SharpSpring

SharpSpring — now sold as Constant Contact Lead Gen & CRM after Constant Contact acquired the company in 2021 — is a marketing automation and CRM platform for small businesses and digital marketing agencies, covering email marketing, landing pages, forms, visual automation workflows, social management, campaign tracking, lead scoring and a built-in sales CRM. Its developer surface is the SharpSpring Open API, a JSON-RPC-style HTTPS POST endpoint at api.sharpspring.com/pubapi/ that exposes roughly 120 published methods over leads, accounts, opportunities, campaigns, deal stages, emails, email jobs, lists and list members, fields, folders, notes, products and tasks. Authentication is a static account ID plus secret key generated in the application; there is no OAuth, no scopes and no OpenAPI description. Event delivery is handled by workflow and form Postback URLs rather than a webhook subscription API.

SharpSpring publishes 1 API on the APIs.io network. Tagged areas include Company, Marketing, Marketing Automation, CRM, and Email Marketing.

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

SharpSpring’s developer surface includes documentation, API reference, getting-started guide, support, engineering blog, pricing, signup flow, and 24 more developer resources.

🌐 Visit website 📡 Source on GitHub

47.0/100 developing ▬ flat Agent 25/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

1 APIs

Company Marketing Marketing Automation CRM Email Marketing Sales Leads Campaigns Automation Software-as-a-Service

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 47.0/100 · developing

Contract Quality 10.4 / 25

Developer Ergonomics 11.4 / 20

Access Clarity 8.9 / 20

Operational Transparency 8.9 / 13

Contract Governance 0.5 / 12

Discoverability 6.9 / 10

Agent readiness — 25/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 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 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 0 / 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 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

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/sharpspring: 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 1

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

SharpSpring Open API

The SharpSpring (Constant Contact Lead Gen & CRM) Open API — a single HTTPS POST endpoint that accepts a JSON envelope of method, params and id, very similar to JSON-RPC. Versio...

Pricing Plans 1

Published pricing tiers and plan structures.

Sharpspring Plans Pricing

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Sharpspring Rate Limits

5 limits

RATE LIMITS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Sharpspring Postbacks Webhooks

ASYNCAPI

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Sharpspring Authentication

apiKey · 2 schemes

SECURITY

Sharpspring Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Sharpspring Vulnerability Disclosure

Hackerone · security.txt · contact published

SECURITY

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Login

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

WellKnown

WellKnown

LLMsTxt

LLMsTxt

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

Lifecycle

Conformance

DataModel

Webhooks

Build 2

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

Access & Security 5

Authentication, authorization, and security posture

DomainSecurity

Security

SecurityTxt

Authentication

VulnerabilityDisclosure

VulnerabilityDisclosure

Operate 4

Status, limits, changes, and where to get help

Support

HelpCenter

StatusPage

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

Source (apis.yml)

