jira service desk rest api 400 invalid project key

TL;DR

The project key is the short uppercase code like DESK, not the project name. A 400 means the key doesn't exist on this Jira instance, is misspelled, or the API caller can't see the project. Confirm the key in Project Settings, confirm the caller's access, and send the key exactly as shown.

The query

jira service desk rest api 400 invalid project key

Use this when

• Creating service desk requests returns 400 invalid project key
• The key works in the UI but fails through the API
• A renamed project broke a working integration

Not for

• 401 unauthorized calling Jira endpoints
• 403 when the project exists but access is denied
• 404 on issue keys (different resource)

Steps

1. Read the key from Project Settings

Open the service project, go to Project Settings, Details, and copy the Key field verbatim. Keys are uppercase and short. What users call the project ('Customer Support') is the name, and the API rejects names in the key slot.

Expected output: the exact key string as Jira stores it.

2. Confirm the caller can see the project

A key that exists but is invisible to the API user also 400s. Check the project's permission scheme and confirm the integration user has Browse Projects. Test with the same credentials in the UI.

Expected output: the integration user browsing the project successfully in the UI.

3. Check for renamed or archived projects

Renaming a project can change its key, and archived projects vanish from the API. If the integration worked before, ask the Jira admin what changed and update the stored key.

Expected output: a current, active project matching your stored key.

4. Hit the project endpoint directly

GET the single-project endpoint with your key. A 200 with project details proves the key and access are fine; the 400 is then in how your code builds the request, not the key itself.

Expected output: a 200 response containing the project's name and key.

Variant phrasings

jira service desk api project key not found

Steps 1 and 2: exact key first, caller visibility second.

jira 400 bad request creating service desk ticket

Step 4 isolates whether the key or the request body is at fault.

Why it happens

Jira distinguishes the project's display name from its key, and only the key works in API paths. On top of that, Jira hides projects the caller can't browse, so a valid-but-invisible key fails exactly like a typo. The 400 is Jira saying 'no such project for you', and 'for you' is doing half the work.

Edge cases

• Cloud vs Server/Data Center: endpoint paths differ. Make sure the docs you're reading match your hosting.
• Service desk projects need the request type set too; a valid key with a bad request type id fails differently.
• Migrated projects sometimes keep old keys as aliases. Don't rely on aliases.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstJ22xdARQqUxprENNnIIKQ