DALP price-feed registry read API for valuation

Read the on-chain price-feed registry through DALP. List registered feeds, read one feed, resolve a feed for a subject and topic, and inspect latest value, historical rounds, and staleness.

A bank that values tokenized assets needs to know which price feed backs each asset, what the feed last reported, and whether that value is fresh enough to act on. The price-feed registry answers those questions. It tracks every feed registered for the system, the subject and topic each feed prices, and the latest signed value the feed produced.

The read endpoints under /api/v2/system/feeds return DALP response envelopes and use the shared collection query format for lists. Feed registration, replacement, and value submission are governance operations outside the scope of this reference.

For fiat currency pair rates such as EUR / USD, use the exchange rates API, which resolves one rate per pair on top of these feeds.

Endpoints

Job	Method and path	Use it for	Response shape
List feeds	`GET /api/v2/system/feeds`	Discover registered feeds with their subject, topic, decimals, scope, and latest value.	Collection envelope with `data`, `meta`, and `links`.
Read one feed	`GET /api/v2/system/feeds/{feedAddress}`	Read full details for one feed by its contract address.	Single-resource envelope with `data` and `links.self`.
Read feed configuration	`GET /api/v2/system/feeds/{feedAddress}/config`	Read the immutable settings an issuer-signed feed enforces on every update.	Single-resource envelope with `data` and `links.self`.
Resolve a feed	`GET /api/v2/system/feeds/resolve`	Find the feed registered for a subject and topic pair.	Single-resource envelope with `data` and `links.self`.
Read feed capabilities	`GET /api/v2/system/feeds/capabilities`	Check whether the feed directory, factories, and adapters are installed.	Single-resource envelope with `data` and `links.self`.
Read the latest value	`GET /api/v2/system/feeds/{feedAddress}/latest`	Read the most recent round directly from a feed contract.	Single-resource envelope with `data` and `links.self`.
Read a historical round	`GET /api/v2/system/feeds/{feedAddress}/round/{roundId}`	Read one earlier round by its round identifier.	Single-resource envelope with `data` and `links.self`.
Evaluate staleness	`GET /api/v2/system/feeds/{feedAddress}/staleness`	Decide whether a feed value is too old to use against an age threshold.	Single-resource envelope with `data` and `links.self`.
List issuer-signed feeds	`GET /api/v2/system/feeds/issuer-signed`	List feeds the platform created and signs values for in this system.	Collection envelope with `data`, `meta`, and `links`.
List adapter-backed feeds	`GET /api/v2/system/feeds/adapters`	List feeds that publish through a stable adapter address.	Collection envelope with `data`, `meta`, and `links`.

A feed prices a subject for a topic. The subject is the address the feed describes, such as a token. The topic identifies what the value means, such as a price in a given currency. A description follows the <BASE> / <QUOTE> convention, so a token price feed reads as USDT / USD and a global currency feed reads as EUR / USD.

List registered feeds

The list endpoint returns the feeds registered in the system, most recently registered first. Each record carries the feed's identity, its latest indexed value, and whether it is active.

curl --globoff "https://your-platform.example.com/api/v2/system/feeds?filter[isActive]=true&filter[scope]=asset&page[limit]=50&sort=-registeredAt" \
  -H "X-Api-Key: sm_dalp_xxxxxxxxxxxxxxxx"

The response uses the collection envelope:

