# Create a feed

Source: https://docs.settlemint.com/docs/user-guides/data-feeds/create-feed
Deploy an issuer-signed scalar feed or register a Chainlink-compatible feed for a global, asset, or identity subject.



Create a data feed in the DALP app when a workflow needs reusable market, asset, or identity data. A feed can be **global** for market-wide data, **asset-scoped** for one token, or **identity-scoped** for one identity.

DALP supports two creation paths:

* **Issuer-signed feed** - DALP deploys a scalar feed contract. Trusted issuers later publish signed EIP-712 updates to that feed.
* **Chainlink-compatible feed** - DALP registers an existing external feed address in the Feeds Directory. The external oracle operator still manages the source feed.

## Prerequisites [#prerequisites]

Before you start, make sure you have:

* The **Feeds manager** role assigned in platform access control
* A scalar feed **verification topic** already created, see [Create a topic](/docs/user-guides/data-feeds/create-topic)
* For issuer-signed feeds, a trusted issuer configured for the topic, see [Configure trusted issuers](/docs/user-guides/compliance/configure-trusted-issuers)
* For Chainlink-compatible feeds, the external oracle contract address you want DALP to register
* For asset-scoped feeds, the target asset already deployed

## Creation model [#creation-model]

<Mermaid
  chart="flowchart TD
    Scope[Choose feed scope] --> Subject{Does the scope need a subject?}
    Subject -->|Global| Zero[DALP uses the zero address]
    Subject -->|Asset-scoped| Asset[Select the deployed asset]
    Subject -->|Identity-scoped| Identity[Select the identity]
    Zero --> Topic[Select a scalar verification topic]
    Asset --> Topic
    Identity --> Topic
    Topic --> Source{Choose source type}
    Source -->|Issuer-signed| Deploy[DALP deploys and registers a scalar feed]
    Source -->|Chainlink-compatible| Register[DALP registers the external feed address]
    Deploy --> Verify[Open the feed detail page]
    Register --> Verify"
/>

The scope, subject, and topic identify the data slot. The source type decides whether DALP deploys the feed contract or records an existing Chainlink-compatible address for that same slot.

## Example configuration [#example-configuration]

Use a global issuer-signed feed for a reusable market price that trusted issuers will update inside DALP.

| Field            | Example value     | Why this value fits                                                                 |
| ---------------- | ----------------- | ----------------------------------------------------------------------------------- |
| Scope            | **Global**        | The price applies across the market rather than to one asset or identity            |
| Subject address  | Zero address      | DALP fills this automatically for global feeds                                      |
| Topic name       | `BTC/USD`         | The scalar topic identifies the value publishers submit                             |
| Source type      | **Issuer-signed** | DALP deploys the feed and validates signed updates from trusted issuers             |
| Decimals         | `8`               | Common precision for USD price feeds                                                |
| Description      | `BTC/USD`         | Human-readable label stored with the deployed feed                                  |
| History mode     | `Bounded`         | Keeps a fixed update history instead of only the latest value or all values forever |
| History size     | `100`             | Stores the latest 100 submitted values                                              |
| Require positive | Enabled           | Rejects zero or negative price submissions                                          |
| Drift allowance  | `300` seconds     | Rejects updates whose observed time is more than five minutes from block time       |

After registration, a trusted issuer can publish the first `BTC/USD` value for the same topic. If you already operate a Chainlink-compatible oracle for the price, choose **Chainlink** instead and enter that feed address; DALP registers the address but does not operate the external oracle.

## Steps [#steps]

<Steps>
  <Step>
    ### Navigate to data feeds [#navigate-to-data-feeds]

    Go to **Platform Settings** > **Data Feeds** in the sidebar. The page lists registered feeds and their latest indexed values.

    ![Data Feeds page](/docs/data-feeds/data-feeds-empty.webp)
  </Step>

  <Step>
    ### Open the create feed form [#open-the-create-feed-form]

    Click **Create feed** to open the feed creation form.

    ![Create feed form](/docs/data-feeds/create-feed-form.webp)
  </Step>

  <Step>
    ### Select the feed scope [#select-the-feed-scope]

    Choose the scope first. The scope determines the feed subject address.

    | Scope               | Use it for                                                                                   | Subject address                               |
    | ------------------- | -------------------------------------------------------------------------------------------- | --------------------------------------------- |
    | **Global**          | Market-wide data such as BTC/USD, ETH/USD, or FX rates                                       | DALP uses the zero address automatically      |
    | **Asset-scoped**    | Data tied to one deployed token, such as NAV, interest rate, collateral ratio, or risk score | Select the asset from the subject dropdown    |
    | **Identity-scoped** | Data tied to one identity                                                                    | Select the identity from the subject dropdown |

    For asset or identity scope, the form shows a **Subject address** selector. Pick the exact asset or identity before continuing.
  </Step>

  <Step>
    ### Select the topic and source type [#select-the-topic-and-source-type]

    Fill in the common feed fields:

    * **Data format** - Scalar is the supported feed format.
    * **Topic name** - Select a scalar feed topic from the dropdown. The form shows the derived topic ID so you can confirm the topic being registered.
    * **Source type** - Choose **Issuer-signed** to deploy a DALP-managed feed, or **Chainlink** to register an existing external feed address.

