Need help with your APIs? I offer API discovery, governance & evangelism services. Explore services →
API Evangelist API Evangelist
Discovery
Learnings
Guidance
Toolbox
Alignment
API Evangelist LLC
Kit website screenshot

Kit

Kit (formerly ConvertKit) is a creator email marketing platform with a REST API for managing subscribers, tags, sequences, forms, broadcasts, and automation rules. The API supports both API key and OAuth 2.0 authentication, with v4 as the current version featuring cursor-based pagination, bulk operations, and async processing.

agent ready

Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.

Kin Score

API Evangelist profiles Kit the way a machine reads it — 197 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 — Kit scores 52.6/100 (developing), 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 Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 52.6/100 · developing
Contract Quality 12.4 / 25
Developer Ergonomics 4.3 / 20
Commercial Clarity 11.6 / 20
Operational Transparency 5.5 / 13
Governance 8.8 / 12
Discoverability 10.0 / 10
Agent readiness — 48/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3

How we profile Kit

Each block below is one kind of artifact we hold for Kit. 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.

Kit Accounts API

The Accounts API from Kit — 5 operation(s) for accounts.

Kit Broadcasts API

The Broadcasts API from Kit — 5 operation(s) for broadcasts.

Kit Custom Fields API

The Custom Fields API from Kit — 4 operation(s) for custom fields.

Kit Email Templates API

The Email Templates API from Kit — 1 operation(s) for email templates.

Kit Forms API

The Forms API from Kit — 4 operation(s) for forms.

Kit Posts API

The Posts API from Kit — 2 operation(s) for posts.

Kit Purchases API

The Purchases API from Kit — 2 operation(s) for purchases.

Kit Segments API

The Segments API from Kit — 1 operation(s) for segments.

Kit Sequence Emails API

The Sequence Emails API from Kit — 2 operation(s) for sequence emails.

Kit Sequences API

The Sequences API from Kit — 4 operation(s) for sequences.

Kit Snippets API

The Snippets API from Kit — 2 operation(s) for snippets.

Kit Subscribers API

The Subscribers API from Kit — 7 operation(s) for subscribers.

Kit Tags API

The Tags API from Kit — 6 operation(s) for tags.

Kit Webhooks API

The Webhooks API from Kit — 2 operation(s) for webhooks.

Scroll within the panel for all 14 ·

GraphQL 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.

Kit (ConvertKit) GraphQL API

Kit (formerly ConvertKit) is a creator email marketing platform. This conceptual GraphQL schema wraps the Kit REST API v4, providing queries for subscribers, tags, sequences, fo...

GRAPHQL

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 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.

Convertkit Rate Limits

2 limits

RATE LIMITS

FinOps 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.

Spectral Rules 1

Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.

Kit API Rules

5 rules · 4 warnings

SPECTRAL

JSON Schema 100

Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.

Standalone JSON Schema definitions for this provider's data models.