{
  "data": [
    {
      "id": "0x1111111111111111111111111111111111111111",
      "feedAddress": "0x1111111111111111111111111111111111111111",
      "subject": "0x2222222222222222222222222222222222222222",
      "topicId": "1",
      "kind": "SCALAR",
      "schemaHash": "0x3333333333333333333333333333333333333333333333333333333333333333",
      "decimals": 8,
      "scope": "asset",
      "factory": { "id": "0x4444444444444444444444444444444444444444", "typeId": "issuer-signed-scalar-feed" },
      "creator": { "id": "0x5555555555555555555555555555555555555555" },
      "adapterAddress": null,
      "isActive": true,
      "registeredAt": "2026-03-22T10:30:00.000Z",
      "latestValue": {
        "roundId": 12,
        "answer": "100000000",
        "observedAt": "2026-03-22T10:30:00.000Z",
        "updatedAt": "2026-03-22T10:30:00.000Z",
        "issuer": "0x6666666666666666666666666666666666666666",
        "signer": "0x7777777777777777777777777777777777777777"
      },
      "description": "USDT / USD"
    }
  ],
  "meta": {
    "total": 1,
    "facets": {
      "kind": [{ "value": "SCALAR", "count": 1 }],
      "scope": [{ "value": "asset", "count": 1 }],
      "isActive": [{ "value": "true", "count": 1 }]
    }
  },
  "links": {
    "self": "/v2/system/feeds?filter[isActive]=true&filter[scope]=asset&page[limit]=50&page[offset]=0&sort=-registeredAt",
    "first": "/v2/system/feeds?filter[isActive]=true&filter[scope]=asset&page[limit]=50&page[offset]=0&sort=-registeredAt",
    "next": null,
    "prev": null,
    "last": "/v2/system/feeds?filter[isActive]=true&filter[scope]=asset&page[limit]=50&page[offset]=0&sort=-registeredAt"
  }
}

latestValue is null until the feed produces its first round. Read it to learn the feed's most recent answer without a second call. The answer is an integer string in feed units: divide it by 10 to the power of decimals to get the human value, and use decimal arithmetic rather than binary floating-point in financial workflows.

The kind, scope, and isActive fields are facetable. The meta.facets block counts the matching feeds per value, which lets a picker show how many feeds sit behind each option without a separate count query.

Read one feed

Call the single-feed read when you already hold the feed contract address. It returns the same record shape as a list row.

curl "https://your-platform.example.com/api/v2/system/feeds/0x1111111111111111111111111111111111111111" \
  -H "X-Api-Key: sm_dalp_xxxxxxxxxxxxxxxx"

{
  "data": {
    "id": "0x1111111111111111111111111111111111111111",
    "feedAddress": "0x1111111111111111111111111111111111111111",
    "subject": "0x2222222222222222222222222222222222222222",
    "topicId": "1",
    "kind": "SCALAR",
    "decimals": 8,
    "scope": "asset",
    "isActive": true,
    "registeredAt": "2026-03-22T10:30:00.000Z",
    "latestValue": {
      "roundId": 12,
      "answer": "100000000",
      "observedAt": "2026-03-22T10:30:00.000Z",
      "issuer": "0x6666666666666666666666666666666666666666",
      "signer": "0x7777777777777777777777777777777777777777"
    },
    "description": "USDT / USD"
  },
  "links": {
    "self": "/v2/system/feeds/0x1111111111111111111111111111111111111111"
  }
}

Read immutable feed configuration

An issuer-signed feed fixes its trust and validation rules at creation, and the contract enforces them on every signed update. Read its configuration before you accept a feed's value into a valuation or settlement workflow. The response confirms what the feed actually guarantees:

which subject and topic it prices,
the schema hash its values must match,
whether it rejects non-positive answers,
how far ahead of block time a value's timestamp may sit,
and which trusted-issuer and topic-scheme registries it checks signatures against.

These settings cannot change after deployment, so this read is the source for an auditor or risk reviewer verifying a feed's controls.

curl "https://your-platform.example.com/api/v2/system/feeds/0x1111111111111111111111111111111111111111/config" \
  -H "X-Api-Key: sm_dalp_xxxxxxxxxxxxxxxx"

{
  "data": {
    "feedAddress": "0x1111111111111111111111111111111111111111",
    "subject": "0x2222222222222222222222222222222222222222",
    "topicId": "1",
    "expectedSchemaHash": "0x3333333333333333333333333333333333333333333333333333333333333333",
    "decimals": 8,
    "description": "USDT / USD",
    "historyMode": "FULL",
    "historySize": 0,
    "requirePositive": true,
    "driftAllowance": 0,
    "domainSeparator": "0x8888888888888888888888888888888888888888888888888888888888888888",
    "trustedIssuersRegistry": "0x9999999999999999999999999999999999999999",
    "topicSchemeRegistry": "0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
  },
  "links": { "self": "/v2/system/feeds/0x1111111111111111111111111111111111111111/config" }
}

