CampaignStack with Instantly: LinkedIn first, then the email sequence you already run

Most agencies already have Instantly warmed up, with inboxes, domains and sequences that took months to build. Nobody should have to move those. CampaignStack finds the person, scores them, runs the LinkedIn side, and hands the lead to an Instantly campaign as one step in the workflow. A reply, a bounce or an unsubscribe in Instantly flows back and changes what CampaignStack does next.

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What Instantly owns

Cold email at volume. The inbox pool, the warm-up, the rotation across domains, deliverability, the sequence editor and the unibox the team reads replies in. If the client's email program lives in Instantly, it should keep living there; the inboxes carry a reputation that does not transfer.

What CampaignStack owns

Who goes into the sequence and when. Instantly starts from a list you upload; it has no idea that a lead commented on a competitor's post yesterday, accepted a connection this morning or replied on LinkedIn ten minutes ago. CampaignStack sources on those signals, scores every lead against the campaign's ICP, runs the LinkedIn steps inside per-account budgets, and adds the lead to the Instantly campaign at the point in the graph you choose, with the reply on either channel cancelling the rest.

Side by side

Where each side attaches

What Instantly does alone, and what changes once the two are connected.

	Instantly alone	With CampaignStack
Leads into a campaign	A CSV upload or a Zap into a campaign, with every lead starting on day one.	An add-to-sequence step in the workflow adds the lead the moment it reaches that step: after a connection is accepted, after a LinkedIn message went unanswered, or straight away.
Replies and bounces	Visible in the unibox; anything else running for that person does not know.	Instantly's webhook reports the reply, bounce or unsubscribe back; the lead router cancels the queued LinkedIn touches and routes the replied exit. An hourly reconcile catches missed deliveries.
Email addresses	SuperSearch enrichment, billed in your Instantly credits.	The same SuperSearch runs as a provider in the contact enrichment step, after the Contact Finder or instead of it, so a lead sourced on LinkedIn has an address before it reaches the sequence.
Lists without sending	Lead lists you attach to a campaign later.	An add-to-list step drops the lead into an Instantly list with no outreach started, for the client who wants to press send themselves.

Setup

Set it up

One API key from Instantly, one paste in CampaignStack, one step in the workflow. The webhook is registered for you at connect time.

Create an API key in Instantly

In Instantly, open Settings, then Integrations, then API Keys, and create one. Name it CampaignStack and give it the all:all scope; the hand-off needs leads:create and campaigns:read, the webhook needs its own. Copy the key.

Connect it in CampaignStack

Open the workspace, then Integrations, then Connect on the Instantly card, and paste the key. The connect validates it against Instantly and registers the reply, bounce and unsubscribe webhook on your Instantly workspace. Disconnecting removes the webhook again.

Add the hand-off step

In the workflow editor, add an Add to sequence step where the lead should enter email, and pick the Instantly campaign from the dropdown; active campaigns first, paused and draft ones selectable so you can wire a campaign before starting it. Adding the same email twice is a silent, idempotent success. A lead without an email is skipped and the workflow moves on.

# The hand-off step, as the workflow stores it
{
  "type": "integration:add_to_sequence",
  "config": {
    "provider": "instantly",
    "campaignId": "<Instantly campaign id>",
    "skipIfInWorkspace": false,
    "blockOnFailure": false
  }
}

Let the events come back

Nothing to configure. Each hand-off is recorded, so when Instantly reports an event for that lead, CampaignStack knows which workflow it belongs to. The events and what they do are listed below; the same operations are MCP tools for an agent holding a user key.

reply_received   -> lead marked replied, queued touches cancelled
email_bounced    -> email status set to bounced
lead_unsubscribed-> lead excluded from further sends
# Delivered by Instantly's webhook; an hourly reconcile catches the ones that were not.

campaignstack_connect_instantly        { workspaceId, apiKey }
campaignstack_list_external_sequences  { workspaceId, provider: "instantly" }
campaignstack_add_lead_to_sequence     { workspaceId, provider: "instantly", leadId, campaignId }
campaignstack_add_lead_to_external_list{ workspaceId, provider: "instantly", leadId, listId }
campaignstack_enrich_lead_contact_info { workspaceId, leadId, provider: "instantly" }

01 · One field, two endpoints

Why the step uses the single-lead endpoint

Instantly has a bulk endpoint and a single-lead endpoint, and their campaign field is spelled differently. Send the bulk endpoint's name to the single-lead one and Instantly creates an orphan lead in the workspace, outside any campaign, without an error. The step uses the single-lead endpoint with the right field, and reports an already-present lead as a success rather than a failure, because the second add is exactly what a retry looks like.

02 · Failure is a note, not a stop

What happens when Instantly says no

By default the step never fails the lead. A revoked key flips the integration to an error state with a reconnect prompt and the lead completes with a note; a rate limit defers the step and honours Retry-After; an exhausted Instantly quota is a note. Turn on Block on failure for a campaign where the email step is the whole point, and those become failures you see in the queue.

Frequently asked questions

Does CampaignStack send through my Instantly inboxes?

No. It adds the lead to your campaign; Instantly sends from its own inboxes, on its own schedule, with its own limits. CampaignStack's own email sending, through a connected Gmail account, is a separate step you can use instead.

Does a reply on LinkedIn stop the Instantly sequence?

Instantly's own stop-on-reply only hears email replies. A LinkedIn reply cancels the queued CampaignStack touches; to stop the Instantly sequence too, put the hand-off after the LinkedIn steps, or react to the replied exit with a webhook step to a Zap that pauses the lead.

Which Instantly plan do I need?

The API is available on Instantly's paid plans; the hand-off, webhook and SuperSearch calls are ordinary API calls on your key. CampaignStack charges nothing for the step.