---
# @generated by sylphx-gen 0.1.0 from contracts@e145cc7cf1bc9605f2b27439e5e17ed76a1a2fd7e7021906a013f7565e4a0cd5. Do not edit.
title: "Create a config flag"
description: "`config.config_flags.create` (POST /v1/{parent}/config_flags): Creates a config flag; the Operation is done when every cell serves it."
type: reference
product: flags
summary: "Creates a config flag; the Operation is done when every cell serves it."
updated: 2026-09-28
nav: false
---

Creates a config flag; the Operation is done when every cell serves it.

- **Path** `POST https://api.sylphx.com/v1/orgs/acme/projects/shop/envs/production/config_flags`
- **Scope** `config:write`
- **Effect** `write` — a successful call changes state.
- **Collection** [config_flags](/docs/api/config_flags)
- **Query** `config_flag_id`, `validate_only`
- **Operation** answers with an `Operation`; the result is `ConfigFlag`

## Request

| Field | Type | What it is |
| --- | --- | --- |
| `parent` | `string` | The environment to create in. Required. |
| `config_flag` | `ConfigFlag` | The config flag to create; only spec and caller-writable metadata are read. Required. |
| `config_flag_id` | `string` | The id of the new config flag, the key evaluators ask for; the server assigns one when empty. |
| `validate_only` | `bool` | Validate and return the result without writing anything. |

### ConfigFlag

| Field | Type | What it is |
| --- | --- | --- |
| `name` | `string` | `orgs/{org}/projects/{project}/envs/{env}/config_flags/{config_flag}`; the id is the key evaluators ask for. |
| `meta` | `ResourceMeta` | Resource metadata. |
| `spec` | `ConfigFlagSpec` | Desired state. Required. |

### ResourceMeta

| Field | Type | What it is |
| --- | --- | --- |
| `labels` | `map<string, string>` | Caller-writable, indexed labels (AIP-122 label rules). |
| `annotations` | `map<string, string>` | Caller-writable, unindexed annotations. |
| `display_name` | `string` | Caller-writable human-readable name. |

### ConfigFlagSpec

| Field | Type | What it is |
| --- | --- | --- |
| `value_type` | `ConfigValueType` | The type every value of the flag has. Required. One of `bool`, `string`, `int64`, `double`, `json`. |
| `default_value` | `value` | The value when no rule matches, or when the flag is disabled. Required. |
| `enabled` | `bool` | When false, every evaluation returns `default_value` and the rules are skipped: a kill switch. Default true. |
| `rules` | `TargetingRule[]` | Targeting rules, first match wins. |
| `description` | `string` | What the flag is for. |
| `client_visible` | `bool` | Publishable keys (browsers, mobile apps) may evaluate it with `config_flags:evaluate`; default false, so a server-only flag's value never reaches a device. Secret keys evaluate every flag. |

### TargetingRule

| Field | Type | What it is |
| --- | --- | --- |
| `value` | `value` | The value served when the rule matches; of the flag's type. Required. |
| `percentage` | `int32` | Serve `value` to evaluations whose bucket is below this, from 0 to 100; default 100. The rest fall through to the next rule. |
| `bucket_attribute` | `string` | The context attribute hashed for the bucket: `user_id`, `anonymous_id`, or an attribute path; default `user_id`, else `anonymous_id`. An evaluation without it never matches a rule below 100 percent. |
| `description` | `string` | What the rule is for. |
| `conditions` | `TargetingCondition[]` | Conditions over the evaluation context; all must hold. None matches every evaluation. |

## Response

| Field | Type | What it is |
| --- | --- | --- |
| `name` | `string` | `{parent-of-target}/operations/{operation}`. |
| `target` | `string` | The name of the Resource being changed. |
| `target_generation` | `int64` | The generation this Operation waits for. |
| `verb` | `OperationVerb` | What the Operation does. One of `create`, `update`, `delete`, `custom`. |
| `custom_verb` | `string` | The custom method verb when `verb` is CUSTOM, for example `revoke`. |
| `done` | `bool` | Whether the Operation has finished. |
| `create_time` | `timestamp` | When the Operation started. |
| `end_time` | `timestamp` | When the Operation finished. |
| `response` | `any` | The settled Resource (or Empty for a delete). One of the `result` group. |
| `error` | `ProblemDetails` | The failure, as the one error body. One of the `result` group. |
| `progress` | `OperationProgress` | Progress while not `done`. |

