Skip to main content
Your LinkedIn inbox is not read live. The platform keeps its own copy of every thread and message, built by a sync through the account’s own browser and topped up by a realtime signal.

​
Two inboxes, synced separately

The regular messenger and the Sales Navigator inbox are separate surfaces with their own threads and their own clocks. Every thread carries a messenger_type. SN threads sync only once the platform detects the subscription (premium_check, its own surface, every 360 minutes), which has to run before the Sales Nav Conversations row appears. A basic-messenger verb on an SN thread answers 422 messenger_type_mismatch.

​
What the initial backfill imports

Onboarding walks a fixed ordered set of surfaces (connections, connection requests, connection invitations, the regular inbox, the premium check, the Sales Navigator inbox, then the profile snapshot) and the account unlocks when it finishes. Every thread is imported, since the run pages to an empty page. Not every message is.
The message drain runs inline inside the conversations sync itself, while the account is still onboarding, and fetches exactly one page of the 50 newest messages per thread, then stops; it does not page backwards. A 400-message thread arrives with its 50 most recent ones, and older history stays outside the platform: POST /api/linkedin-messages/get-my-latest refreshes the newest page of up to 100 messages and stops there.
During onboarding the self_account_sync daily budget is raised from 200 to 1000 calls per day; the first profile snapshot taken after onboarding completes recomputes it back down to 200. A first-time backfill runs to completion whatever hours are configured; only recurring syncs wait for the window: an inbox sync spends that budget and nothing else.

​
How often each surface re-syncs

Three things change the effective interval: your per-account setting on the Account Sync tab, the sync window (a run due outside the configured hours parks with schedule:closed until it reopens), and the free plan floor.
On the free plan every surface is floored to once per 1440 minutes (daily): the effective interval is the larger of the two. Free plan accounts also get no realtime push, so a reply can sit for up to a day. Initial backfills are exempt from the floor.
A recurring run is not a full re-read: it walks the directory newest first and stops once a page holds 10 threads it already knows, and regular-inbox pages are capped at 25 threads by the browser plugin (the Sales Navigator sweep pages at 100). Only threads whose event count or last activity moved ahead of the stored copy are read.

​
Realtime push, and what it does not do

While the account’s browser runs, the plugin listens to LinkedIn’s own realtime stream and tells the platform when a message arrives: end to end, a received message reaches the linkedin-messages.received webhook in about 8 seconds, against the 180 minute sweep. The push carries identifiers only and never writes a message row. For a thread the platform already knows it schedules a refresh of that one thread, read through the account’s own browser, and the rows land tagged source='push'. For a thread it has never seen it falls back to an account-wide conversations refresh, whose rows are tagged source='sync' like the sweep’s: the webhook still fires, but the live Inbox screen does not update until the sweep. Signals it drops: The rest are environmental: disabled (off platform-wide), unhandled_type (typing indicator or read receipt), no_linkedin_account, account_not_found and dispatch_failed. A dropped signal is never a lost message: the worst case is that it appears on the next sweep instead of within seconds. Your own reply typed in the LinkedIn UI is always in that class, and lands on the sweep as type='outbox' with automation='synced': discovered, not sent.

​
Force a refresh now

A head refresh reads the newest page of one thread or account synchronously and returns the rows themselves; use it in almost every case. A full sync reconciles the head of the directory in the background and returns a sync run to poll; like every recurring run it stops once a page holds 10 threads it already knows, so it will not reach an old thread that is missing locally. Only a sync reset re-walks the directory end to end.
curl
The response carries a refresh block with counters and a stop_reason of overlap, covered, page_cap or exhausted. A head refresh never stamps the account’s sync clock and never emits linkedin-conversations.sync-completed, so it does not postpone the next drain.
Every head refresh page and every background message pull spends one call from the account’s self_account_sync budget: 200 calls per day, with a 6 second pacing delay and bursts of 5. When it is spent, reads answer 429 rate_limited with limit_type: "self_account_sync" and a retry_after, and parked runs resume at the next daily reset or when the limit is raised. See smart limits and warmup.

