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

# write

> Contract, placement, related fields and source examples for this Nika YAML field.

[Language reference](/reference/language/overview) / `write`

## Meaning and placement

### → permits → fs

The schema declares this field at the location below.

| Property        | Declaration                                          |
| --------------- | ---------------------------------------------------- |
| Requirement     | Optional in this object                              |
| Schema location | `/properties/permits/properties/fs/properties/write` |
| type            | "array"                                              |

**In the same object:** [read](/reference/language/words/read)

[Schema source (use the pointer above)](https://github.com/supernovae-st/nika-spec/blob/c5ebbb7b862b68bc6cf7235efba61173b844afc6/schemas/workflow.schema.json)

## In a source template

Excerpt from `templates/chain.nika.yaml`, source lines 40–49. This is a fragment, not a runnable workflow.

```yaml illustration theme={"system"}
  # them in step with the two `const:` entries above.
  fs:
    read: ["./README.md"]     # SLOT: same path as const.source
    write: ["./output.md"]    # SLOT: same path as const.destination

tasks:
  gather:
    invoke:                         # SLOT: the fact source · nika:read / nika:fetch / exec
      tool: "nika:read"
      args: { path: "${{ const.source }}" }
```

### Templates containing this field

| Template                               | Source                                                                                                                                       |
| -------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- |
| `templates/chain.nika.yaml`            | [Line 43](https://github.com/supernovae-st/nika-spec/blob/c5ebbb7b862b68bc6cf7235efba61173b844afc6/templates/chain.nika.yaml#L43)            |
| `templates/docker-report.nika.yaml`    | [Line 44](https://github.com/supernovae-st/nika-spec/blob/c5ebbb7b862b68bc6cf7235efba61173b844afc6/templates/docker-report.nika.yaml#L44)    |
| `templates/etl-state.nika.yaml`        | [Line 59](https://github.com/supernovae-st/nika-spec/blob/c5ebbb7b862b68bc6cf7235efba61173b844afc6/templates/etl-state.nika.yaml#L59)        |
| `templates/media-asset-pack.nika.yaml` | [Line 42](https://github.com/supernovae-st/nika-spec/blob/c5ebbb7b862b68bc6cf7235efba61173b844afc6/templates/media-asset-pack.nika.yaml#L42) |

These are literal key occurrences in the source files, not an execution or conformance claim. [How to instantiate a template](/guides/templates).

## Contract and implementation

This page projects the named specification revision. Check [released engine status](/reference/status) and [the validation workflow](/guides/agent-authoring) before running a file. An optional field is not evidence that every engine supports every value.

Canonical identity: `language:word:write`. Spec revision: [`c5ebbb7b862b`](https://github.com/supernovae-st/nika-spec/tree/c5ebbb7b862b68bc6cf7235efba61173b844afc6).

[How documentation stays connected](/reference/knowledge-system).