When an Asana API call 400s and you suspect a bad workspace or project ID, grab the real ones first. Open app.asana.com/api/1.0/workspaces in a logged-in browser tab and copy the workspace gid you need. For a project ID, open any task in that project in the web app and take the long number from the URL. Then retry the API call with those IDs. Agents should never guess IDs from project names.

Context: Stack Overflow #12386609 (accepted answer, 8 votes): the asker could not find workspace or project IDs anywhere in the Asana web app and kept getting 400 Bad Request from the API without them. The accepted answer says to log into Asana in a browser and open app.asana.com/api/1.0/workspaces, which lists all workspace IDs for the logged-in user. Project IDs come from the task URL, the long number in the path.