    <Callout type="info" title="Issuer-signed availability">
      If the issuer-signed feed factory is not installed for the current system, the app only offers the
      Chainlink-compatible registration path. Finish the platform feed setup before creating issuer-signed feeds.
    </Callout>
  </Step>

  <Step>
    ### Configure the selected source [#configure-the-selected-source]

    For an **issuer-signed feed**, configure the contract DALP will deploy:

    | Field                | What to enter                                                                                                                               |
    | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
    | **Decimals**         | Feed value precision from `0` to `18`. USD price feeds often use `8`; integer metrics can use `0`.                                          |
    | **Description**      | A plain-language label for what the feed measures, such as `USDT / USD` or `BTC/USD spot price`.                                            |
    | **History mode**     | `Latest only` keeps the most recent value, `Bounded` keeps a fixed number of values, and `Full` keeps all values.                           |
    | **History size**     | Required only for `Bounded` history. Use at least `1`.                                                                                      |
    | **Require positive** | Rejects submitted values that are zero or negative.                                                                                         |
    | **Drift allowance**  | Maximum allowed difference, in seconds, between the submitted `observedAt` time and the block timestamp. Use `0` to disable drift checking. |

    The form defaults issuer-signed feeds to `18` decimals, `Latest only` history, no positivity check, and `0` seconds of drift allowance. Change those values before creating the feed if your issuer updates need a different retention, precision, or validation model.

    For a **Chainlink-compatible feed**, enter the external **Feed address**. DALP registers that address for the selected subject and topic with scalar feed kind. DALP does not deploy or operate that external oracle.

    ![Filled create feed form](/docs/data-feeds/create-feed-filled.webp)
  </Step>

  <Step>
    ### Review and confirm [#review-and-confirm]

    Click **Continue** to review the configuration summary. Check the scope, subject, topic, source type, and source-specific fields before submitting.

    Click **Register feed** and enter your PIN to authenticate the transaction.

    ![Feed creation confirmation](/docs/data-feeds/create-feed-confirm.webp)
  </Step>

  <Step>
    ### Verify the feed [#verify-the-feed]

    After the transaction confirms, the feed appears in the Data Feeds list. Open the feed row to review the registered subject, topic, source type, configuration, and latest value.

    ![Data Feeds list with created feed](/docs/data-feeds/data-feeds-created.webp)

    ![Feed detail page](/docs/data-feeds/feed-detail.webp)
  </Step>
</Steps>

## What happens after registration [#what-happens-after-registration]

| Source type          | What DALP does                                                                                | What you do next                                                          |
| -------------------- | --------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------- |
| Issuer-signed        | Deploys and registers a scalar feed contract                                                  | Publish the first value through a trusted issuer                          |
| Chainlink-compatible | Registers the external feed address in the Feeds Directory for the selected subject and topic | Confirm the external oracle keeps updating and that DALP indexes the feed |

Issuer-signed properties are set when the feed is deployed. If you need different decimals, history mode, positivity checks, or drift controls, create a new feed with the desired configuration.

## Field summary [#field-summary]

| Field            | Required                       | Applies to                 | Notes                                                                         |
| ---------------- | ------------------------------ | -------------------------- | ----------------------------------------------------------------------------- |
| Scope            | Yes                            | All feeds                  | Determines the subject address                                                |
| Subject address  | Asset and identity scopes only | All feeds                  | Auto-filled for global scope                                                  |
| Data format      | Yes                            | All feeds                  | Scalar feed values are supported                                              |
| Topic name       | Yes                            | All feeds                  | Must be a scalar feed topic                                                   |
| Source type      | Yes                            | All feeds                  | Choose between issuer-signed deployment and Chainlink-compatible registration |
| Feed address     | Yes                            | Chainlink-compatible feeds | Existing external oracle contract address                                     |
| Decimals         | Yes                            | Issuer-signed feeds        | Range: `0` to `18`                                                            |
| Description      | Yes                            | Issuer-signed feeds        | Human-readable description stored with the feed                               |
| History mode     | Yes                            | Issuer-signed feeds        | Controls value retention                                                      |
| History size     | Bounded mode only              | Issuer-signed feeds        | Minimum: `1`                                                                  |
| Require positive | No                             | Issuer-signed feeds        | Rejects non-positive values when enabled                                      |
| Drift allowance  | No                             | Issuer-signed feeds        | Time window in seconds; `0` disables drift checking                           |

## Troubleshooting [#troubleshooting]

| Issue                              | What to check                                                                                                                                                                                                                                   |
| ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Create feed button not visible     | Confirm your wallet has the **Feeds manager** role in platform access control.                                                                                                                                                                  |
| Issuer-signed option not available | Confirm the issuer-signed feed factory is installed for the system.                                                                                                                                                                             |
| No topics in the dropdown          | Create a scalar feed topic first, see [Create a topic](/docs/user-guides/data-feeds/create-topic).                                                                                                                                              |
| Continue button disabled           | Select a topic first. For asset or identity scope, also choose a subject address. For issuer-signed feeds, fill in the description and bounded history size when applicable. For Chainlink-compatible feeds, fill in the external feed address. |
| Asset not in subject dropdown      | Confirm the asset is deployed and visible under **Asset management**.                                                                                                                                                                           |
| Transaction fails                  | Check your wallet gas balance, PIN or OTP setup, subject address, and feed factory availability.                                                                                                                                                |

## Next steps [#next-steps]

* For issuer-signed feeds, [publish a feed update](/docs/user-guides/data-feeds/publish-feed-update) to submit the first value.
* For Chainlink-compatible feeds, open the feed detail page after indexing and confirm the external oracle value is visible.
* To understand how feeds fit the wider data model, read the [Data feeds overview](/docs/user-guides/data-feeds/overview).