Apollo API Documentation
Apollo.io provides a comprehensive REST API for sales intelligence with over 210 million contacts and 35 million companies. The Apollo API enables data enrichment, people and organization search, CRM management, sequences, deals, analytics, and integrations. Authentication is via API keys or OAuth 2.0 for partner integrations. This repository profiles Apollo.io's API documentation as an example of API documentation best practices.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles Apollo API Documentation the way a machine reads it — 35 machine-readable artifacts across 14 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 — Apollo API Documentation scores 41.2/100 (thin), with a separate agent-readiness read of 48/100 (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.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile Apollo API Documentation
Each block below is one kind of artifact we hold for Apollo API Documentation. 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 14
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.
Apollo API Documentation Accounts API
The Accounts API from Apollo API Documentation — 3 operation(s) for accounts.
Apollo API Documentation Contacts API
The Contacts API from Apollo API Documentation — 3 operation(s) for contacts.
Apollo API Documentation Email Accounts API
The Email Accounts API from Apollo API Documentation — 1 operation(s) for email accounts.
Apollo API Documentation Emailer Campaigns API
The Emailer Campaigns API from Apollo API Documentation — 3 operation(s) for emailer campaigns.
Apollo API Documentation Mixed Companies API
The Mixed Companies API from Apollo API Documentation — 1 operation(s) for mixed companies.
Apollo API Documentation Mixed People API
The Mixed People API from Apollo API Documentation — 1 operation(s) for mixed people.
Apollo API Documentation Opportunities API
The Opportunities API from Apollo API Documentation — 3 operation(s) for opportunities.
Apollo API Documentation Organizations API
The Organizations API from Apollo API Documentation — 2 operation(s) for organizations.
Apollo API Documentation People API
The People API from Apollo API Documentation — 2 operation(s) for people.
Apollo API Documentation Phone Calls API
The Phone Calls API from Apollo API Documentation — 3 operation(s) for phone calls.
Apollo API Documentation Sync Report API
The Sync Report API from Apollo API Documentation — 1 operation(s) for sync report.
Apollo API Documentation Tasks API
The Tasks API from Apollo API Documentation — 3 operation(s) for tasks.
Apollo API Documentation Usage Stats API
The Usage Stats API from Apollo API Documentation — 1 operation(s) for usage stats.
Apollo API Documentation Users API
The Users API from Apollo API Documentation — 1 operation(s) for users.
Scroll within the panel for all 14 ·
Open Collections 1
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).
Apollo.io API
OPEN COLLECTIONPricing 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 six things the Kin Score reads for commercial clarity.
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.
Apollo Api Documentation Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Features 8
The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.
Notable capabilities this provider offers.
People Enrichment
Enrich contact records with data from Apollo's 210M+ contact database.
Organization Enrichment
Enrich company records with data from Apollo's 35M+ company database.
People Search
Search Apollo's contact database to find and identify sales prospects.
Organization Search
Search Apollo's company database for target accounts and job postings.
CRM Integration
Manage accounts, contacts, deals, and sequences via the REST API.
OAuth 2.0 Partner Integration
Partners use OAuth 2.0 to build integrations accessing Apollo data on behalf of customers.
Interactive Try It
Interactive API testing capability built directly into the documentation.
Analytics Reporting
Query analytics reports for performance metrics via the API.
Scroll within the panel for all 8 ·
Security Posture 2
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.
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.
Use Cases 4
What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.
What developers build with this provider.
Sales Intelligence
Access Apollo's contact and company database for prospecting and outreach.
Data Enrichment Pipelines
Enrich CRM records with contact and organization data at scale.
Partner Integrations
Build third-party integrations using OAuth 2.0 to access Apollo data for mutual customers.
Workflow Automation
Automate sales workflows including sequences, tasks, and deal management.
Integrations 2
Pre-built integrations with other platforms tell you where this provider already fits in a stack.
Pre-built integrations with other platforms and tools.
OAuth 2.0
Partner integration protocol for accessing Apollo data on behalf of customers.
API Key Authentication
Direct API key access for customers building internal integrations.
Resources
Every other property we hold for Apollo API Documentation — 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 1
Portal, sign-up, and the first successful call
Documentation 2
Reference material describing how the API behaves
Agent Surfaces 2
MCP servers, agent skills, and machine-readable catalogs
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 3
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Company 1
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/apollo-api-documentation · machine-readable index on apis.io