### ProblemDetails

| Field | Type | What it is |
| --- | --- | --- |
| `type` | `string` | `https://sylphx.com/docs/errors/<code in kebab-case>`. |
| `title` | `string` | A short customer-safe summary of the problem class. |
| `status` | `int32` | The HTTP status, fixed by `grpc_status`. |
| `detail` | `string` | A customer-safe explanation of this occurrence. Never contains SQL, stack traces, internal hostnames, or another tenant's data. |
| `instance` | `string` | The request id (`Sylphx-Request-Id`). |
| `code` | `string` | The stable UPPER_SNAKE code, one of ErrorCode without its prefix. |
| `grpc_status` | `string` | One of the 16 canonical gRPC status names, for example `ABORTED`. |
| `retryable` | `bool` | Whether the same request may be retried. |
| `effect` | `ErrorEffect` | What the failed call committed. One of `none`, `applied`, `unknown`. |
| `retry_after_ms` | `int64` | How long to wait before retrying, when the server knows. |
| `details` | `any[]` | Typed details such as PreconditionFailure or EntitlementDenial. |

### OperationProgress

| Field | Type | What it is |
| --- | --- | --- |
| `percent` | `int32` | Percent complete, when the controller can tell. |
| `message` | `string` | A customer-safe progress message. |
| `conditions` | `Condition[]` | The target's conditions when this progress was read. |

### Condition

| Field | Type | What it is |
| --- | --- | --- |
| `type` | `string` | The condition type, for example `Ready`. |
| `status` | `ConditionStatus` | Whether the condition holds. One of `true`, `false`, `unknown`. |
| `observed_generation` | `int64` | The generation this observation was made against. |
| `reason` | `string` | A machine-readable UpperCamelCase reason. |
| `message` | `string` | A customer-safe human-readable message. |
| `severity` | `Severity` | How severe a FALSE condition is. One of `info`, `warning`, `error`. |
| `transition_time` | `timestamp` | When `status` last changed. |

## Errors

- [`UNAUTHENTICATED`](/docs/api/errors/UNAUTHENTICATED) — No valid key or token was presented.
- [`PERMISSION_DENIED`](/docs/api/errors/PERMISSION_DENIED) — The key lacks the method's permission.
- [`UNKNOWN_FIELD`](/docs/api/errors/UNKNOWN_FIELD) — The request has a field the schema does not know.
- [`INVALID_FIELD`](/docs/api/errors/INVALID_FIELD) — A field failed validation.
- [`RESOURCE_ALREADY_EXISTS`](/docs/api/errors/RESOURCE_ALREADY_EXISTS) — A Resource with this name exists.
- [`IDEMPOTENCY_KEY_REUSED`](/docs/api/errors/IDEMPOTENCY_KEY_REUSED) — An Idempotency-Key was reused with another body.
- [`IDEMPOTENCY_IN_PROGRESS`](/docs/api/errors/IDEMPOTENCY_IN_PROGRESS) — The first call with this Idempotency-Key is still running.
- [`PLAN_LIMIT_REACHED`](/docs/api/errors/PLAN_LIMIT_REACHED) — The plan's limit is reached.

Every error arrives in the body [Errors](/docs/platform/errors) describes.

## Examples

**cURL**

```curl
curl -X POST "https://api.sylphx.com/v1/orgs/acme/projects/shop/envs/production/config_flags" \
  -H "Authorization: Bearer $SYLPHX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"spec":{"default_value":{},"value_type":"bool"}}'
```

**TypeScript**

```ts
const operation = await sylphx.config.configFlags.create({ configFlag: { spec: { defaultValue: {}, valueType: 'bool' } }, parent: 'orgs/acme/projects/shop/envs/production' })
```

**Rust**

```rust
let mut req = sylphx::config::CreateConfigFlagRequest::default();
req.config_flag = Some(sylphx::config::ConfigFlag {
    spec: Some(sylphx::config::ConfigFlagSpec {
        default_value: Some(Default::default()),
        value_type: sylphx::config::ConfigValueType::Bool,
        ..Default::default()
    }),
    ..Default::default()
});
req.parent = "orgs/acme/projects/shop/envs/production".to_string();
let operation = sx.config().config_flags().create(req).await?;
```

**CLI**

```bash
sylphx config config-flags create --parent orgs/acme/projects/shop/envs/production --spec.value-type bool
```

**Terraform**

```hcl
resource "sylphx_config_config_flag" "config_flag" {
  config_flag_id = "config_flag"
  parent         = "orgs/acme/projects/shop/envs/production"
  spec           = { default_value = {}, value_type = "bool" }
}
```

**MCP**

```json
{ "method_id": "config.config_flags.create", "args": {"config_flag":{"spec":{"default_value":{},"value_type":"bool"}},"parent":"orgs/acme/projects/shop/envs/production"} }
```