SendHub

SendHub is a business text messaging platform for SMS/MMS marketing campaigns, two-way texting, appointment reminders, bulk messaging, SMS surveys, group messaging, and VoIP calling, used by more than 10,000 businesses. It exposes a REST-like v1 API at api.sendhub.com for programmatically managing contacts, groups, messages, inbox threads, account settings, and enterprise users, authenticated with a line username and API key (query params) or HTTP Basic. Published plans run Lite $19/mo to Basic $100/mo plus a quoted Custom tier, and every tier lists API access, though the developer page still says API access is custom-plan only. SendHub also supports 100+ integrations via direct connectors and Zapier plus inbound-SMS webhooks, and is a New Era Technology company. Surfaced as a 500 Global portfolio company and enriched by the API Evangelist pipeline.

SendHub publishes 6 API contracts indexed on the APIs.io network, including Authentication API, Contact API, Group API, and 3 more. Tagged areas include Company, SMS, Messaging, Text Messaging, and Communications.

The SendHub catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.

SendHub’s developer surface includes documentation, API reference, pricing, engineering blog, support, signup flow, authentication, and 24 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

59.1/100 strong ▬ flat Agent 28/100 agent aware Front door AI 1/6 silent Heartbeat 50/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessPaid

1 published contract 3 Agent Skills

Company SMS Messaging Text Messaging Communications Marketing Webhook VoIP

What this lets a business do 1

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

Application Communications

AE-150

Thread

GET /v1/inbox

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 59.1/100 · strong

Contract Quality 11.4 / 19

Developer Ergonomics 9.9 / 15

Access Clarity 12.6 / 15

Operational Transparency 1.0 / 10

Contract Governance 2.9 / 9

Discoverability 5.5 / 8

Regulatory Posture 4.0 / 15

Create-or-Update Ergonomics 1.1 / 10

Agent readiness — 28/100 · 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 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 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

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

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.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)

6 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Operational Transparency scores 10.5 — up to +11.6 composite points
Contract Quality scores 60.9 — up to +9.8 composite points
Contract Governance scores 31.8 — up to +8.2 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/sendhub/apis.yml: open an issue on github.com/api-evangelist/sendhub to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OpenAPI

measured — observed by APIs.io (published)

APIs 6

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

SendHub Authentication API

SendHub Contact API

Create and manage contacts.

SendHub Group API

Create and manage groups.

SendHub Message API

Send and manage messages.

SendHub Profile API

View and manage your account and lines

SendHub Thread API

View and manage inbox threads.

Open Collections 6

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

SendHub Authentication API

OPEN COLLECTION

SendHub Authentication Contact API

OPEN COLLECTION

SendHub Authentication Group API

OPEN COLLECTION

SendHub Authentication Message API

OPEN COLLECTION

SendHub Authentication Profile API

OPEN COLLECTION

SendHub Authentication Thread API

OPEN COLLECTION

Agent Skills 3

Packaged agent skills for driving this provider's APIs from an AI assistant.

Manage contacts and groups

AGENT SKILL

Read the two-way texting inbox

AGENT SKILL

Send an SMS to contacts or groups

AGENT SKILL

SendHub API pricing

Prices published by SendHub, read 2026-10-28 from www.sendhub.com/pricing/.

Plan	Price
Lite (Monthly)	$19 Monthly* Includes: 500 SMS Per Month, 50 Max Recipients Per SMS, 100 Included Voice Minutes
Lite+ (Monthly)	$37 Monthly* Includes: 1000 SMS Per Month, 100 Max Recipients Per SMS, 100 Included Voice Minutes
Starter (Monthly)	$52 Monthly* Includes: 2000 SMS Per Month, 150 Max Recipients Per SMS, 100 Included Voice Minutes
Basic (Monthly)	$100 Monthly* Includes: 4000 SMS Per Month, 150 Max Recipients Per SMS, 250 Included Voice Minutes
Lite (Annual)	$219 Annually* Includes: 500 SMS Per Month
Lite+ (Annual)	$400 Annually* Includes: 1000 SMS Per Month
Starter (Annual)	$570 Annually* Includes: 2000 SMS Per Month
Basic (Annual)	$1,000 Annually* Includes: 4000 SMS Per Month

All 9 plans, limits and sources →

Billed by: subscription · FinOps profile →

Pricing Plans 2

Published pricing tiers and plan structures.

