Inbox API: agents draft, people approve

The inbox API lets an agent read the comments, mentions and reviews on your accounts and propose replies. Nothing is posted until a person approves the reply.

It is being rolled out gradually and returns 404 until it is enabled for your workspace.

Networks

Network	Status
Bluesky	Available
Mastodon	Available
LinkedIn Pages	Available
Google Business Profile (reviews)	Available
Facebook Pages, Instagram	After Meta approves the engagement permissions (see network permissions)
X	Not planned: X charges for every read

The flow

1. Read. GET /{workspaceUuid}/inbox/conversations lists conversations with the latest message, newest activity first. Filter with status, unread, account_id, provider, sentiment, ai_label and since. GET .../inbox/conversations/{id} returns the last 50 messages.
2. Draft. POST .../inbox/conversations/{id}/drafts with {"body": "..."} stores a pending draft. By default it replies to the latest incoming message; send in_reply_to (a message id) to pick another. Needs the write ability.
3. Approve. A workspace admin or member opens Reply drafts at https://postboost.co/app/{workspaceUuid}/inbox-drafts, edits the text if needed, and approves or rejects it. Approval sends the reply. A different API key with the publish ability can also call POST .../inbox/drafts/{id}/approve or /reject.
4. Check. GET .../inbox/drafts/{id} shows status: pending, approved, rejected, sent, or failed with an error.

Rules

• The API key that wrote a draft cannot approve it (403, code: self_approval). Give your agent a key with read and write only.
• A draft is sent at most once. Approving, editing or deleting a draft that was already reviewed returns 409.
• Reply length limits: Bluesky 300 characters, Mastodon 500, LinkedIn 1250, Google 4000.
• Viewers cannot use the inbox API.
• PATCH .../inbox/conversations/{id} marks a conversation open or resolved, and read or unread.
• The MCP servers do not offer approve or reject tools: a person approves.

Notifications

• Webhooks: subscribe to inbox.draft.created (a draft is waiting) and inbox.draft.sent (an approved reply was posted). data is the draft as GET .../inbox/drafts/{id} returns it.
• Email: once a day, workspace admins get one digest listing drafts that have waited more than 4 hours, with a link to Reply drafts. No email is sent when nothing is waiting.