For developers and technical teams building on LinkedIn

LinkedIn outreach API for developers.

Manage campaigns, sequences, sender accounts, inboxes and real-time events through one API, on infrastructure that handles pacing, retries, safeguards and account health.

Service status
POST /campaigns
curl -X POST https://app.swarmhit.com/api/v1/campaigns \
  -H "Authorization: Bearer swh_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Q3 Founders",
    "linkedinAccountIds": ["aCc123", "aCc456"],
    "sequence": { "steps": [
      { "type": "visit_profile", "nextDelayHours": 24 },
      { "id": "invite1", "type": "invite",
        "config": { "note": "Hi {{firstName}}...",
                    "fallbackNote": "Hi there..." } },
      { "type": "message", "parent": "invite1", "branch": "yes",
        "config": { "text": "Thanks for connecting..." } }
    ] }
  }'

200 OK, then events stream back to your webhook

message.received{ "data": { "message": { "text": "Thanks for reaching out..." } } }

Deliveries signed with X-Swarmhit-Signature (HMAC SHA-256)

Architecture

You call one API. The sequencer does the LinkedIn part.

Your product talks REST and receives signed webhooks. Everything between your request and a safe action on a real LinkedIn account is Swarmhit's job.

Weighing building this layer yourself? Our guide to building a LinkedIn outreach tool walks through what it takes.

Your product

SaaS, agent or internal workflow

POST /campaigns

on: message.received

REST
webhooks

Swarmhit sequencer

api/v1

Handled here, not in your code

Rate limits and capsSessions and checkpointsSender cooldownsAccount safeguardsCampaign stateWebhook delivery

LinkedIn accounts

Sending

Your senders on dedicated proxies

invite · message · InMail

per-sender limits, enforced

The API surface

Everything the platform does, your code can do.

The outreach platform and the API run on the same engine, so every resource below is the production surface, not a wrapper.

Real-time events

Your agent knows the moment something happens.

Sending is half the job. Swarmhit pushes events back to your agent as they happen on LinkedIn, so it can decide the next move in real time: reply instantly, change the plan, escalate to a human, or update your CRM.

Every delivery is signed with HMAC SHA-256 and logged, so you can verify, inspect and replay what your endpoint received.

webhook deliveries

live
eventconnection.accepted
eventmessage.received
eventlead.status_changed

Signed with X-Swarmhit-Signature, delivered with full context.

Built for production

The boring parts are already done.

Bearer API keys

swh_live_ keys against the versioned base URL, app.swarmhit.com/api/v1.

Idempotent sends

Idempotency-Key header on every send endpoint, so retries never double-send.

Signed webhooks

Every delivery signed with HMAC SHA-256 via X-Swarmhit-Signature.

Delivery log

Every webhook delivery recorded with its exact payload, filterable and replayable.

Structured errors

One error shape, { "error": { "status", "message" } }, from 400 to 500.

Rate limits

Explicit 429 responses when you push past the limits.

Pagination

limit, offset and paging metadata on every list endpoint.

Multi-tenant by design

One organization key can act as any workspace in your organization.

Why not a generic API layer

The LinkedIn layer is the hard part. Ours is already built.

Generic providers hand you raw LinkedIn actions and keep the hard part on your plate. For the full landscape, see our dated comparison of LinkedIn outreach APIs.

Build on raw APIs

  • Months of building and debugging raw actions
  • LinkedIn business logic yours to design, build, and maintain
  • Rate limits and account safety learned in production
  • Poll endpoints and reconcile state yourself
  • Scaling senders is your problem
  • White-label partial, if offered at all
  • API costs stack on top of your build cost
Production-ready in about a week

Swarmhit

  • Campaign logic, throttles, and safeguards built in
  • Invites, messages, InMail, withdrawals, reconnects pre-built
  • Dedicated proxies and human-like patterns for every sender
  • Events pushed to your webhook the moment they happen
  • Built for fleets of senders from day one
  • Complete white-label, your brand end to end
  • Competitive per-seat pricing, scoped on a call
Book a call

Integration models

Three ways to build on Swarmhit.

Build with our infrastructure

API access

Integrate the API directly into your product and build your own frontend. Campaign logic, throttling, retries and safeguards come already built in.

Maximum control. For product teams.

api session

POST /campaigns → 200 OK

event message.received · pushed to your webhook

throttles, retries, safeguards: handled

Launch in days

White-label

Offer LinkedIn outreach under your own brand and domain with almost no engineering. Swarmhit runs the infrastructure, accounts and safety systems behind the scenes.

Fastest launch. For agencies and platforms.

app.yourbrand.com

Q3 outbound · 12 senders

Live

Reply from Priya N.

Interested

powered by Swarmhit, invisible to your customers

Built together

Hybrid

Combine API access with white-label components, plus custom engineering to match your product. Scoped and priced separately because it involves dedicated engineering time.

Flexible integration. For complex products.

Your product
custom layer shipped
Swarmhit infrastructure

Ship LinkedIn outreach without building the LinkedIn layer.

Pricing depends on sender volume, integration model, and your product requirements. We'll scope everything together during a short technical call.

FAQ

Questions, answered.