---
title: "Inspect a metadata index"
method: GET
path: "/v3/{ledgerName}/indexes/{canonicalId}/inspect"
tags: ["Indexes"]
---

# Inspect a metadata index

`GET /v3/{ledgerName}/indexes/{canonicalId}/inspect`

## Request

- Base URL: `http://localhost:9000`
- URL: `http://localhost:9000/v3/{ledgerName}/indexes/{canonicalId}/inspect`
- Auth: one of:
  - HTTP bearer
  - none

Scans a metadata index and returns distinct values, facets (value + count),
or a summary (cardinality, min/max, existence counts). The index must be
in READY state. Only metadata indexes are inspectable (builtin indexes
return 400). Requires `ledger:read` scope.

## Path parameters

- `ledgerName` string, required
- `canonicalId` string, required

## Query parameters

- `mode` 'summary' | 'distinctValues' | 'facets'
- `pageSize` integer
- `cursor` string: Page token of a paged list. Clients normally pass back the `next` or `previous` value of a previous response verbatim; building one by hand is supported. A token is base64url (unpadded, RFC 4648 §5) of the JSON object `{"key": <string>, "back": <bool>}`. Both fields are omitted when empty, and unknown fields are rejected. `key` is a position in the endpoint's textual form: - transactions: decimal transaction id - logs: decimal ledger-local log id - audit entries: decimal audit sequence - accounts: address - ledgers and numscripts: name - signing keys: key id - prepared queries: decimal id for TRANSACTIONS and LOGS targets, address for ACCOUNTS - index inspection: base64url of the encoded metadata value Both directions exclude the key and return rows in the requested order (`reverse` included): - `{"key": K}` serves the rows strictly after K; - `{"key": K, "back": true}` serves the page that ends strictly before K; - `{"back": true}` serves the last page; - an absent or empty token, or `e30` (`{}`), serves the first page. On a forward page, `next` is set when a further row follows the page, and `previous` whenever the request carried a key. On a back page, `previous` is set when a further row precedes the page, and `next` whenever the request carried a key. A first page therefore has no `previous`, and the last page requested with `{"back": true}` has no `next`. A malformed token, or a key that is not a valid position for the endpoint, is rejected with 400 `INVALID_REQUEST`.

## Headers

- `X-Consistency` 'linearizable' | 'stale'

