CLI command [`defradb client tx new`](/references/cli/defradb_client_tx_new.md). The returned transaction ID is needed for all operations that want to act within this transaction.

```shell title="Example – Open a new transaction"
defradb client tx new
```
```json result
{"id":27}
```

:::tip Expiration
A transaction automatically expires after 60 seconds of inactivity. Tweak the default expiration with the flag `--ttl <seconds>`.
:::

---

**HTTP API:**

Open a new transaction by submitting a `POST` request to the HTTP endpoint [`/tx`](/defradb/references/http/api/new-transaction/). The returned transaction ID is needed for all operations that want to act within this transaction.

```http title="Example &ndash; Open a new transaction"
POST http://localhost:9181/api/v1/tx HTTP/2
accept: application/json
```
```json result
{"id":27}
```

:::tip Expiration
A transaction automatically expires after 60 seconds of inactivity. Tweak the default expiration with the parameter `ttl=<seconds>`.
:::

## Run operations within transactions {/* #queries */}

**CLI:**

Execute database operations (such as creating or altering collections/documents) within a transaction by providing the flag `--tx <id>` to the CLI commands running such operations.

```shell title="Example &ndash; Create a collection and a document within a transaction"
defradb client collection add --tx 27 '
type Book {
  title: String!
  plot: String
  rating: Float
}
'
defradb client query --tx 27 '
mutation {
  add_Book(input:{
    title: "The meaning of it all"
  }) { title }
}
'
```

---

**HTTP API:**

Execute database operations (such as creating or altering collections/documents) within a transaction by providing the extra header `x-defradb-tx: <id>` to the HTTP requests running such operations.

```http title="Example &ndash; Create a collection within a transaction"
POST http://localhost:9181/api/v1/collections HTTP/2
accept: application/json
content-type: text/plain
x-defradb-tx: 27

type Book {
  title: String!
  plot: String
  rating: Float
}
```
```http title="Example &ndash; Create a document within a transaction"
POST http://localhost:9181/api/v1/collections/Book HTTP/2
accept: application/json
content-type: application/json
x-defradb-tx: 27

{
  "title": "The meaning of it all"
}
```

## Commit transactions {/* #commit */}

**CLI:**

Commit a transaction with the CLI command [`defradb client tx commit`](/references/cli/defradb_client_tx_commit.md), providing the ID of an open transaction. All changes get written into memory.

```shell title="Example &ndash; Commit the transaction with ID 27"
defradb client tx commit 27
```

---

**HTTP API:**

Commit a transaction by submitting a `POST` request to the HTTP endpoint [`/tx/:id`](/defradb/references/http/api/new-transaction/), providing the ID of an open transaction as value for `:id`. All changes get written into memory.

```http title="Example &ndash; Commit the transaction with ID 27"
POST http://localhost:9181/api/v1/tx/27 HTTP/2
accept: application/json
```

## Discard transactions {/* #discard */}

**CLI:**

Discard a transaction with the CLI command [`defradb client tx discard`](/references/cli/defradb_client_tx_discard.md), providing the ID of an open transaction. All changes enqueued in the transaction are discarded.

```shell title="Example &ndash; Discard the transaction with ID 27"
defradb client tx discard 27
```

---

**HTTP API:**

Discard a transaction by submitting a `DELETE` request to the HTTP endpoint [`/tx/:id`](/defradb/references/http/api/discard-transaction/), providing the ID of an open transaction as value for `:id`. All changes enqueued in the transaction are discarded.

```http title="Example &ndash; Discard the transaction with ID 27"
DELETE http://localhost:9181/api/v1/tx/27 HTTP/2
accept: application/json
```