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

# Writing data

> Create, update, connect, and remove entities in one typed write batch

<div className="flex flex-wrap gap-2"><Badge color="blue" size="sm">Guide</Badge></div>

Mutations require a write batch. The SDK type prevents a mutating traversal from being
placed in a read batch.

## Create two nodes and an edge

<CodeGroup>
  ```rust Rust theme={"languages":{"custom":["languages/helixql.json"]}}
  write_batch()
      .var_as("alice", g().add_n("User", vec![("name", "Alice")]))
      .var_as("bob", g().add_n("User", vec![("name", "Bob")]))
      .var_as(
          "linked",
          g()
              .n(NodeRef::var("alice"))
              .add_e(
                  "FOLLOWS",
                  NodeRef::var("bob"),
                  vec![("since", "2026-07-24")],
              )
              .count(),
      )
      .returning(["alice", "bob", "linked"]);
  ```

  ```ts TypeScript theme={"languages":{"custom":["languages/helixql.json"]}}
  writeBatch()
    .varAs("alice", g().addN("User", { name: "Alice" }))
    .varAs("bob", g().addN("User", { name: "Bob" }))
    .varAs(
      "linked",
      g()
        .n(NodeRef.var("alice"))
        .addE("FOLLOWS", NodeRef.var("bob"), { since: "2026-07-24" })
        .count(),
    )
    .returning(["alice", "bob", "linked"]);
  ```

  ```go Go theme={"languages":{"custom":["languages/helixql.json"]}}
  helix.WriteQuery("connect_users").
  	VarAs("alice", helix.G().AddN("User", helix.Props{helix.Prop("name", "Alice")})).
  	VarAs("bob", helix.G().AddN("User", helix.Props{helix.Prop("name", "Bob")})).
  	VarAs(
  		"linked",
  		helix.G().
  			N(helix.NodeVar("alice")).
  			AddE(
  				"FOLLOWS",
  				helix.NodeVar("bob"),
  				helix.Props{helix.Prop("since", "2026-07-24")},
  			).
  			Count(),
  	).
  	Returning("alice", "bob", "linked")
  ```

  ```python Python theme={"languages":{"custom":["languages/helixql.json"]}}
  (
      write_batch()
      .var_as("alice", g().add_n("User", {"name": "Alice"}))
      .var_as("bob", g().add_n("User", {"name": "Bob"}))
      .var_as(
          "linked",
          g()
          .n(NodeRef.var("alice"))
          .add_e("FOLLOWS", NodeRef.var("bob"), {"since": "2026-07-24"})
          .count(),
      )
      .returning(["alice", "bob", "linked"])
  )
  ```

  ```json JSON theme={"languages":{"custom":["languages/helixql.json"]}}
  {
    "request_type": "write",
    "query_name": "connect_users",
    "query": {
      "write": {
        "entries": [
          {
            "query": {
              "name": "alice",
              "root": {
                "add_n": {
                  "label": "User",
                  "properties": [
                    ["name", { "value": { "string": "Alice" } }]
                  ]
                }
              }
            }
          },
          {
            "query": {
              "name": "bob",
              "root": {
                "add_n": {
                  "label": "User",
                  "properties": [
                    ["name", { "value": { "string": "Bob" } }]
                  ]
                }
              }
            }
          },
          {
            "query": {
              "name": "linked",
              "root": {
                "count": {
                  "input": {
                    "add_e": {
                      "input": {
                        "nodes": {
                          "reference": { "var": "alice" }
                        }
                      },
                      "label": "FOLLOWS",
                      "to": { "var": "bob" },
                      "properties": [
                        ["since", { "value": { "string": "2026-07-24" } }]
                      ]
                    }
                  }
                }
              }
            }
          }
        ],
        "returns": ["alice", "bob", "linked"]
      }
    }
  }
  ```
</CodeGroup>

## Other mutations

| Intent                        | Operation                                     |
| ----------------------------- | --------------------------------------------- |
| Replace or add a property     | `setProperty` / `set_property`                |
| Remove a property             | `removeProperty` / `remove_property`          |
| Remove current nodes or edges | `drop`                                        |
| Remove a specific edge        | `dropEdge`, `dropEdgeLabeled`, `dropEdgeById` |
| Create an index               | `createIndexIfNotExists`                      |
| Drop an index                 | `dropIndex`                                   |

## Transaction behavior

All entries in the write batch commit or roll back together. Reads inside the batch can
refer to earlier mutations through named variables. Do not retry a write automatically
unless the full request is safe to replay.

## Next steps

<CardGroup cols={2}>
  <Card title="Typed parameters" icon="sliders" href="/database/helix-db/query-guides/parameters">
    Pass request-specific values without changing the AST shape.
  </Card>

  <Card title="Secondary indexes" icon="list" href="/database/helix-db/query-guides/secondary-indexes">
    Accelerate equality, uniqueness, and range lookups.
  </Card>
</CardGroup>