Get conversation

Start a direct message conversation with a user. If a conversation with that recipient already exists, the message is added to the existing thread. Supported platforms: X, Bluesky, Reddit, WhatsApp, SMS, and Slack. Other platforms return PLATFORM_NOT_SUPPORTED. **Slack.** Pass a workspace member id as participantId (list them with GET /v1/accounts/{accountId}/slack-members). Zernio opens the DM channel with that member and sends the message; the thread then behaves like any other Slack conversation in the inbox. The member must belong to the connected workspace. **WhatsApp.** This is the endpoint for sending an approved template message to a phone number. Provide templateName, templateLanguage, and templateParams (variable values for the text header, body and dynamic URL buttons, in that order), with the recipient phone in participantId. A template is required because WhatsApp does not permit freeform messages to open a conversation; a missing template returns TEMPLATE_REQUIRED. - Templates with media headers (image, video, document) are handled automatically: Zernio reads the approved template definition and fills the header at send time with the template's approved sample asset. To send a DIFFERENT asset per message (e.g. a distinct invoice PDF for each recipient), pass the headerMedia field with a public link (or a Meta media id); it overrides the sample for that send. - A template whose approved header format is LOCATION has no header asset to reconstruct at all: Meta only accepts the location at send time, so pass headerLocation (latitude and longitude required) whenever such a template is sent; headerMedia and headerLocation cannot both be supplied. - A button that carries its own value at send time (a copy-code button holding a Pix payment code or a coupon, a flow token) is sent with templateButtonParams, addressed by the button's index; templateParams covers text variables and dynamic URL buttons only. - CAROUSEL templates take per-card overrides via templateCards, each addressed by the card's card_index, because card body variables restart at {{1}} per card and cannot be expressed in the flat templateParams order. - Template fields are accepted on the JSON body only, not on multipart requests. For a number you already have a thread with, this sends the template into that thread, which also makes it the way to re-engage a contact after the 24-hour customer-service window has closed. Once the recipient replies (opening the 24h window), send freeform messages with the send-message endpoint (POST /v1/inbox/conversations/{conversationId}/messages). Alternatively, WhatsApp Business Accounts eligible for Meta Direct Send can open a conversation with a business-initiated utility text message and no template: pass category: 'utility' together with message (and no templateName). See the category field below. **DM eligibility (X).** Before sending, the endpoint checks if the recipient accepts DMs from your account (via the receives_your_dm field). If not, a 422 error with code DM_NOT_ALLOWED is returned. You can skip this check with skipDmCheck: true if you have already verified eligibility. **X API tier requirement.** DM write endpoints require X API Pro tier ($5,000/month) or Enterprise access. This applies to BYOK (Bring Your Own Key) users who provide their own X API credentials. **Rate limits (X only).** X's DM API enforces 200 requests per 15 minutes, 1,000 per 24 hours per connected X account, and 15,000 per 24 hours per X developer app (shared across all DM endpoints). These limits do NOT apply to other platforms. WhatsApp sends are governed by Meta's per-number messaging tiers (unique business-initiated conversations per 24 hours) and per-number throughput instead.