# ClickSend

**Canonical:** https://apis.io/providers/clicksend/  
**Website:** https://www.clicksend.com/  
**APIs profiled:** 10

ClickSend is a cloud communications company providing a single REST API for business messaging across SMS, MMS, voice / text-to-speech, transactional email, and physical post - letters and postcards printed and mailed globally. The v3 API (rest.clicksend.com/v3) uses HTTP Basic authentication with a username and API key and covers sending, delivery receipts, inbound handling, contacts and lists, and account balance.

## Kin Score — 37.5 / 100 (thin)

Scored 2026-08-24 under rubric 0.13.0. Trend: flat (-0.3 from 37.8).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 49.0 |
| Governance | 0.0 |
| Contract Governance | 0.0 |
| Operational Transparency | 34.2 |
| Developer Ergonomics | 23.8 |
| Commercial Clarity | 47.4 |
| Access Clarity | 47.4 |

Regulatory layer — **Telecommunications**: 23.6 (matched via tags).

## Agent readiness — 21.5 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | documented |
| MCP Server | no |
| Auth Clarity | bearer |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## Access

Paid · Self-serve signup — onboarding: self-serve, pricing: paid, trial: no (confidence: high).

## APIs (10)

- **ClickSend Account API** — Account details, usage, and balance.
- **ClickSend Contact API** — Manage contacts.
- **ClickSend ContactList API** — Manage contact lists.
- **ClickSend Email API** — Send and view transactional email.
- **ClickSend MMS API** — Send and view MMS messages.
- **ClickSend Post Letter API** — Print and mail physical letters.
- **ClickSend Post Postcard API** — Print and mail physical postcards.
- **ClickSend Receipts API** — Delivery receipts, inbound messages, and automations.
- **ClickSend SMS API** — Send and view SMS messages.
- **ClickSend Voice API** — Send and view voice (text-to-speech) messages.

## Agentic access (1)

- **Clicksend Agentic Access** — 42 operations · 22 acting

## Security (3)

- **Clicksend Authentication** — http · 1 scheme
- **Clicksend Domain Security** — TLSv1.2 · DMARC
- **Clicksend Trust Center** — SOC 2, ISO 27001, PCI DSS, HIPAA, GDPR

## Plans (1)

- **Clicksend Plans Pricing**

## Tags

Communications, SMS, MMS, Voice, Email, Messaging, CPaaS

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/clicksend/). Scores are computed from the provider's own public artifacts under a published rubric.