## Response `200`

Index inspection result

- object
  - `data` union, required
    - InspectSummaryResponse
      - `cardinality` integer, required: Number of distinct values
      - `min` unknown
      - `max` unknown
      - `entitiesWithKey` integer, required: Number of entities that have this metadata key set (non-null)
      - `entitiesWithNull` integer, required: Number of entities with a null value for this key
    - InspectDistinctValuesResponse
      - `values` unknown[], required: Distinct values in sorted order
        - unknown
      - `hasMore` boolean, required: Whether more values are available; set iff `nextCursor` is
      - `nextCursor` string: Page token of a paged list. Clients normally pass back the `next` or `previous` value of a previous response verbatim; building one by hand is supported. A token is base64url (unpadded, RFC 4648 §5) of the JSON object `{"key": <string>, "back": <bool>}`. Both fields are omitted when empty, and unknown fields are rejected. `key` is a position in the endpoint's textual form: - transactions: decimal transaction id - logs: decimal ledger-local log id - audit entries: decimal audit sequence - accounts: address - ledgers and numscripts: name - signing keys: key id - prepared queries: decimal id for TRANSACTIONS and LOGS targets, address for ACCOUNTS - index inspection: base64url of the encoded metadata value Both directions exclude the key and return rows in the requested order (`reverse` included): - `{"key": K}` serves the rows strictly after K; - `{"key": K, "back": true}` serves the page that ends strictly before K; - `{"back": true}` serves the last page; - an absent or empty token, or `e30` (`{}`), serves the first page. On a forward page, `next` is set when a further row follows the page, and `previous` whenever the request carried a key. On a back page, `previous` is set when a further row precedes the page, and `next` whenever the request carried a key. A first page therefore has no `previous`, and the last page requested with `{"back": true}` has no `next`. A malformed token, or a key that is not a valid position for the endpoint, is rejected with 400 `INVALID_REQUEST`.
      - `previousCursor` string: Page token of a paged list. Clients normally pass back the `next` or `previous` value of a previous response verbatim; building one by hand is supported. A token is base64url (unpadded, RFC 4648 §5) of the JSON object `{"key": <string>, "back": <bool>}`. Both fields are omitted when empty, and unknown fields are rejected. `key` is a position in the endpoint's textual form: - transactions: decimal transaction id - logs: decimal ledger-local log id - audit entries: decimal audit sequence - accounts: address - ledgers and numscripts: name - signing keys: key id - prepared queries: decimal id for TRANSACTIONS and LOGS targets, address for ACCOUNTS - index inspection: base64url of the encoded metadata value Both directions exclude the key and return rows in the requested order (`reverse` included): - `{"key": K}` serves the rows strictly after K; - `{"key": K, "back": true}` serves the page that ends strictly before K; - `{"back": true}` serves the last page; - an absent or empty token, or `e30` (`{}`), serves the first page. On a forward page, `next` is set when a further row follows the page, and `previous` whenever the request carried a key. On a back page, `previous` is set when a further row precedes the page, and `next` whenever the request carried a key. A first page therefore has no `previous`, and the last page requested with `{"back": true}` has no `next`. A malformed token, or a key that is not a valid position for the endpoint, is rejected with 400 `INVALID_REQUEST`.
    - InspectFacetsResponse
      - `facets` InspectFacet[], required: Facets sorted by value
        - `value` unknown, required
        - `count` integer, required: Number of entities with this value
      - `hasMore` boolean, required: Whether more facets are available; set iff `nextCursor` is
      - `nextCursor` string: Page token of a paged list. Clients normally pass back the `next` or `previous` value of a previous response verbatim; building one by hand is supported. A token is base64url (unpadded, RFC 4648 §5) of the JSON object `{"key": <string>, "back": <bool>}`. Both fields are omitted when empty, and unknown fields are rejected. `key` is a position in the endpoint's textual form: - transactions: decimal transaction id - logs: decimal ledger-local log id - audit entries: decimal audit sequence - accounts: address - ledgers and numscripts: name - signing keys: key id - prepared queries: decimal id for TRANSACTIONS and LOGS targets, address for ACCOUNTS - index inspection: base64url of the encoded metadata value Both directions exclude the key and return rows in the requested order (`reverse` included): - `{"key": K}` serves the rows strictly after K; - `{"key": K, "back": true}` serves the page that ends strictly before K; - `{"back": true}` serves the last page; - an absent or empty token, or `e30` (`{}`), serves the first page. On a forward page, `next` is set when a further row follows the page, and `previous` whenever the request carried a key. On a back page, `previous` is set when a further row precedes the page, and `next` whenever the request carried a key. A first page therefore has no `previous`, and the last page requested with `{"back": true}` has no `next`. A malformed token, or a key that is not a valid position for the endpoint, is rejected with 400 `INVALID_REQUEST`.
      - `previousCursor` string: Page token of a paged list. Clients normally pass back the `next` or `previous` value of a previous response verbatim; building one by hand is supported. A token is base64url (unpadded, RFC 4648 §5) of the JSON object `{"key": <string>, "back": <bool>}`. Both fields are omitted when empty, and unknown fields are rejected. `key` is a position in the endpoint's textual form: - transactions: decimal transaction id - logs: decimal ledger-local log id - audit entries: decimal audit sequence - accounts: address - ledgers and numscripts: name - signing keys: key id - prepared queries: decimal id for TRANSACTIONS and LOGS targets, address for ACCOUNTS - index inspection: base64url of the encoded metadata value Both directions exclude the key and return rows in the requested order (`reverse` included): - `{"key": K}` serves the rows strictly after K; - `{"key": K, "back": true}` serves the page that ends strictly before K; - `{"back": true}` serves the last page; - an absent or empty token, or `e30` (`{}`), serves the first page. On a forward page, `next` is set when a further row follows the page, and `previous` whenever the request carried a key. On a back page, `previous` is set when a further row precedes the page, and `next` whenever the request carried a key. A first page therefore has no `previous`, and the last page requested with `{"back": true}` has no `next`. A malformed token, or a key that is not a valid position for the endpoint, is rejected with 400 `INVALID_REQUEST`.

## Other responses

- `400`: Bad request
- `401`: Authentication required (missing or invalid JWT token)
- `403`: Insufficient permissions (missing required scope)
- `404`: Not found
- `405`: Method not allowed
- `500`: Internal server error
- `503`: Service unavailable — the server cannot serve the request right now but an immediate retry can succeed. The `errorCode` field discriminates the cause: `NO_LEADER` (no elected Raft leader), `CACHE_HORIZON_EXCEEDED` (admission snapshot too old, retry against a fresh one), `UNAVAILABLE` (an internal forwarded stream was torn down mid-transfer), or the reason of any domain error of the unavailable kind (e.g. `INDEX_BUILDING`).

## Changes

- **2026-11-03** `f5e817eca038`: 1 info
  - api operation id `inspectIndex` removed and replaced with `v3InspectIndex`
- **2026-10-08** `3da23d327316`: 2 info
  - added the media type `text/plain` for the response with the status `401`
  - added the media type `text/plain` for the response with the status `403`
- **2026-10-08** `b3ee1959d86a`: 1 info
  - added the new optional `header` request parameter `X-Consistency`
- **2026-10-08** `21be46727a2f`: 2 info
  - added the optional property `data/oneOf[#/components/schemas/InspectDistinctValuesResponse]/previousCursor` to the response with the `200` status
  - added the optional property `data/oneOf[#/components/schemas/InspectFacetsResponse]/previousCursor` to the response with the `200` status
- **2026-10-06** `6413bb242a30`: 2 warning
  - removed the optional property `data/oneOf[#/components/schemas/InspectDistinctValuesResponse]/previousCursor` from the response with the `200` status
  - removed the optional property `data/oneOf[#/components/schemas/InspectFacetsResponse]/previousCursor` from the response with the `200` status

[Operation history](https://skmtc.dev/formancehq/apis/ledger-api/changes/v3/:ledgerName/indexes/:canonicalId/inspect/get.md)

---

[API](https://skmtc.dev/formancehq/apis/ledger-api.md) - [All operations](https://skmtc.dev/formancehq/apis/ledger-api/llms.txt) - [OpenAPI document](https://skmtc.dev/formancehq/apis/ledger-api/revisions/f5e817eca038?raw)