Lookalike Prospect
Expand an ICP from a reference set of known-good companies or contacts. Requires a minimum of 5 references — the lookalike model degrades significantly below this threshold.
Step 1 — Validate Input Count
Count the number of reference companies or contacts provided.
If fewer than 5 are provided, stop and explain before doing anything else:
"Lusha's lookalike model needs at least 5 reference [companies/contacts] to return quality results — fewer than that produces unreliable matches. You've provided [N]. Can you add [5−N] more?"
Do not proceed until the user has provided at least 5 references.
If 5 or more are provided, confirm the reference set with the user:
"Running lookalike search using these [N] [companies/contacts] as the reference set: [list]. Shall I proceed?"
Step 2 — Determine Mode
Based on the user's input, determine whether this is a company lookalike or contact lookalike search:
- References are companies (domains, LinkedIn company URLs, or names) → company mode
- References are people (emails, LinkedIn profile URLs, or name + company) → contact mode
- Mixed input → ask the user to clarify
A bare job title is not a valid seed — a lookalike needs concrete reference companies or people. If the user only has a persona/title in mind, route them to prospect (ICP search) or signal-prospect instead.
Step 3 — Assemble the Seed Set
The lookalike tools accept raw identifiers directly as seeds — no enrichment or Lusha-ID resolution is needed in the common case. Pass the references straight through. The seed count (5–100) is the total identifiers across the seed arrays.
Company mode — lookalike_companies.seeds accepts:
domains(e.g.lusha.com)linkedinUrls(company page URLs)
If the user gave company names rather than domains, resolve each name to a domain first with companies_search (enrich: false — you only need the domain, not reveal data), since the seed schema does not accept bare names. If a name can't be resolved, flag it and proceed only if ≥5 seeds remain.
Contact mode — lookalike_contacts.seeds accepts any mix of:
emailslinkedinUrls(profile URLs)contacts—{ firstName, lastName, companyDomain | companyName }contactIds— Lusha contact IDs, if you already have them
Pass whatever form the user provided directly. No lookup step is needed.
Step 4 — Run Lookalike Search
Company mode: Use lookalike_companies with the seed set. limit up to 100 (default 25).
Contact mode: Use lookalike_contacts with the seed set. limit up to 50 (default 25).
Pass any known customers/won accounts in exclude (same identifier shape as seeds) to keep them out of the results. Results paginate via dedupeSessionId: omit it on the first call, then pass the returned token back on follow-up calls for the same seeds to fetch more non-duplicate matches (sessions expire after 30 days).
Step 5 — Find Decision Makers (Company Mode Only)
For the lookalike companies, use prospecting_contact_search scoped to them via companyDomains or companyNames, plus the target role. If the user hasn't specified one, ask: "What title or seniority are you targeting at these companies?"
Pass a specific title directly as jobTitles (free-form); for broader targeting, resolve seniority / departments via prospecting_contact_filters first.
Step 6 — Enrich and Reveal Phones
Search results are previews carrying a canReveal[] list per contact. Use prospecting_contact_enrich with the contact ids and reveal set from canReveal[].field to reveal direct and mobile numbers — up to 50 contacts per call. Sum the canReveal[].credits and state the total before enriching large batches.
Step 7 — Present Results
Reference Set Used
List the [N] references that were used. Flag any that could not be resolved.
Lookalike Results
Company mode:
Contact mode:
- Phone columns always appear before email — never reversed
- Mark missing phones with
—
Summary
- Lookalike [companies/contacts] found: X
- Decision makers enriched: Y
- Verified phones revealed: Z
Step 8 — Offer Next Actions
- Narrow results — apply additional filters (industry, geography, company size) to the lookalike list
- Cross with signals — run
signal-prospecton this lookalike list to surface which ones are showing buying signals right now - Expand the reference set — add more references to improve match quality
- Export — format as CSV