​
Why a message may not appear yet

Three timestamps answer most of it: last_activity_at (newest activity LinkedIn reports), last_stored_message_at (newest message stored) and last_message_sync_at (last pull). Activity newer than stored means the thread is already flagged and the next run drains it. Otherwise:
  1. The account is still onboarding. The drawer shows Initial sync in progress and head refreshes answer 429 rate_limited with context.reason: "initial_sync_pending".
  2. A sync is already running for that surface. A second one does not queue: it answers 429 rate_limited with reason: "sync_in_progress" and the working sync_run_sid to poll.
  3. The sync budget is spent or held. The run shows a wait_reason starting with limit: (limit:daily_saturation, limit:held, limit:linkedin_quota_hit, limit:delay_not_elapsed). Raise the Self account sync limit on Smart Limits with reset hold to resume them all now.
  4. The browser is down or logged out. Sync verbs still enqueue and hand back a sync_run_sid; the run then parks with a browser: wait_reason and retries roughly 30 minutes out, while a head refresh answers 503 service_unavailable. Budget parks wake on a raised limit, browser parks wait for their retry.
  5. It is outside the sync window. The run carries wait_reason: "schedule:closed" and a next_attempt_at set to the next opening. Widen the window or head-refresh now.
  6. The message is older than the newest 50 in its thread. No sweep backfills older history: call get-my-latest on that thread to pull the newest page of up to 100 messages.
  7. It was a push drop and the sweep has not run. Your own reply typed on LinkedIn, a duplicate signal, a burst above 10 refreshes a minute and free plan accounts all skip the fast path: the wait is then up to 180 minutes (regular), 120 (Sales Navigator), 1440 (free plan).
  8. Still nothing? Send support the account sid (ln_ac_…), the Account Sync row with its status and next due time, and the sync run sid (ln_sy_…) with its wait_reason.
A sync run never has a “failed” status: runs go pending, then in_progress, then completed or cancelled. One stuck at in_progress is almost always waiting, so read its wait_reason and next_attempt_at.
Copyable prompt for your AI agent:Diagnose why a LinkedIn message is missing from my GTM API inbox copy, for the ln_ac_ sid I give you. Search linkedin-account-sync-runs for it, sync_type conversations, newest first, and report the latest run’s status, wait_reason and next_attempt_at. Then search linkedin-conversations for the thread and compare last_activity_at with last_stored_message_at; if activity is newer, call get_my_latest_linkedin_messages on that sid with page_size 50 and report the refresh block. Only full-sync if threads are missing.

​
Reading the stored copy

A message carries type (inbox or outbox), automation (auto, manual, connect or synced) and linkedin_type (message, inmail or connection_note). Messages are append-only on both surfaces: no edit, no delete, no unsend, no recall. There are no read receipts and no open tracking, and marking a thread read changes the state on LinkedIn only. There is no export button and no CSV. linkedin-messages/search and linkedin-conversations/search page by cursor and touch neither the browser nor the budget (filters and sorts are in the API reference), and a conversation from another workspace answers 403 wrong_team, not 404. Webhooks deliver linkedin-messages.received, .sent and .send-failed, plus linkedin-conversations.created and .sync-completed.
A send that fails never creates a message row: the failure lands on the activity log and is emitted as linkedin-messages.send-failed carrying the linkedin_account_sid, the linkedin_conversation_sid and an error_code (the activity-log sid is not in the payload; find the row by account and time). If a send times out and you are unsure whether it went through, search messages on that conversation with type: "outbox" and sent_at after the attempt. A blind retry can double-send.
A sync reset with conversations or sales_navigator_conversations selected soft-deletes every stored conversation for that account and surface, and all of their messages, in one transaction. The next sync rebuilds the directory, resurrecting the same rows (same sid) as it re-observes them, so resurrected threads fire no linkedin-conversations.created and only genuinely new ones do, and it re-drains the newest 50 messages per thread; anything you fetched deeper stays soft-deleted and out of results. Nothing else removes a thread: one that disappears on LinkedIn keeps its stored copy.