open-consul/website/content/commands/config/write.mdx

---
layout: commands
page_title: 'Commands: Config Write'
---

# Consul Config Write

Command: `consul config write`

Corresponding HTTP API Endpoint: [\[PUT\] /v1/config](/consul/api-docs/config#apply-configuration)

The `config write` command creates or updates a centralized config entry.
See the [configuration entries docs](/consul/docs/agent/config-entries) for more
details about configuration entries.

The table below shows this command's [required ACLs](/consul/api-docs/api-structure#authentication). Configuration of
[blocking queries](/consul/api-docs/features/blocking) and [agent caching](/consul/api-docs/features/caching)
are not supported from commands, but may be from the corresponding HTTP endpoint.

| ACL Required<sup>1</sup>                                      |
| ------------------------------------------------------------- |
| `service:write`<br />`operator:write`<br />`intentions:write` |

<p>
  <sup>1</sup> The actual ACL required depends on the config entry kind being
  updated:
</p>

| Config Entry Kind   | Required ACL       |
| ------------------- | ------------------ |
| ingress-gateway     | `operator:write`   |
| proxy-defaults      | `operator:write`   |
| service-defaults    | `service:write`    |
| service-intentions  | `intentions:write` |
| service-resolver    | `service:write`    |
| service-router      | `service:write`    |
| service-splitter    | `service:write`    |
| terminating-gateway | `operator:write`   |

## Usage

Usage: `consul config write [options] FILE`

#### Command Options

- `-cas` - Specifies to use a Check-And-Set operation. If the index is
  0, Consul will only store the entry if it does not already exist. If the index is
  non-zero, the entry is only set if the current index matches the `ModifyIndex`
  of that entry.

#### Enterprise Options

@include 'http_api_partition_options.mdx'

@include 'http_api_namespace_options.mdx'

#### API Options

@include 'http_api_options_client.mdx'

## Examples

From file:

    $ consul config write web-defaults.json

From stdin:

    $ consul config write -

### Config Entry examples

All config entries must have a `Kind` when registered. See
[Service Mesh - Config Entries](/consul/docs/connect/config-entries) for the list of
supported config entries.

#### Service defaults

Service defaults control default global values for a service, such as the
protocol and Connect fields.

```json
{
  "Kind": "service-defaults",
  "Name": "web",
  "Protocol": "http"
}
```

- `Name` - Sets the name of the config entry. For service defaults, this must be
  the name of the service being configured.

- `Protocol` - Sets the protocol of the service. This is used by Connect proxies
  for things like observability features.

- `Connect` - This block contains Connect-related fields for the service.

  - `SidecarProxy` - Sets whether or not instances of this service should get a
    sidecar proxy by default.

#### Proxy defaults

Proxy defaults allow for configuring global config defaults across all services
for Connect proxy config. Currently, only one global entry is supported.

```json
{
  "Kind": "proxy-defaults",
  "Name": "global",
  "Config": {
    "foo": 1
  }
}
```

- `Name` - Sets the name of the config entry. Currently, only a single `proxy-defaults`
  entry with the name `global` is supported.

* `Config` - An arbitrary map of configuration values used by Connect proxies.