Inflection.io

Inflection.io is a B2B marketing automation platform positioned as a modern, AI-native replacement for legacy tools like Marketo. It unifies target accounts, product users, customers, and leads with product-usage, sales, and behavioral signals so marketing teams can build audiences, draft campaigns, map customer journeys, score accounts, and report to the CMO — executing in minutes rather than weeks. The Inflection Developer API is a JSON-over-HTTPS REST API (OpenAPI 3.1, base https://api.inflection.io/v1) for reading and writing the people in a workspace: their profiles, product and marketing activity, static lists, emails, and per-contact personalized email versions, authenticated with scoped Personal Access Tokens or an OAuth 2.1 connected app. Alongside it Inflection runs a first-party remote MCP server at mcp.inflection.io — OAuth 2.1 with PKCE, its own trust and security page — that exposes the authoring surface the REST API does not: journeys, audiences, segments, tokens and analytics, driven by specialist agents. Surfaced as a version-one-ventures portfolio company and enriched from the provider's public developer, agent, and trust surfaces.

Inflection.io publishes 5 APIs on the APIs.io network, including Contact Activity API, Contacts API, Emails API, and 2 more. Tagged areas include Company, Software-as-a-Service, Marketing, Marketing Automation, and Email Marketing.

The Inflection.io catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Inflection.io’s developer surface includes documentation, API reference, getting-started guide, support, engineering blog, pricing, signup flow, and 35 more developer resources.

🌐 Visit website 📡 Source on GitHub

59.6/100 strong ▬ flat Agent 49/100 agent ready saas Full breakdown ↓
scored 2026-09-06 · rubric v0.19.0

1 APIs 1 MCP Servers

Company Software-as-a-Service Marketing Marketing Automation Email Marketing Customer Data B2B Contacts MCP Agents Artificial Intelligence Customer Journeys Webhook

Kin Score

Kin Score How this is scored →
scored 2026-09-06 · rubric v0.19.0

Composite quality — 59.6/100 · strong

Contract Quality 15.8 / 25

Developer Ergonomics 12.9 / 20

Access Clarity 13.7 / 20

Operational Transparency 7.5 / 13

Contract Governance 2.2 / 12

Discoverability 7.6 / 10

Agent readiness — 49/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/inflectionio: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 6

Individual APIs this provider publishes, each with its own machine-readable definition.

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Rate Limits 1

Documented rate limits and quota policies.

Scopes 1

OAuth scopes governing access to this provider's APIs.

Inflectionio Scopes

3 scopes · authorizationCode

3 scopes

SCOPES

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Login

Documentation 3

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

OpenAPI

OpenAPI

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

MCPServer

AgentSkill

WellKnown

LLMsTxt

AgenticAccess

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

DataModel

Lifecycle

Conformance

Webhooks

Components

Scroll for all 7

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

ToolCrosswalk

ToolCrosswalk

Packages

Packages

Access & Security 7

Authentication, authorization, and security posture

Authentication

OAuthScopes

Compliance

TrustCenter

Security

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Scroll for all 7

Operate 5

Status, limits, changes, and where to get help

HelpCenter

Support

ChangeLog

ChangeLog

RateLimits

Commercial 4

Pricing, plans, and the legal terms of use

Pricing

TermsOfService

PrivacyPolicy

Plans

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

Overlay

Overlay

AgentCard

AgentCard

Source (apis.yml)

