lemlist
lemlist is a sales engagement and cold outreach platform from lempire that helps sales teams build prospect lists, personalize multichannel campaigns across email, LinkedIn, phone, SMS and WhatsApp, and automate follow-ups to book more meetings. It includes a 650M+ record B2B lead database, credit-metered email and phone enrichment, Signal Agents that watch for buying triggers, a unified reply inbox, and lemwarm deliverability warm-up. The developer surface is unusually agent-forward for its category - a 143-operation REST API documented with a published OpenAPI, a hosted remote MCP server at app.lemlist.com/mcp with OAuth 2.1 and dynamic client registration, an official OpenAPI-generated CLI on npm, an llms.txt index, a published Agent Skill, and a 76-event webhook catalog.
Reference-quality API operations across every facet — a rich contract, published governance, transparent operations, and machine-readable commercial terms.
API Evangelist profiles lemlist the way a machine reads it — 39 machine-readable artifacts across 3 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — lemlist scores 70.1/100 (exemplar), with a separate agent-readiness read of 61/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-08 · rubric v0.20.0
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How we profile lemlist
Each block below is one kind of artifact we hold for lemlist. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 22
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
lemlist MCP Server
lemlist's hosted remote Model Context Protocol server. An MCP client POSTs to https://app.lemlist.com/mcp and authenticates with OAuth 2.1 (authorization code + PKCE, dynamic cl...
lemlist Campaigns API
Campaign CRUD and lifecycle - create, update, duplicate, start, pause, validation statutes, stats, reports and asynchronous exports.
lemlist Sequences API
Campaign sequences, their steps, and A/B test variants on email steps.
lemlist Leads API
Leads inside campaigns - create with optional enrichment, update, pause, resume, mark interested, custom variables, CRM import and unsubscribe.
lemlist People Database API
Search the lemlist B2B people and company database, list its filters, and manage saved personas.
lemlist Enrich API
Asynchronous enrichment - find and verify emails, phone numbers and LinkedIn data, single or in bulk, then poll for the result. Credit-metered.
lemlist Inbox API
The unified reply inbox - conversations, messages, drafts, labels and sending on email, LinkedIn and WhatsApp.
lemlist Contacts API
CRM-side contacts, contact lists, list membership and exports.
lemlist Companies API
CRM-side companies and company notes.
lemlist Signal Agents API
Signal Agents (watch lists) - create and configure watches, list the available signal types and filters, read detected signals, and push external signals.
lemlist Webhooks API
Webhook subscription management - list, create with an optional shared secret, and delete. 76 event types are documented.
lemlist Unsubscribes API
Suppression management - unsubscribe and re-subscribe contacts and variables, list and export the suppression set, and the legacy email/domain surface.
lemlist Schedules API
Sending schedules - CRUD and association with campaigns.
lemlist Tasks API
Manual tasks - list, create, update and ignore.
lemlist Activities API
The activity history feed, and deletion of call recordings and transcripts.
lemlist Team API
Team-level endpoints - team information, senders, remaining credits and CRM users.
lemlist Users API
User endpoints - user detail and the connected channels available to the authenticated user.
lemlist Email Accounts API
Connect, test and disconnect custom SMTP/IMAP sending accounts.
lemlist lemwarm API
lemwarm mailbox warm-up - start, pause, and read or update warm-up settings per mailbox.
lemlist Deliverability Alerts API
Threshold alerts on deliverability metrics - create, read, update and delete.
lemlist Fields API
The custom field definitions available on leads, contacts and companies.
lemlist Stats API
The Stats API from lemlist — 2 operation(s) for stats.
Scroll within the panel for all 22 ·
Open Collections 5
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
API Collection
OPEN COLLECTIONlemlist Campaigns API
OPEN COLLECTIONlemlist Campaigns Team API
OPEN COLLECTIONlemlist Campaigns Users API
OPEN COLLECTIONlemlist API
OPEN COLLECTIONMCP Servers 1
Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.
Model Context Protocol servers that expose these APIs to AI agents.
lemlist MCP Server
MCP SERVERGraphQL 1
Where a provider ships GraphQL, the schema is the contract. We profile it alongside the REST surface so the whole interface is legible in one place.
GraphQL schemas published by this provider.
Pricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the things the Kin Score reads for access clarity — renamed from commercial clarity in rubric 0.12, because a free statutory interface has access terms and no commercial ones.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Lemlist Rate Limits
RATE LIMITSEvent Specifications 1
Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Lemlist Webhooks
ASYNCAPIExamples 1
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Lemlist Examples
EXAMPLESecurity Posture 4
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Scopes 1
OAuth scopes are the vocabulary of least-privilege access. Profiling them shows exactly what an integration — or an agent acting on a user's behalf — is allowed to do.
OAuth scopes governing access to this provider's APIs.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for lemlist — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 4
Portal, sign-up, and the first successful call
Documentation 2
Reference material describing how the API behaves
Agent Surfaces 6
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 6
Pagination, idempotency, versioning, errors, and events
Build 5
SDKs, sample code, and the tooling you integrate with
Access & Security 7
Authentication, authorization, and security posture
Scroll within the panel for all 7 ·
Operate 4
Status, limits, changes, and where to get help
Commercial 4
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 2
Properties that don't map to a standard resource type
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This is an independent, third-party profile of lemlist, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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