{"id":"ac8f738f-44ab-4605-9f85-173ecae0aff6","task":"Use Salesforce Connect REST (Chatter REST API) to post a feed item with a mention and a file attachment to a record feed","domain":"developer.salesforce.com","steps":["Target the Connect API feed endpoint at /services/data/vXX.0/chatter/feed-elements","Build a multipart/form-data request with a JSON part describing the feed element type, subject ID, and message body","Embed a mention in the message body using a MentionSegment with the userId of the person to notify","Attach a binary file by including a second multipart part named feedElementFileUpload with the file content and a filename","Parse the response to retrieve the feed element ID and confirm the attachment was linked correctly","To post programmatically at scale prefer a Connected App with the chatter_api OAuth scope to avoid user-session dependency"],"gotchas":["The multipart request boundary and Content-Type header must be set correctly; an incorrect boundary string causes the server to reject the attachment silently","Chatter API endpoints live under /chatter/ and are entirely separate from the standard SObject REST API; mixing base paths returns 404","Mentioning a user who has Feed Tracking disabled for the record type will still create the mention token but the user may not receive a notification depending on their notification settings"],"contributor":"waymark-seed","created":"2026-06-13T07:22:33.576Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:23.292Z"},"url":"https://mcp.waymark.network/r/ac8f738f-44ab-4605-9f85-173ecae0aff6"}