Sendhub Plans Pricing

9 plans

PLANS

Sendhub Price Estimates

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Sendhub Rate Limits

0 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

SendHub

SLA

FinOps 1

Cost, billing, and metering signals for API financial operations.

Sendhub Finops

FINOPS

Event Specifications 1

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

Sendhub Webhooks

ASYNCAPI

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

SendHub API Rules

59 rules · 49 errors 9 warnings 1 info

SPECTRAL

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Sendhub Openapi Overlay

2 actions · update · sendhub-openapi-original.yml

DERIVED

Security Posture 2

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

Sendhub Authentication

apiKey/http · 3 schemes

SECURITY

Sendhub Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Sendhub Agentic Access

28 operations · 14 acting

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

SignUp

SignUp

Login

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

X-MCPServerCandidate

X-MCPServerCandidate

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

ErrorCatalog

Conventions

DataModel

Lifecycle

Conformance

Webhooks

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

SDKs

SDKs

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

Support

Support

RateLimits

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

Other 2

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

Overlay

Overlay

Source (apis.yml)

aid: sendhub
name: SendHub
description: SendHub is a business text messaging platform for SMS/MMS marketing campaigns, two-way texting, appointment reminders,
  bulk messaging, SMS surveys, group messaging, and VoIP calling, used by more than 10,000 businesses. It exposes a REST-like
  v1 API at api.sendhub.com for programmatically managing contacts, groups, messages, inbox threads, account settings, and
  enterprise users, authenticated with a line username and API key (query params) or HTTP Basic. Published plans run Lite
  $19/mo to Basic $100/mo plus a quoted Custom tier, and every tier lists API access, though the developer page still says
  API access is custom-plan only. SendHub also supports 100+ integrations via direct connectors and Zapier plus inbound-SMS
  webhooks, and is a New Era Technology company. Surfaced as a 500 Global portfolio company and enriched by the API Evangelist
  pipeline.
url: https://raw.githubusercontent.com/api-evangelist/sendhub/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:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: paid
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Paid
  confidence: high
  source:
  - plans
  - authentication
  - rate-limits
  - security
  generated: '2026-11-06'
  method: derived
image: https://www.sendhub.com/wp-content/uploads/2019/01/faviconsendhub-150x150.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- 500-global
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-08-13'
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 2
  pass: local-v1
tags:
- Company
- SMS
- Messaging
- Text Messaging
- Communications
- Marketing
- Webhook
- VoIP
tags_raw:
- Company
- SMS
- Messaging
- Text Messaging
- Communications
- Marketing
- Webhooks
- VoIP
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- aid: sendhub:sendhub-authentication-api
  name: SendHub Authentication API
  description: Log in via Username & Password and "Sign In As User"
  humanURL: https://sendhub.com/developer/
  baseURL: https://api.sendhub.com
  tags:
  - Authentication
  properties:
  - type: OpenAPI
    url: openapi/sendhub-authentication-api-openapi.yml
  - type: Documentation
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
  - type: APIReference
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
- aid: sendhub:sendhub-contact-api
  name: SendHub Contact API
  description: Create and manage contacts.
  humanURL: https://sendhub.com/developer/
  baseURL: https://api.sendhub.com
  tags:
  - Contact
  properties:
  - type: OpenAPI
    url: openapi/sendhub-contact-api-openapi.yml
  - type: Documentation
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
  - type: APIReference
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
- aid: sendhub:sendhub-group-api
  name: SendHub Group API
  description: Create and manage groups.
  humanURL: https://sendhub.com/developer/
  baseURL: https://api.sendhub.com
  tags:
  - Group
  properties:
  - type: OpenAPI
