> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apostra.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Create signal
> Register a signal with key types, regions, and access records
`POST /api/v2/storefront/signals`
Registers a signal so it can be deployed and surfaced to buyers. You set the key types and regions at creation; `keyType` and `regions` are immutable afterward. Use `access` records to control visibility (`PUBLIC` or `PROPRIETARY`) and optional per-advertiser pricing.
## Request
```bash curl theme={null}
curl -X POST https://api.apostra.com/api/v2/storefront/signals \
-H "Authorization: Bearer $SCOPE3_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"signalId": "acme_high_value_customers",
"name": "Acme — High-Value Customers",
"description": "Top 10% LTV customers, refreshed weekly",
"keyType": ["rampid", "uid2"],
"regions": ["NORAM", "EMEA"],
"isLive": false
}'
```
```json With access and pricing theme={null}
{
"signalId": "acme_auto_intenders",
"name": "Acme — Auto Intenders",
"description": "In-market auto shoppers, last 30 days",
"keyType": ["maid"],
"regions": ["NORAM"],
"access": [
{
"advertiserId": 88421,
"visibility": "PROPRIETARY",
"price": {
"pricing_option_id": "po_cpm_standard",
"pricing_model": "cpm",
"currency": "USD",
"fixed_price": 2.5
}
}
],
"isLive": true
}
```
## Parameters
| Field | Type | Required | Notes |
| ------------- | --------- | -------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `signalId` | string | Yes | Caller-supplied stable identifier. Pattern `^[\w\-:.]+$`, max 255. **Immutable** |
| `name` | string | Yes | Human-readable name (max 255) |
| `keyType` | string\[] | Yes | Identifiers the segment is keyed on. At least one **context** type (`country`, `region`, `metro`, `topic`, `eidr`, `gracenote`, `isrc`, `gtin`, `rss_guid`, `isbn`, `url`, `url_hash`, `custom`) or **identity** type (`maid`, `rampid`, `rampid_derived`, `hashed_email`, `hashed_phone`, `id5`, `uid2`, `euid`, `pairid`) — never both classes on one signal. **Immutable** |
| `agentId` | string | No | Owning signals agent (for agent-managed signals) |
| `description` | string | No | What the segment represents (max 5000) |
| `regions` | string\[] | No | Availability regions: `NORAM`, `LATAM`, `EMEA`, `APAC`, `ANZ`, `GLOBAL` (max 6). **Immutable** |
| `metadata` | object | No | Free-form key/value metadata |
| `access` | object\[] | No | Access records. Each requires `advertiserId` (int64) and `visibility` (`PUBLIC` or `PROPRIETARY`); optional `price` |
| `isLive` | boolean | No | Whether the signal is deployed and accepting buys. Default `false` |
## Response
```json theme={null}
{
"signal": {
"id": 50213,
"signalId": "acme_high_value_customers",
"customerId": 1001,
"adcpAgentId": null,
"name": "Acme — High-Value Customers",
"description": "Top 10% LTV customers, refreshed weekly",
"keyType": ["rampid", "uid2"],
"regions": ["NORAM", "EMEA"],
"metadata": null,
"isLive": false,
"archivedAt": null,
"createdBy": "agent@acme.example",
"updatedBy": null,
"createdAt": "2026-06-06T12:00:00Z",
"updatedAt": "2026-06-06T12:00:00Z"
},
"access": []
}
```
The numeric `id` and the string `signalId` are both returned. Pass `signalId` to every sibling operation.
## Errors
* `400 VALIDATION_ERROR` — missing `signalId`, `name`, or `keyType`; malformed `signalId`; an empty `keyType` array; or a `keyType` array that mixes context types with identity types (a single signal must be one class or the other — see [Key types and the privacy boundary](/v2/object-guides/signal#key-types-and-the-privacy-boundary)).
* `401 UNAUTHORIZED` — missing or invalid bearer token.
See [Errors](/v2/reference/errors) for the full error contract.
## Related
All signal operations
Fields, lifecycle, and concepts
Change metadata and access records
Find external segments from agents