ClickSend SMS

ClickSend is a global business communications platform for sending and receiving SMS, MMS, voice, email, fax, and physical post via API or web dashboard, with direct carrier routing and a 99.95% uptime SLA. The ClickSend REST API v3 provides endpoints for SMS, MMS, voice, email, fax, post letters, contacts, accounts, and webhooks, secured with HTTP Basic Authentication using a username and API key.

ClickSend SMS publishes 1 API on the APIs.io network: Sms API. Tagged areas include SMS, MMS, Messaging, Voice, and Email.

ClickSend SMS’s developer surface includes authentication, documentation, pricing, signup flow, engineering blog, and 6 more developer resources.

🌐 Visit website 📡 Source on GitHub

28.6/100 thin ▬ flat Agent 26/100 agent aware Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0

AccessSelf serve

1 APIs

SMS MMS Messaging Voice Email Fax Direct Mail Communications

Kin Score

Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0

Composite quality — 28.6/100 · thin

Contract Quality 9.8 / 21

Developer Ergonomics 4.0 / 17

Access Clarity 5.4 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.0 / 10

Discoverability 5.8 / 9

Regulatory Posture 3.5 / 15

Agent readiness — 26/100 · agent aware

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 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 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

Regulatory Posture applies to this provider. Its tags matched the Telecommunications 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.

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/. This rating is computed from github.com/api-evangelist/clicksend-sms: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 1

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

Get Started 1

Portal, sign-up, and the first successful call

Signup

Signup

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Access & Security 3

Authentication, authorization, and security posture

TrustCenter

TrustCenter

DomainSecurity

DomainSecurity

Authentication

Authentication

Commercial 1

Pricing, plans, and the legal terms of use

Pricing

Pricing

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Knowledge Base

Knowledge Base

Source (apis.yml)

aid: clicksend-sms
name: ClickSend SMS
description: ClickSend is a global business communications platform for sending and receiving SMS, MMS, voice, email, fax,
  and physical post via API or web dashboard, with direct carrier routing and a 99.95% uptime SLA. The ClickSend REST API
  v3 provides endpoints for SMS, MMS, voice, email, fax, post letters, contacts, accounts, and webhooks, secured with HTTP
  Basic Authentication using a username and API key.
type: Index
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/clicksend-sms.png
tags:
- SMS
- MMS
- Messaging
- Voice
- Email
- Fax
- Direct Mail
- Communications
url: https://raw.githubusercontent.com/api-evangelist/clicksend-sms/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-05-11'
specificationVersion: '0.23'
apis:
- aid: clicksend-sms:clicksend-sms-sms-api
  name: ClickSend SMS Sms API
  description: The Sms API from ClickSend SMS — 6 operation(s) for sms.
  humanURL: https://developers.clicksend.com/docs/
  baseURL: https://rest.clicksend.com/v3
  tags:
  - SMS
  tags_raw:
  - Sms
  properties:
  - type: OpenAPI
    url: openapi/clicksend-sms-sms-api-openapi.yml
  - type: Documentation
    url: https://developers.clicksend.com/docs/
  - type: API Portal
    url: https://developers.clicksend.com/
  - type: GitHubOrganization
    url: https://github.com/ClickSend
common:
- type: AgenticAccess
  url: agentic-access/clicksend-sms-agentic-access.yml
- type: TrustCenter
  url: security/clicksend-sms-trust-center.yml
- type: DomainSecurity
  url: security/clicksend-sms-domain-security.yml
- type: Authentication
  url: authentication/clicksend-sms-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/clicksend
- type: Website
  url: https://www.clicksend.com
- type: Documentation
  url: https://developers.clicksend.com/
- type: Pricing
  url: https://www.clicksend.com/en/pricing/
- type: Signup
  url: https://dashboard.clicksend.com/signup
- type: Knowledge Base
  url: https://help.clicksend.com
- type: Integrations
  url: https://integrations.clicksend.com/
- type: Blog
  url: https://blog.clicksend.com
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

ClickSend SMS

Kin Score

APIs 1

ClickSend SMS Sms API

Open Collections 3

API Collection

ClickSend REST API v3 Sms API

ClickSend SMS REST API v3

Security Posture 3

Clicksend Sms Authentication

Clicksend Sms Domain Security

Clicksend Sms Trust Center

Agentic Access 1

Clicksend Sms Agentic Access

Resources