Disclosure and how this list works
Kiin runs this stack for clients and we say which tools we use. Nobody on this list pays us and there are no affiliate links. Every tool is scored on the same three questions: does it accept a signal or contact in by webhook or API, does it expose the fields you need out, and can it suppress a person everywhere when they reply. Those three answers decide whether a tool works in a signal-based system; feature lists do not.
The list is organised by layer, not by rank, because the layers are not interchangeable: a detection tool cannot sequence and a sequencer cannot detect. Our own stack — Trigify → Clay → HeyReach and Aimfox on LinkedIn, Instantly and Smartlead on email → Slack → the client's CRM — is how Kiin's GTM outbound service is built, and it is disclosed as such where it comes up. If you want the concepts before the tools, start with what signal-based outbound is.
The three layers of a signal-based outbound stack
| Layer | Job | Tools on this page | What to check |
|---|---|---|---|
| 1. Detection | See the signal — an engagement, a visit, a job change, a round | Trigify, Phantombuster, RB2B, Warmly / Dealfront / Lead Forensics, UserGems / Champify, Bombora / 6sense / G2 | Does it return a person (or a company you can resolve to one), and does it push out by webhook? |
| 2. Orchestration | Decide who qualifies, enrich them, write the merge fields, route | Clay, Cargo, n8n | ICP filter before enrichment; waterfall providers; webhook out; suppression lists from the CRM |
| 3. Sequencing | Send the touches and catch the reply | HeyReach, Aimfox, La Growth Machine, Expandi (LinkedIn); Instantly, Smartlead, lemlist, Apollo (email) | API enrolment with custom fields; reply webhook; per-account limits |
Every working stack we have seen has exactly one tool in layer two. Teams that skip it — Trigify straight into Instantly — send unqualified people templated messages and burn a domain. Teams that use two orchestration layers spend their time reconciling them.
The tools
1. Clay — the orchestration layer — every stack on this page runs through it
Clay is where signals become outreach. A table pulls the signal (a Trigify feed, a visitor-identification webhook, a job-change monitor, a funding feed), a filter removes anyone outside the ICP or on a suppression list, a waterfall tries several data providers in order for a valid work email, AI columns write one or two merge fields from the company and the signal, and a webhook pushes the finished row into the sequence tool.
It replaced the spreadsheet-and-Zapier layer most teams used to build by hand, and it is the reason a two-person team can run five signal flows. The learning curve is real; the first table takes a week, the fifth takes an hour.
Tradeoff: Credit-based pricing punishes careless enrichment — filter for ICP before the waterfall, not after, or you pay to enrich people you then discard. And it is a workflow tool, not a sequencer; it needs a HeyReach or Instantly on the other end.
2. Trigify — LinkedIn engagement signals — the tool built for the job
Trigify watches LinkedIn for you: engagement on your own posts and thought leader ads, on competitors' posts, on influencers in your category, and on keyword topics. It returns the engagers as people, not just counts, and hands them to Clay by integration. It also catches job-change and funding announcements as posts ("excited to announce I've joined…") earlier than databases record them.
This is signal source one, three and four on the signal-based outbound page. Without it you are exporting engager lists by hand.
Tradeoff: It only sees what happens on LinkedIn. Website intent and CRM history live elsewhere. And engagement on a post is a weaker signal than a pricing-page visit — rank accordingly.
3. Phantombuster — a cheap one-month test of the idea, or one-off scrapes
Phantombuster does the same basic extraction Trigify does — who liked or commented on a post — as scheduled jobs you configure and maintain. It is broader (it scrapes many sites and many LinkedIn objects) and cheaper, and it is the right choice if you want to prove the concept for a month before committing.
The full comparison is in Trigify vs Phantombuster for signal-based outreach.
Tradeoff: It is a scraper, not a monitor. Continuous topic and competitor listening, de-duplication across sources, and the hand-off to Clay are things you build and babysit yourself. Rate limits and LinkedIn's terms are your problem to manage.
4. RB2B — person-level website visitor identification (US)
RB2B turns the highest-intent signal there is — a named person on your pricing or demo page — into a row you can act on within the hour. It is US-only for person-level identification, which is the trade-off for its precision, and it feeds Clay directly.
Pair it with a page filter: pricing, demo, comparison and integration pages are signals; the blog is not.
Tradeoff: US-only at the person level, and privacy expectations differ by market — for UK and EU traffic you are back to company-level tools. Treat it as a US-market add-on, not the core.
5. Warmly — company-level website intent with built-in orchestration
Warmly identifies visiting companies, enriches them, and can route them to reps or trigger outreach from inside the product, so teams without a Clay setup can get a signal flow running faster. It also layers third-party intent on top of first-party visits.
Dealfront (formerly Leadfeeder) and Lead Forensics sit in the same category: company-level identification with a CRM push. Pick on your market — Dealfront and Lead Forensics are stronger in the UK and Europe, Warmly and RB2B in the US.
Tradeoff: Company-level means you still have to find the person; Clay does that, so most teams end up with both. Bundled orchestration is convenient until you want to change the logic.