BroadcastAnyCondition

2 properties

JSON SCHEMA

FilterCondition

9 properties

JSON SCHEMA

FormsAnyCondition

2 properties

JSON SCHEMA

IdsAnyCondition

2 properties

JSON SCHEMA

SubscriberFilterRequest

2 properties

JSON SCHEMA

UrlAnyCondition

4 properties

JSON SCHEMA

Add subscriber to form Request

1 properties

JSON SCHEMA

Add subscriber to form Response

1 properties

JSON SCHEMA

Add subscriber to sequence Request

0 properties

JSON SCHEMA

Add subscriber to sequence Response

1 properties

JSON SCHEMA

Bulk add subscribers to forms Request

2 properties

JSON SCHEMA

Bulk create custom fields Request

2 properties

JSON SCHEMA

Bulk create custom fields Response

2 properties

JSON SCHEMA

Bulk create subscribers Request

2 properties

JSON SCHEMA

Bulk create subscribers Response

2 properties

JSON SCHEMA

Bulk create tags Request

2 properties

JSON SCHEMA

Bulk create tags Response

2 properties

JSON SCHEMA

Bulk tag subscribers Request

2 properties

JSON SCHEMA

Bulk tag subscribers Response

2 properties

JSON SCHEMA

Create a broadcast Request

12 properties

JSON SCHEMA

Create a broadcast Response

1 properties

JSON SCHEMA

Create a custom field Request

1 properties

JSON SCHEMA

Create a custom field Response

1 properties

JSON SCHEMA

Create a purchase Request

1 properties

JSON SCHEMA

Create a purchase Response

1 properties

JSON SCHEMA

Create a sequence email Request

9 properties

JSON SCHEMA

Create a sequence email Response

1 properties

JSON SCHEMA

Create a sequence Request

10 properties

JSON SCHEMA

Create a sequence Response

1 properties

JSON SCHEMA

Create a snippet Request

0 properties

JSON SCHEMA

Create a snippet Response

1 properties

JSON SCHEMA

Create a subscriber Request

4 properties

JSON SCHEMA

Create a subscriber Response

2 properties

JSON SCHEMA

Create a tag Request

1 properties

JSON SCHEMA

Create a tag Response

1 properties

JSON SCHEMA

Create a webhook Request

2 properties

JSON SCHEMA

Create a webhook Response

1 properties

JSON SCHEMA

Get a broadcast Response

1 properties

JSON SCHEMA

Get a post Response

1 properties

JSON SCHEMA

Get a purchase Response

1 properties

JSON SCHEMA

Get a sequence email Response

1 properties

JSON SCHEMA

Get a sequence Response

1 properties

JSON SCHEMA

Get a snippet Response

1 properties

JSON SCHEMA

Get a subscriber Response

1 properties

JSON SCHEMA

Get Creator Profile Response

1 properties

JSON SCHEMA

Get current account Response

2 properties

JSON SCHEMA

Get email stats Response

1 properties

JSON SCHEMA

Get growth stats Response

1 properties

JSON SCHEMA

Get stats for a broadcast Response

1 properties

JSON SCHEMA

List broadcasts Response

2 properties

JSON SCHEMA

List colors Response

1 properties

JSON SCHEMA

List custom fields Response

2 properties

JSON SCHEMA

List email templates Response

2 properties

JSON SCHEMA

List forms Response

2 properties

JSON SCHEMA

List posts Response

2 properties

JSON SCHEMA

List purchases Response

2 properties

JSON SCHEMA

List segments Response

2 properties

JSON SCHEMA

List sequence emails Response

2 properties

JSON SCHEMA

List sequences Response

2 properties

JSON SCHEMA

List snippets Response

2 properties

JSON SCHEMA

List stats for a subscriber Response

1 properties

JSON SCHEMA

List subscribers for a form Response

2 properties

JSON SCHEMA

List subscribers for a tag Response

2 properties

JSON SCHEMA

List subscribers Response

2 properties

JSON SCHEMA

List tags for a subscriber Response

2 properties

JSON SCHEMA

List tags Response

2 properties

JSON SCHEMA

List webhooks Response

2 properties

JSON SCHEMA

Tag a subscriber Request

0 properties

JSON SCHEMA

Tag a subscriber Response

1 properties

JSON SCHEMA

Unsubscribe subscriber Request

0 properties

JSON SCHEMA

Update a broadcast Request

12 properties

JSON SCHEMA

Update a broadcast Response

1 properties

JSON SCHEMA

Update a custom field Request

1 properties

JSON SCHEMA

Update a custom field Response

1 properties

JSON SCHEMA

Update a sequence email Request

9 properties

JSON SCHEMA

Update a sequence email Response

1 properties

JSON SCHEMA

Update a sequence Request

10 properties

JSON SCHEMA

Update a sequence Response

1 properties

JSON SCHEMA

Update a snippet Request

0 properties

JSON SCHEMA

Update a snippet Response

1 properties

JSON SCHEMA

Update a subscriber Request

3 properties

JSON SCHEMA

Update a subscriber Response

2 properties

JSON SCHEMA

Update colors Request

1 properties

JSON SCHEMA

Update colors Response

1 properties

JSON SCHEMA

Update tag name Request

1 properties

JSON SCHEMA

Update tag name Response

1 properties

JSON SCHEMA

Scroll within the panel for all 100 ·

Examples 72

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.

