80405: Participant Sid Invalid

This warning appears when you pass an invalid Participant SID to a Proxy request. Proxy Participant resources use SIDs with the KP prefix, and Twilio SIDs are 34-character identifiers made up of a two-letter prefix followed by 32 hexadecimal characters.

• The Sid or ParticipantSid value does not use the required KP prefix.
• The Participant SID is not 34 characters long.
• The value contains invalid characters, such as non-hexadecimal characters or extra whitespace.
• You passed a different resource SID, such as a KS Service SID, KC Session SID, or KI Interaction SID, where a Participant SID is required.
• You are not using the Participant SID returned when you created or fetched the Proxy Participant resource.

• Use the Participant SID returned by the Proxy Participant resource before making follow-up requests.
• Validate the Participant SID format before sending the request. Use the pattern ^KP[0-9a-fA-F]{32}$.
• Confirm that you pass the Participant SID only in endpoints that require a participant resource, such as /Participants/{Sid} or /Participants/{ParticipantSid}/MessageInteractions.
• Keep ServiceSid, SessionSid, and ParticipantSid in separate parameters and do not substitute one resource SID for another.
• If you are sending a message through Proxy, create or list the session participants first, then use the correct ParticipantSid for the target participant.

• Proxy Participant API reference
• Sending Messages with Proxy
• What is a String Identifier (SID)?