6. UserGems — job-change signals on people you already know
UserGems watches your CRM contacts and tells you when one of them moves to a new company — the single most reliable buying signal in B2B, because the person already knows the product. Champify does the same. Both push the new company and role into the CRM and to Slack.
Clay can monitor job changes on any list, not just people you know, which is the version most of the job-change and funding-round sequence is built on.
Tradeoff: Only as good as your CRM history — a young company with few past customers gets few alerts. Priced for teams with a sizeable contact base.
7. HeyReach — LinkedIn sequencing across multiple sender accounts
HeyReach is built for running LinkedIn sequences from several profiles at once — the founder, two salespeople and a marketer — with one inbox and one set of limits, which is why agencies and outbound teams standardised on it. It accepts contacts by API with custom fields, so Clay can enrol a signal-triggered person with the merge fields attached.
Aimfox is the closest alternative and the one we run alongside it; La Growth Machine, Expandi and Dripify cover the same ground with different multi-channel and safety trade-offs.
Tradeoff: LinkedIn automation lives in a grey area of the platform's terms; sensible daily limits and warmed accounts matter more than any feature. Email still needs a separate tool.
8. Instantly — cold and signal email at scale, with deliverability built in
Instantly made high-volume email outbound survivable by bundling mailbox warm-up, rotation and deliverability monitoring with the sequencer. For signal-based flows the feature that matters is the API: Clay pushes a contact with the signal fields, Instantly enrols them, and a reply webhook suppresses them everywhere else.
Smartlead is the equivalent choice with a similar model; lemlist adds LinkedIn steps into the same sequence; Apollo bundles a database with the sequencer for teams that want one tool.
Tradeoff: Volume tooling invites volume behaviour. The signal-based sequence is four touches over twelve days; the product will happily let you run eight over thirty, and your reply rate will tell you why not to.
9. Bombora — third-party intent data for prioritising an account list
Bombora, 6sense and G2 Buyer Intent tell you which companies are reading about your category across the web. That is useful for deciding which accounts to warm up with ads first, and for ranking a list — it is not a trigger to send a message, because you cannot reference it in the first line without sounding like surveillance.
In the ranked list of signals it is number ten: a prioritisation input, not an opener.
Tradeoff: Expensive relative to first-party signals, and the surge you see is often a competitor's SDR team researching. Use it to order the list, never to write the email.
10. Cargo — teams that want to own the workflow layer
Cargo competes with Clay on the orchestration layer with more emphasis on routing, territory logic and CRM write-back, which matters once several reps and a RevOps function are in the loop. n8n is the open-source route for teams that would rather host the workflow themselves.
Most teams start on Clay and stay; Cargo is the one to evaluate when the routing rules get complicated.
Tradeoff: Smaller ecosystem and fewer templates than Clay, so more building from scratch.
Three stacks by stage
| Stage | Detection | Orchestration | Sequencing | Who runs it |
|---|---|---|---|---|
| Test the idea (one month) | Phantombuster on your own posts and two competitors' | Clay starter, one table | Instantly or HeyReach, one sender each | One person, a few hours a week |
| Running system | Trigify + a website tool for your market (RB2B in the US; Dealfront or Lead Forensics in the UK/EU) | Clay, one table per signal type, CRM suppression synced | HeyReach or Aimfox (2–4 senders) + Instantly or Smartlead | A GTM engineer or an agency; an SDR on replies |
| Multi-rep, multi-territory | All of the above + UserGems or Champify on the CRM + intent data for list ordering | Clay or Cargo with routing rules | Same, more senders, per-rep inboxes | RevOps owns the logic; SDRs own replies |
How to choose: five questions
- "Where do my signals come from today?" If the answer is "we don't have any", the first purchase is not a tool on this list — it is the ads and content that create them. Signals are made, not bought.
- "Can Clay push into it, and can it push back?" Webhook in, reply webhook out. If either is missing, the tool sits outside the system and someone copies and pastes.
- "What happens when someone replies?" The correct answer is: suppressed from every sequence on every channel within minutes, and a human notified with the signal attached. Most tools do half of this.
- "Person-level or company-level?" Website tools split on this and on geography. Company-level plus Clay is fine; it is one more enrichment step.
- "How many senders, and are they warm?" On LinkedIn and email alike, the binding constraint is not the software, it is the number of accounts you can send from safely. Plan senders before features.
What Kiin runs, and why
Trigify for LinkedIn signals because it is the only monitor built for it. Clay in the middle because everything speaks to it. HeyReach and Aimfox for LinkedIn because our clients have several senders. Instantly and Smartlead for email because deliverability is bundled. Slack for the hand-off because that is where the SDR already is. The CRM — HubSpot, Attio or Pipedrive — for suppression and attribution, because a signal-based system that cannot see open opportunities will message your own pipeline.
The reason we run it alongside LinkedIn Ads rather than as a standalone service is on the GTM outbound page: the ads are the signal factory, and the data on the warm side — retargeting getting 71% more conversation-ad leads per send than cold, a retargeting pool booking 55% of calendar clicks — is the same warmth that makes a signal-triggered email get a reply.