Add Subscriber To Form

6 fields

EXAMPLE

Bulk Create Custom Fields

6 fields

EXAMPLE

Bulk Create Subscribers

6 fields

EXAMPLE

Bulk Create Tags

6 fields

EXAMPLE

Bulk Tag Subscribers

6 fields

EXAMPLE

Create A Broadcast

6 fields

EXAMPLE

Create A Custom Field

6 fields

EXAMPLE

Create A Purchase

6 fields

EXAMPLE

Create A Sequence Email

6 fields

EXAMPLE

Create A Sequence

6 fields

EXAMPLE

Create A Snippet

5 fields

EXAMPLE

Create A Subscriber

6 fields

EXAMPLE

Create A Tag

6 fields

EXAMPLE

Create A Webhook

6 fields

EXAMPLE

Delete A Broadcast

4 fields

EXAMPLE

Delete A Sequence Email

4 fields

EXAMPLE

Delete A Sequence

4 fields

EXAMPLE

Delete A Webhook

4 fields

EXAMPLE

Delete Custom Field

4 fields

EXAMPLE

Get A Broadcast

5 fields

EXAMPLE

Get A Post

5 fields

EXAMPLE

Get A Purchase

5 fields

EXAMPLE

Get A Sequence Email

5 fields

EXAMPLE

Get A Sequence

5 fields

EXAMPLE

Get A Snippet

5 fields

EXAMPLE

Get A Subscriber

5 fields

EXAMPLE

Get Creator Profile

5 fields

EXAMPLE

Get Current Account

5 fields

EXAMPLE

Get Email Stats

5 fields

EXAMPLE

Get Growth Stats

5 fields

EXAMPLE

Get Stats For A Broadcast

5 fields

EXAMPLE

List Broadcasts

5 fields

EXAMPLE

List Colors

5 fields

EXAMPLE

List Custom Fields

5 fields

EXAMPLE

List Email Templates

5 fields

EXAMPLE

List Forms

5 fields

EXAMPLE

List Posts

5 fields

EXAMPLE

List Purchases

5 fields

EXAMPLE

List Segments

5 fields

EXAMPLE

List Sequence Emails

5 fields

EXAMPLE

List Sequences

5 fields

EXAMPLE

List Snippets

5 fields

EXAMPLE

List Subscribers

5 fields

EXAMPLE

List Tags

5 fields

EXAMPLE

List Webhooks

5 fields

EXAMPLE

Tag A Subscriber

5 fields

EXAMPLE

Unsubscribe Subscriber

4 fields

EXAMPLE

Update A Broadcast

6 fields

EXAMPLE

Update A Custom Field

6 fields

EXAMPLE

Update A Sequence Email

6 fields

EXAMPLE

Update A Sequence

6 fields

EXAMPLE

Update A Snippet

5 fields

EXAMPLE

Update A Subscriber

6 fields

EXAMPLE

Update Colors

6 fields

EXAMPLE

Update Tag Name

6 fields

EXAMPLE

Scroll within the panel for all 72 ·

Security 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.

Convertkit Authentication

apiKey/oauth2 · 2 schemes

SECURITY

Convertkit Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Convertkit Trust Center

SOC 2, ISO 27001, ISO 27018, GDPR

SECURITY

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.

Convertkit Scopes

2 scopes · authorizationCode

2 scopes

SCOPES

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.

Convertkit Agentic Access

72 operations · 39 acting

72 operations · 39 acting

AGENTIC

Resources

Every other property we hold for Kit — 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.

Documentation 1

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Build 1

SDKs, sample code, and the tooling you integrate with

Operate 2

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 3

The organization behind the API

Other 1

Properties that don't map to a standard resource type

← All providers · Data indexed from github.com/api-evangelist/convertkit · machine-readable index on apis.io