requirePositive set to true means the feed rejects zero and negative answers. driftAllowance is the maximum number of seconds an update's observedAt timestamp may sit ahead of the chain's block time, which tolerates small signer clock skew; 0 requires the timestamp to be at or before block time. historyMode and historySize describe how many past rounds the feed retains: LATEST_ONLY keeps only the current round, BOUNDED keeps up to historySize rounds, and FULL keeps the complete history. The feed validates each update signature against trustedIssuersRegistry. At feed creation the factory derives the schema hash from topicSchemeRegistry and pins it as expectedSchemaHash; per-update enforcement compares the update schema hash to that pinned value, not to the live registry. Those addresses tell you which authorities the feed trusts. This endpoint serves issuer-signed scalar feeds; a feed address that does not resolve to one returns a not-found error.

Resolve a feed for a subject and topic

When you know what you want to price but not which feed serves it, resolve the feed by its subject and topic. Pass subject with either topicName or topicId (or both).

curl --globoff "https://your-platform.example.com/api/v2/system/feeds/resolve?subject=0x2222222222222222222222222222222222222222&topicId=1" \
  -H "X-Api-Key: sm_dalp_xxxxxxxxxxxxxxxx"

{
  "data": {
    "exists": true,
    "feedAddress": "0x1111111111111111111111111111111111111111",
    "kind": "SCALAR",
    "schemaHash": "0x3333333333333333333333333333333333333333333333333333333333333333",
    "adapterAddress": null,
    "indexed": {
      "decimals": 8,
      "registeredAt": "2026-03-22T10:30:00.000Z",
      "latestValue": {
        "roundId": 12,
        "answer": "100000000",
        "observedAt": "2026-03-22T10:30:00.000Z",
        "issuer": "0x6666666666666666666666666666666666666666",
        "signer": "0x7777777777777777777777777777777777777777"
      }
    }
  },
  "links": {
    "self": "/v2/system/feeds/resolve?subject=0x2222222222222222222222222222222222222222&topicId=1"
  }
}

When no feed is registered for the pair, exists is false and feedAddress, kind, schemaHash, adapterAddress, and indexed are null. The indexed block is also null for a registered feed the index has not yet enriched. Read exists before you trust the rest of the record.

Read the latest value and historical rounds

The latest and round endpoints read directly from the feed contract, so they return on-chain data exactly as the contract reports it. The latest endpoint returns the most recent round with a formattedAnswer already converted into human units.

curl "https://your-platform.example.com/api/v2/system/feeds/0x1111111111111111111111111111111111111111/latest" \
  -H "X-Api-Key: sm_dalp_xxxxxxxxxxxxxxxx"

{
  "data": {
    "feedAddress": "0x1111111111111111111111111111111111111111",
    "roundId": "12",
    "answer": "100000000",
    "decimals": 8,
    "formattedAnswer": "1.00000000",
    "startedAt": "2026-03-22T10:29:50.000Z",
    "updatedAt": "2026-03-22T10:30:00.000Z",
    "answeredInRound": "12",
    "description": "USDT / USD",
    "version": "1"
  },
  "links": { "self": "/v2/system/feeds/0x1111111111111111111111111111111111111111/latest" }
}

Pass a round identifier to read one earlier round. The roundId path parameter is a non-negative integer string.

curl "https://your-platform.example.com/api/v2/system/feeds/0x1111111111111111111111111111111111111111/round/11" \
  -H "X-Api-Key: sm_dalp_xxxxxxxxxxxxxxxx"

{
  "data": {
    "roundId": "11",
    "answer": "99950000",
    "startedAt": "2026-03-22T09:29:50.000Z",
    "updatedAt": "2026-03-22T09:30:00.000Z",
    "answeredInRound": "11"
  },
  "links": { "self": "/v2/system/feeds/0x1111111111111111111111111111111111111111/round/11" }
}

Evaluate staleness

A valuation workflow should reject a price that is too old. Pass maxAgeSeconds, the longest age you will accept, and the endpoint compares the latest round timestamp against the current platform time.

curl --globoff "https://your-platform.example.com/api/v2/system/feeds/0x1111111111111111111111111111111111111111/staleness?maxAgeSeconds=3600" \
  -H "X-Api-Key: sm_dalp_xxxxxxxxxxxxxxxx"

{
  "data": {
    "feedAddress": "0x1111111111111111111111111111111111111111",
    "latestUpdatedAt": "2026-03-22T10:30:00.000Z",
    "currentTimestamp": "2026-03-22T10:45:00.000Z",
    "ageSeconds": 900,
    "maxAgeSeconds": 3600,
    "isStale": false,
    "roundId": "12",
    "answer": "100000000"
  },
  "links": { "self": "/v2/system/feeds/0x1111111111111111111111111111111111111111/staleness?maxAgeSeconds=3600" }
}

isStale is true when ageSeconds is greater than maxAgeSeconds. Read isStale as the decision and ageSeconds as the supporting evidence.

