---
title: "Available Census ACS variables"
method: GET
path: "/api/v1/census/variables"
tags: ["Statistical Agencies"]
---

# Available Census ACS variables

`GET /api/v1/census/variables`

List all available demographic and economic variables with codes.

## Response `200`

Catalog of ACS variable keys, codes, labels, and dataset metadata.

- EnvelopeCensusVariablesData
  - `data` CensusVariablesData, required
    - `variables` Variable[], nullable
      - `key` string, nullable — Map key or identifier.
      - `label` string, nullable — Human-readable label.
    - `count` union — Number of items in this result set.
      - integer
      - number
    - `datasets` Datasets
      - `acs1` Acs1
        - `title` string, nullable — Display title.
        - `description` string, nullable — Human-readable description.
      - `acs5` Acs1
        - `title` string, nullable — Display title.
        - `description` string, nullable — Human-readable description.
    - `source` string, nullable — Upstream data source identifier.
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header. JSON body with a stable `code` distinguishing `missing_api_key` (no header sent) from `invalid_api_key` (header sent, key not accepted); any other 401 source carries the generic `unauthorized` with its detail as `reason`. Plus `hint`. `plan` is always null on 401 - an unauthenticated request has no plan; quota exhaustion is 429, not 401.
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `502` — The upstream source answered with an error or a malformed body. `detail` carries the source, the upstream status and a retry hint.
- `503` — Upstream unreachable (typed `detail` object with source and retry hint) or the legacy blanket unavailability (string `detail`).
- `504` — The upstream source did not answer within the client deadline.

## Changes

- **2026-08-29** `18b96293341c` — 3 breaking, 5 warning, 2 info
  - added `#/components/schemas/UpstreamErrorResponse, subschema #2` to the response body `oneOf` list for the response status `503`
  - the response's body type/format changed from `object`/`` to ``/`` for status `503`
  - removed the required property `error` from the response with the `503` status
  - removed the optional property `code` from the response with the `503` status
  - …6 more
- **2026-08-28** `560e8847c7b3` — 10 breaking, 1 info
  - the response property `data/count` became optional for the status `200`
  - the response property `data/datasets` became optional for the status `200`
  - the response property `data/source` became optional for the status `200`
  - the response property `data/variables` became optional for the status `200`
  - …7 more
- **2026-08-08** `4c4530760ba1` — 12 info
  - added the optional property `code` to the response with the `401` status
  - added the optional property `code` to the response with the `429` status
  - added the optional property `code` to the response with the `503` status
  - added the optional property `hint` to the response with the `401` status
  - …8 more

[Change history](https://skmtc.dev/sugra/apis/sugra-api/changes/api/v1/census/variables/get.md)

---

[API](https://skmtc.dev/sugra/apis/sugra-api.md) · [All operations](https://skmtc.dev/sugra/apis/sugra-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/sugra/sugra-api/revisions/87582f2e0110/schema)