    url: openapi/sendhub-group-api-openapi.yml
  - type: Documentation
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
  - type: APIReference
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
- aid: sendhub:sendhub-message-api
  name: SendHub Message API
  description: Send and manage messages.
  humanURL: https://sendhub.com/developer/
  baseURL: https://api.sendhub.com
  tags:
  - Message
  properties:
  - type: OpenAPI
    url: openapi/sendhub-message-api-openapi.yml
  - type: Documentation
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
  - type: APIReference
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
- aid: sendhub:sendhub-profile-api
  name: SendHub Profile API
  description: View and manage your account and lines
  humanURL: https://sendhub.com/developer/
  baseURL: https://api.sendhub.com
  tags:
  - Profiles
  tags_raw:
  - Profile
  properties:
  - type: OpenAPI
    url: openapi/sendhub-profile-api-openapi.yml
  - type: Documentation
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
  - type: APIReference
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
- aid: sendhub:sendhub-thread-api
  name: SendHub Thread API
  description: View and manage inbox threads.
  humanURL: https://sendhub.com/developer/
  baseURL: https://api.sendhub.com
  tags:
  - Threads
  tags_raw:
  - Thread
  properties:
  - type: OpenAPI
    url: openapi/sendhub-thread-api-openapi.yml
  - type: Documentation
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
  - type: APIReference
    url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
common:
- type: CapabilityMap
  url: capabilities/sendhub-capability-edges.yml
  name: SendHub Business Capability Map
- type: Website
  url: https://sendhub.com
- type: DeveloperPortal
  url: https://sendhub.com/developer/
- type: Documentation
  url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
- type: APIReference
  url: https://integrations.sendhub.com/SendHub-API-v1-Documentation.html
- type: Pricing
  url: https://sendhub.com/pricing/
- type: Blog
  url: https://sendhub.com/blogs/
- type: Support
  url: https://support.sendhub.com/hc/en-us
- type: SignUp
  url: https://app.sendhub.com/signup/
- type: Login
  url: https://app.sendhub.com/login
- type: TermsOfService
  url: https://sendhub.com/terms-of-use/
- type: PrivacyPolicy
  url: https://sendhub.com/privacy/
- type: GitHubOrganization
  url: https://github.com/sendhub
- type: Authentication
  url: authentication/sendhub-authentication.yml
- type: DomainSecurity
  url: security/sendhub-domain-security.yml
- type: AgenticAccess
  url: agentic-access/sendhub-agentic-access.yml
- type: Packages
  url: packages/sendhub-packages.yml
- type: SDKs
  url: packages/sendhub-packages.yml
- type: X-MCPServerCandidate
  url: mcp/sendhub-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: LLMsTxt
  url: llms/sendhub-llms.txt
- type: ErrorCatalog
  url: errors/sendhub-error-codes.yml
- type: Conventions
  url: conventions/sendhub-conventions.yml
- type: DataModel
  url: data-model/sendhub-data-model.yml
- type: Lifecycle
  url: lifecycle/sendhub-lifecycle.yml
- type: Conformance
  url: conformance/sendhub-conformance.yml
- type: Overlay
  url: overlays/sendhub-openapi-overlay.yaml
- type: Webhooks
  url: asyncapi/sendhub-webhooks.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Plans
  url: plans/sendhub-plans-pricing.yml
- type: RateLimits
  url: rate-limits/sendhub-rate-limits.yml
- type: GettingStarted
  url: https://www.sendhub.com/developer/

SendHub API — frequently asked questions

Does SendHub have an API?

Yes. APIs.io lists 6 APIs from SendHub, including SendHub Authentication API, SendHub Contact API and SendHub Group API, and 3 more.

Is there an OpenAPI specification for the SendHub API?

Yes. APIs.io indexes 6 OpenAPI specifications for SendHub, each linked for download from this page.

How do I authenticate with the SendHub API?

SendHub uses bearer-token authentication (apiKey/http · 3 schemes). The details are profiled on APIs.io as Sendhub Authentication.

How much does the SendHub API cost?

SendHub publishes its prices; its Lite (Monthly) plan is $19 Monthly* as of 2026-10-28. APIs.io lists 9 pricing plans for SendHub, with each plan's price, limits and inclusions under Pricing on this page.

Is the SendHub API ready for AI agents?

SendHub has a Kin Score of 59.1 out of 100 (strong) and an Agent Readiness score of 28.1 (agent-aware), scored by API Evangelist on 2026-11-06.

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