List by creation path

Two narrower list endpoints split feeds by how they publish values. Both use the same collection envelope as the main list endpoint.

GET /api/v2/system/feeds/issuer-signed returns feeds the platform created through its factory and signs values for. Each record carries feedAddress, subject, topicId, and creator.
GET /api/v2/system/feeds/adapters returns feeds that publish through a stable adapter address, which keeps a fixed consumer address while the underlying source changes. Each record carries adapterAddress, subject, and topicId.

Use the main list endpoint when you want the full feed record with the latest value; use these two when you only need to enumerate feeds by their publishing mechanism.

Read feed capabilities

The capabilities endpoint reports whether the feed directory, factories, and adapter factory are installed for the system. Read it before you assume the feed endpoints will return data, since an organization can run without the feed modules installed.

curl "https://your-platform.example.com/api/v2/system/feeds/capabilities" \
  -H "X-Api-Key: sm_dalp_xxxxxxxxxxxxxxxx"

Parameters and fields

Field	Location	Type	Notes
`feedAddress`	Path or filter	EVM address	Feed contract address. The list endpoint supports `filter[feedAddress]`.
`roundId`	Path	integer string	Round identifier on the historical round read.
`maxAgeSeconds`	Query	positive integer	Longest acceptable value age on the staleness read.
`subject`	Query or field	EVM address	Address the feed prices, such as a token. Required on resolve and supported as a list filter.
`topicId`	Query or field	numeric string	Topic identifier for the priced value. Supply `topicId` or `topicName` on resolve.
`topicName`	Query	string	Topic name alternative to `topicId` on resolve.
`kind`	Filter or field	`SCALAR`	Feed value kind. Facetable on the list endpoint.
`scope`	Filter or field	`global`, `identity`, `asset`, `other`	What the feed prices. Facetable on the list endpoint.
`isActive`	Filter or field	boolean	Whether the feed is currently active. Facetable on the list endpoint.
`decimals`	Filter or field	integer	Decimal places for `answer`. Divide `answer` by `10` to the power of `decimals`.
`description`	Field	string or `null`	`<BASE> / <QUOTE>` label such as `USDT / USD`.
`latestValue`	Field	object or `null`	Most recent indexed round: `roundId`, `answer`, `observedAt`, `issuer`, `signer`. `null` before the first round.
`answer`	Field	integer string	Reported value in feed units. Apply `decimals` to read the human value.
`formattedAnswer`	Field	decimal string	Latest value already converted into human units on the latest read.
`isStale`	Field	boolean	Staleness decision: `true` when `ageSeconds` exceeds `maxAgeSeconds`.
`requirePositive`	Field	boolean	Whether the feed rejects zero and negative answers. Returned by the config read.
`driftAllowance`	Field	integer	Seconds an update timestamp may lead block time. `0` requires it at or before block time. Returned by config.
`historyMode`	Field	`LATEST_ONLY`, `BOUNDED`, `FULL`	Number of past rounds the feed retains. Returned by the config read.
`exists`	Field	boolean	Whether resolve found a registered feed for the subject and topic.
`filter[q]`	Query	string	Free-text search across feed address, subject, topic, and description on the list endpoint.
`page[limit]`	Query	integer	Page size for collection responses.
`page[offset]`	Query	integer	Offset for collection responses.
`sort`	Query	string	Sort field. Prefix with `-` for descending order, such as `sort=-registeredAt`.

Exchange rates resolves one fiat rate per currency pair on top of these feeds.
Token price resolution explains how token pricing combines base-price and currency feeds.
Operational integration patterns covers retries, readback checks, and reconciliation around API integrations.

Price feeds