> ## Documentation Index
> Fetch the complete documentation index at: https://docs.secapi.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# GET /v1/companies/subsidiaries

> Retrieve subsidiaries disclosed in an issuer's latest available 10-K Exhibit 21

Retrieve subsidiaries disclosed in an issuer's latest available 10-K Exhibit 21

<Info>
  Audience: application and coding agent.
</Info>

## Coverage and source scope

Use this route to review subsidiaries an issuer disclosed in Exhibit 21 of its latest available 10-K. The result is an extracted filing schedule, not a current legal-entity registry, complete ownership chart, or confirmation that an issuer has no other subsidiaries. An empty list can mean the selected filing lacks a usable Exhibit 21. Preserve the returned accession, filing date, and request metadata when presenting the default result; `filingUrl` is included only in `agent` view. See [filing conventions](/api-conventions) and [freshness and source evidence](/freshness-and-trust).

## Agent mode

Pass `?view=agent` to receive the compact agent shape: per-subsidiary fields (name, jurisdiction, ownershipPercent) + envelope citation fields (accessionNumber, filingDate, filingUrl). `filingUrl` is exclusive to the agent response; the default response returns accessionNumber and filingDate without it. The `lineage` metadata block is dropped. The per-item shape is already narrow, so this endpoint is an API-consistency win rather than a byte-size win — reduction is approximately **0%** but the agent envelope matches the contract exposed by every other agent-mode endpoint. See [api conventions → response formats](/api-conventions) for the full `?view=` contract.

## Canonical metadata

* `requestId`
* `traceparent`

## Example request

<RequestExample>
  ```bash theme={null}
  curl -X GET \
    -H "x-api-key: $SECAPI_API_KEY" \
    -H "secapi-version: 2026-03-19" \
    "https://api.secapi.ai/v1/companies/subsidiaries?ticker=AAPL"
  ```
</RequestExample>

## Example response

<ResponseExample>
  ```json theme={null}
  {
    "requestId": "req_2ZK8Q1W9F4M6P7R3"
  }
  ```
</ResponseExample>

## Give this prompt to your agent

<Prompt>
  Use SEC API GET /v1/companies/subsidiaries to retrieve subsidiaries disclosed in an issuer's latest available 10-K Exhibit 21. Preserve `requestId`, `traceparent` in the output. Return a concise markdown summary plus the exact structured payload fields that a downstream engineer or agent should keep using this result.
</Prompt>

## Failure posture

* treat non-2xx responses as contract-aware failures, not free-form errors
* preserve `requestId` and `traceparent` in logs and downstream reports
* if provenance or freshness metadata is present, return it unchanged so trust is not lost in the handoff