Authentication required, not authenticated

Linear API · GET /graphql · HTTP 401 AUTHENTICATION_ERROR

Status: ✅ verified:server:prod · first seen 2026-10-31 · last confirmed 2026-10-31 · 1 confirmation from 1 vantage

An Authorization value that is not a valid key returns exactly what no key returns: HTTP 401 AUTHENTICATION_ERROR "Authentication required, not authenticated". Linear has no separate invalid-key error, so this 401 does not tell a wrong key from a missing one.

What to do

1. Send header Authorization = the account setting api_key.

Example

What probe af:linear:probe:invalid-key sends (prod) and what it checks in the answer; apifacts-invalid-key is a deliberately wrong key.

Step 1 → HTTP 401:

GET https://api.linear.app/graphql?query=%7B+viewer+%7B+id+%7D+%7D
Authorization: apifacts-invalid-key
Content-Type: application/json

Step 2 → HTTP 401:

GET https://api.linear.app/graphql?query=%7B+issue%28id:+%22agent-facts-no-such-issue%22%29+%7B+id+%7D+%7D
Authorization: apifacts-invalid-key
Content-Type: application/json

Response (only what the probe asserts; other fields omitted):

HTTP 401

{
  "errors": [
    {
      "extensions": {
        "code": "AUTHENTICATION_ERROR"
      }
    }
  ]
}

In your code

Fix 1:

headers["Authorization"] = YOUR_API_KEY

Dimensions

env: prod · plan: any · region: any · account_state: anonymous

Evidence

Probe af:linear:probe:invalid-key (declarative, source)

Observations: none from reporters yet.

Related errors

• Errors are a GraphQL body {errors: [{message, extensions: {code, type, statusCode, userError, userPresentableMessage, http}}]} sent with a matching HTTP status; the vendor code is errors[0].extensions.code and the request id comes in the x-request-id header. · GET /graphql · HTTP 401
• Authentication required, not authenticated · GET /graphql · HTTP 401 AUTHENTICATION_ERROR
• This operation has been blocked as a potential Cross-Site Request Forgery (CSRF). Please either specify a 'content-type' header (with a type that is not one of application/x-www-form-urlencoded, multipart/form-data, text/plain) or provide a non-empty value for one of the following headers: x-apollo-operation-name, apollo-require-preflight · GET /graphql · HTTP 400 BAD_REQUEST

Machine access

Match signature (what check() matches): authentication required, not authenticated

curl -s https://apifacts.dev/v0/check \
  -H 'content-type: application/json' \
  -d '{"target":{"method":"GET","url":"https://api.linear.app/graphql"},"error":{"status":401,"body_excerpt":"authentication required, not authenticated"}}'

YAML: facts/linear/invalid-api-key-same-as-missing.yaml

Data: CC BY 4.0 · apifacts registry · This page is generated; edit the YAML, not the page.