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

48.4/100 developing ▬ flat Agent 25/100 agent aware Front door AI 1/6 silent saas Full breakdown ↓
scored 2026-09-25 · rubric v0.23.0

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 2026-09-25 · rubric v0.23.0

Composite quality — 48.4/100 · developing

Contract Quality 8.3 / 21

Developer Ergonomics 9.7 / 17

Access Clarity 7.6 / 17

Operational Transparency 7.6 / 11

Contract Governance 0.5 / 10

Discoverability 5.6 / 9

Regulatory Posture 4.6 / 15

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

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

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.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/sharpspring"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/sharpspring/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/sharpspring/evidence"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.