On the Symphony web or desktop client, this ID can be found by clicking on the timestamp of any message in the conversation. This will open the Message Status module, where the Conversation ID can be found, as shown in the following picture.
The Conversation ID in the Symphony Web Client is in Standard Base64 encoding and need to be converted to be URLSafe. Conversation IDs returned in API responses are already URLSafe Base64 encoding.
URLSafe Base64 Conversion
To obtain the URLSafe Base64 Conversation ID:
Replace forward slashes / with underscores _
Replace pluses + with minuses -
Ignore any trailing equal signs =
For example, the URLSafe Base64 encoding oflX1hwfmQ+AK/k/a/BB0y2n///q2+0KfbdA== converts to lX1hwfmQ-AK_k_a_BB0y2n___q2-0KfbdA.