aid: sharpspring
name: SharpSpring
description: SharpSpring — now sold as Constant Contact Lead Gen & CRM after Constant Contact acquired the company in 2021
  — is a marketing automation and CRM platform for small businesses and digital marketing agencies, covering email marketing,
  landing pages, forms, visual automation workflows, social management, campaign tracking, lead scoring and a built-in sales
  CRM. Its developer surface is the SharpSpring Open API, a JSON-RPC-style HTTPS POST endpoint at api.sharpspring.com/pubapi/
  that exposes roughly 120 published methods over leads, accounts, opportunities, campaigns, deal stages, emails, email jobs,
  lists and list members, fields, folders, notes, products and tasks. Authentication is a static account ID plus secret key
  generated in the application; there is no OAuth, no scopes and no OpenAPI description. Event delivery is handled by workflow
  and form Postback URLs rather than a webhook subscription API.
url: https://raw.githubusercontent.com/api-evangelist/sharpspring/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - rate-limits
  - security
  generated: '2026-09-03'
  method: derived
image: https://sharpspring.com/wp-content/uploads/2021/10/SharpSpring-From-CTCT-Logo-RGB-Color-1200.png
x-type: company
x-source: harvest:marketing-integration-graph
x-tier: stub
x-tier-reason: harvest
specificationVersion: '0.23'
created: '2026-08-12'
modified: '2026-08-12'
tags:
- Company
- Marketing
- Marketing Automation
- CRM
- Email Marketing
- Sales
- Leads
- Campaigns
- Automation
- Software-as-a-Service
tags_raw:
- Company
- Marketing
- Marketing Automation
- CRM
- Email Marketing
- Sales
- Leads
- Campaigns
- Automation
- SaaS
apis:
- aid: sharpspring:open-api
  name: SharpSpring Open API
  description: The SharpSpring (Constant Contact Lead Gen & CRM) Open API — a single HTTPS POST endpoint that accepts a JSON
    envelope of method, params and id, very similar to JSON-RPC. Version v1 resolves timestamps against the Company Profile
    time zone; v1.2 handles all timestamps in UTC. Credentials are an account ID and secret key passed either as query-string
    parameters or as the X-Account-Id header plus an Authorization bearer token. Documented limits are 50,000 requests per
    day, 10 queries per second, and 500 queries per request.
  humanURL: https://knowledgebase.constantcontact.com/lead-gen-crm/articles/KnowledgeBase/50374-Understanding-Lead-Gen--CRM-Open-API-Overview?lang=en_US
  baseURL: https://api.sharpspring.com/pubapi/v1.2/
  tags:
  - Marketing Automation
  - CRM
  - Leads
  - JSON-RPC
  properties:
  - type: Documentation
    url: https://knowledgebase.constantcontact.com/lead-gen-crm/articles/KnowledgeBase/50374-Understanding-Lead-Gen--CRM-Open-API-Overview?lang=en_US
  - type: APIReference
    url: https://knowledgebase.constantcontact.com/lead-gen-crm/articles/KnowledgeBase/50564-Understanding-Lead-Gen--CRM-Open-API-Methods?lang=en_US
  - type: GettingStarted
    url: https://knowledgebase.constantcontact.com/lead-gen-crm/articles/KnowledgeBase/50404-Understanding-Lead-Gen-CRM-Open-API-Example-Code?lang=en_US
  - type: Authentication
    url: authentication/sharpspring-authentication.yml
  - type: ErrorCatalog
    url: errors/sharpspring-problem-types.yml
  - type: RateLimits
    url: rate-limits/sharpspring-rate-limits.yml
  - type: Conventions
    url: conventions/sharpspring-conventions.yml
  - type: DataModel
    url: data-model/sharpspring-data-model.yml
  - type: Webhooks
    url: asyncapi/sharpspring-postbacks-webhooks.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/sharpspring-domain-security.yml
- type: Website
  url: https://sharpspring.com/
- type: DeveloperPortal
  url: https://knowledgebase.constantcontact.com/lead-gen-crm/articles/KnowledgeBase/50374-Understanding-Lead-Gen--CRM-Open-API-Overview?lang=en_US
- type: Documentation
  url: https://knowledgebase.constantcontact.com/lead-gen-crm/articles/KnowledgeBase/50374-Understanding-Lead-Gen--CRM-Open-API-Overview?lang=en_US
- type: APIReference
  url: https://knowledgebase.constantcontact.com/lead-gen-crm/articles/KnowledgeBase/50564-Understanding-Lead-Gen--CRM-Open-API-Methods?lang=en_US
- type: GettingStarted
  url: https://knowledgebase.constantcontact.com/lead-gen-crm/articles/KnowledgeBase/50404-Understanding-Lead-Gen-CRM-Open-API-Example-Code?lang=en_US
- type: Support
  url: https://sharpspring.com/customer-support/
- type: HelpCenter
  url: https://knowledgebase.constantcontact.com/lead-gen-crm?lang=en_US
- type: Blog
  url: https://www.constantcontact.com/blog/
- type: GitHubOrganization
  url: https://github.com/sharpspring
- type: StatusPage
  url: https://status.sharpspring.com/
- type: Pricing
  url: https://sharpspring.com/agency-pricing/
- type: SignUp
  url: https://www.constantcontact.com/signup/lead-gen-crm/demo
- type: Login
  url: https://api.sharpspring.com/
- type: TermsOfService
  url: https://www.constantcontact.com/legal/terms
- type: PrivacyPolicy
  url: https://www.constantcontact.com/legal/privacy-notice
- type: Security
  url: https://www.constantcontact.com/disclosure
- type: Integrations
  url: https://sharpspring.com/app-marketplace/
- type: WellKnown
  url: well-known/sharpspring-well-known.yml
- type: SecurityTxt
  url: well-known/sharpspring-security.txt
- type: LLMsTxt
  url: llms/sharpspring-llms.txt
- type: Authentication
  url: authentication/sharpspring-authentication.yml
- type: Conventions
  url: conventions/sharpspring-conventions.yml
- type: ErrorCatalog
  url: errors/sharpspring-problem-types.yml
- type: RateLimits
  url: rate-limits/sharpspring-rate-limits.yml
- type: Plans
  url: plans/sharpspring-plans-pricing.yml
- type: Lifecycle
  url: lifecycle/sharpspring-lifecycle.yml
- type: Conformance
  url: conformance/sharpspring-conformance.yml
- type: DataModel
  url: data-model/sharpspring-data-model.yml
- type: Packages
  url: packages/sharpspring-packages.yml
- type: Webhooks
  url: asyncapi/sharpspring-postbacks-webhooks.yml
- type: VulnerabilityDisclosure
  url: security/sharpspring-vulnerability-disclosure.yml
x-vouched-by:
- Chili Piper
- Moosend
x-vouch-count: 2
x-enrichment:
  date: '2026-08-12'
  status: enriched
  artifacts_added: 15
  pass: local-v1

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