aid: inflectionio
name: Inflection.io
description: 'Inflection.io is a B2B marketing automation platform positioned as a modern, AI-native replacement for legacy
  tools like Marketo. It unifies target accounts, product users, customers, and leads with product-usage, sales, and behavioral
  signals so marketing teams can build audiences, draft campaigns, map customer journeys, score accounts, and report to the
  CMO — executing in minutes rather than weeks. The Inflection Developer API is a JSON-over-HTTPS REST API (OpenAPI 3.1, base
  https://api.inflection.io/v1) for reading and writing the people in a workspace: their profiles, product and marketing activity,
  static lists, emails, and per-contact personalized email versions, authenticated with scoped Personal Access Tokens or an
  OAuth 2.1 connected app. Alongside it Inflection runs a first-party remote MCP server at mcp.inflection.io — OAuth 2.1 with
  PKCE, its own trust and security page — that exposes the authoring surface the REST API does not: journeys, audiences, segments,
  tokens and analytics, driven by specialist agents. Surfaced as a version-one-ventures portfolio company and enriched from
  the provider''s public developer, agent, and trust surfaces.'
url: https://raw.githubusercontent.com/api-evangelist/inflectionio/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: usage
  onboarding: sales
  trial: false
  try_now: false
  public: false
  label: Annual contract, MMC-metered, published price ladder
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-08-13'
  method: searched
image: https://www.inflection.io/img/asset/YXNzZXRzL29nLWltYWdlLmpwZw/og-image.jpg
x-type: company
x-source: vc-portfolio
x-backed-by:
- version-one-ventures
x-tier: enriched
x-tier-reason: public-developer-api
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-08-13'
tags:
- Company
- Software-as-a-Service
- Marketing
- Marketing Automation
- Email Marketing
- Customer Data
- B2B
- Contacts
- MCP
- Agents
- Artificial Intelligence
- Customer Journeys
- Webhook
tags_raw:
- Company
- Saas
- Marketing
- Marketing Automation
- Email Marketing
- Customer Data
- B2B
- Contacts
- API
- MCP
- Agents
- Artificial Intelligence
- Customer Journeys
- Webhooks
apis:
- aid: inflectionio:inflectionio-contact-activity-api
  name: Inflection.io Contact Activity API
  description: The Contact Activity API from Inflection.io — 4 operation(s) for contact activity.
  humanURL: https://docs.inflection.io/api-reference/introduction
  baseURL: https://api.inflection.io/v1
  tags:
  - Contact Activity
  properties:
  - type: OpenAPI
    url: openapi/inflectionio-contact-activity-api-openapi.yml
  - type: Documentation
    url: https://docs.inflection.io/api-reference/introduction
  - type: APIReference
    url: https://docs.inflection.io/api-reference/contact-activity/get-product-activity
- aid: inflectionio:inflectionio-contacts-api
  name: Inflection.io Contacts API
  description: The Contacts API from Inflection.io — 6 operation(s) for contacts.
  humanURL: https://docs.inflection.io/api-reference/introduction
  baseURL: https://api.inflection.io/v1
  tags:
  - Contacts
  properties:
  - type: OpenAPI
    url: openapi/inflectionio-contacts-api-openapi.yml
  - type: Documentation
    url: https://docs.inflection.io/api-reference/introduction
  - type: APIReference
    url: https://docs.inflection.io/api-reference/contacts/get-contact-by-id
- aid: inflectionio:inflectionio-emails-api
  name: Inflection.io Emails API
  description: The Emails API from Inflection.io — 2 operation(s) for creating and reading HTML emails.
  humanURL: https://docs.inflection.io/api-reference/introduction
  baseURL: https://api.inflection.io/v1
  tags:
  - Emails
  properties:
  - type: OpenAPI
    url: openapi/inflectionio-emails-api-openapi.yml
  - type: Documentation
    url: https://docs.inflection.io/api-reference/introduction
  - type: APIReference
    url: https://docs.inflection.io/api-reference/emails/create-an-email
- aid: inflectionio:inflectionio-email-versions-api
  name: Inflection.io Email Versions API
  description: The Email Versions API from Inflection.io — 1 operation for pushing a per-contact personalized version of a
    Personalized Email Asset.
  humanURL: https://docs.inflection.io/api-reference/introduction
  baseURL: https://api.inflection.io/v1
  tags:
  - Email Versions
  properties:
  - type: OpenAPI
    url: openapi/inflectionio-email-versions-api-openapi.yml
  - type: Documentation
    url: https://docs.inflection.io/agents/personalized-email
  - type: APIReference
    url: https://docs.inflection.io/api-reference/email-versions/set-a-personalized-email-version
- aid: inflectionio:inflectionio-lists-and-members-api
  name: Inflection.io Lists and Members API
  description: The Lists and Members API from Inflection.io — 7 operation(s) for lists and members.
  humanURL: https://docs.inflection.io/api-reference/introduction
  baseURL: https://api.inflection.io/v1
  tags:
  - Lists and Members
  properties:
  - type: OpenAPI
    url: openapi/inflectionio-lists-and-members-api-openapi.yml
  - type: Documentation
    url: https://docs.inflection.io/api-reference/introduction
  - type: APIReference
    url: https://docs.inflection.io/api-reference/lists-and-members/create-a-list
- aid: inflectionio:inflectionio-mcp
  name: Inflection MCP
  description: Inflection's first-party remote MCP server — the agent-facing authoring surface for journeys, audiences, segments,
    emails, tokens and analytics, gated by OAuth 2.1 with PKCE.
  humanURL: https://docs.inflection.io/agents/inflection-mcp
  baseURL: https://mcp.inflection.io/
  tags:
  - MCP
  - Agents
  properties:
  - type: MCPServer
    url: mcp/inflectionio-mcp.yml
  - type: ToolCrosswalk
    url: mcp/inflectionio-tool-crosswalk.yml
  - type: Documentation
    url: https://docs.inflection.io/agents/inflection-mcp
  - type: Authentication
    url: https://docs.inflection.io/agents/connected-apps-oauth
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://www.inflection.io
- type: DeveloperPortal
  url: https://docs.inflection.io/api-reference/introduction
- type: Documentation
  url: https://docs.inflection.io/api-reference/introduction
- type: APIReference
  url: https://docs.inflection.io/api-reference/introduction
- type: GettingStarted
  url: https://docs.inflection.io/api-reference/quickstart
- type: HelpCenter
  url: https://docs.inflection.io
- type: Support
  url: https://docs.inflection.io
- type: Blog
  url: https://www.inflection.io/blog
- type: Pricing
  url: https://www.inflection.io/pricing
- type: SignUp
  url: https://app.inflection.io/login/start
- type: Login
  url: https://app.inflection.io/login/start
- type: TermsOfService
  url: https://www.inflection.io/legal/terms
- type: PrivacyPolicy
  url: https://www.inflection.io/legal/privacy-policy
- type: GitHubOrganization
  url: https://github.com/inflectionio
- type: ChangeLog
  url: https://docs.inflection.io/whats-new/july-2026
- type: ChangeLog
  url: changelog/inflectionio-changelog.yml
- type: OpenAPI
  url: openapi/_original/inflectionio-openapi-original.yml
- type: Overlay
  url: overlays/inflectionio-openapi-overlay.yaml
- type: Authentication
  url: authentication/inflectionio-authentication.yml
- type: OAuthScopes
  url: scopes/inflectionio-scopes.yml
- type: Conventions
  url: conventions/inflectionio-conventions.yml
- type: ErrorCatalog
  url: errors/inflectionio-problem-types.yml
- type: DataModel
  url: data-model/inflectionio-data-model.yml
- type: Lifecycle
  url: lifecycle/inflectionio-lifecycle.yml
- type: Conformance
  url: conformance/inflectionio-conformance.yml
- type: Compliance
  url: https://docs.inflection.io/agents/mcp-trust-security
- type: TrustCenter
  url: security/inflectionio-trust-center.yml
- type: Security
  url: https://docs.inflection.io/agents/mcp-trust-security
- type: VulnerabilityDisclosure
  url: security/inflectionio-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/inflectionio-domain-security.yml
- type: MCPServer
  url: mcp/inflectionio-mcp.yml
- type: ToolCrosswalk
  url: mcp/inflectionio-tool-crosswalk.yml
- type: AgentCard
  url: a2a/inflectionio-a2a.yml
- type: AgentSkill
  url: skills/_index.yml
- type: WellKnown
  url: well-known/inflectionio-well-known.yml
- type: LLMsTxt
  url: llms/inflectionio-llms.txt
- type: AgenticAccess
  url: agentic-access/inflectionio-agentic-access.yml
- type: RateLimits
  url: rate-limits/inflectionio-rate-limits.yml
- type: Plans
  url: plans/inflectionio-plans-pricing.yml
- type: Webhooks
  url: asyncapi/inflectionio-webhooks.yml
- type: Packages
  url: packages/inflectionio-packages.yml
- type: Components
  url: components/inflectionio-components.yml
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 18
  pass: local-v1

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