Crescendo Lab website screenshot

Crescendo Lab

Crescendo Lab is a Taiwan-based, Asia-leading AI omnichannel customer communication software company (cresclab.com) serving 800+ global brands, and a LINE Biz-Solutions Gold Partner. Its platform spans MAAC (AI marketing automation), CAAC (conversational applications), and DAAC (data intelligence) across LINE, WhatsApp, SMS, email, and social channels. Its developer-facing surface is MAAC Go (sms.cresclab.com) — a self-serve, NCC-compliant Taiwan SMS API with a published OpenAPI spec, first-party Node/Python SDKs, a CLI, an official MCP server, and delivery webhooks. Surfaced as a 500 Global portfolio company and enriched into the API Evangelist network.

Crescendo Lab publishes 4 APIs on the APIs.io network, including Broadcast API, Contacts API, SMS API, and 1 more. Tagged areas include Company, SMS, Messaging, Marketing Automation, and Customer Engagement.

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

Crescendo Lab’s developer surface includes documentation, engineering blog, pricing, signup flow, CLI, authentication, and 15 more developer resources.

🌐 Visit website 📡 Source on GitHub
45.5/100 developing ▬ flat Agent 61/100 agent native Full breakdown ↓
scored 2026-08-10 · rubric v0.9.1
AccessSelf serve
4 APIs 1 MCP Servers
CompanySMSMessagingMarketing AutomationCustomer EngagementTaiwanOmnichannelMCP

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-10 · rubric v0.9.1
Composite quality — 45.5/100 · developing
Contract Quality 16.7 / 25
Developer Ergonomics 11.6 / 20
Commercial Clarity 8.9 / 20
Operational Transparency 0.7 / 13
Governance 1.4 / 12
Discoverability 9.3 / 10
Agent readiness — 61/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 10
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 7 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 5 / 5
Well-Known Catalog 4 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
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/crescendo-lab: 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 4

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

Crescendo Lab Broadcast API

Bulk (1-to-many) SMS. Small batches dispatch inline; >30 recipients queue asynchronously.

Crescendo Lab Contacts API

Address book with NCC-consent tracking.

Crescendo Lab SMS API

Transactional (1-to-1) SMS send + status.

Crescendo Lab Teams API

Cost-attribution teams. Tag sends with a team to see which team sent/spent how much (shared wallet — reporting only, not a wallet split).

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

crescendo-lab-mcp.yml

MCP SERVER

Event Specifications 1

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

Crescendo Lab Maacgo Webhooks

ASYNCAPI

Security Posture 2

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

Crescendo Lab Authentication

http · 1 scheme

SECURITY

Crescendo Lab Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 2

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 SignUp
SignUp

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt
LLMsTxt
 MCPServer
MCPServer
 AgentSkill
AgentSkill
 WellKnown
WellKnown

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Conventions
Conventions
 Idempotency
Idempotency

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 SDKs
SDKs
 Packages
Packages
 CLI
CLI

Access & Security 2

Authentication, authorization, and security posture

Authentication
Authentication
 DomainSecurity
DomainSecurity

Operate 1

Status, limits, changes, and where to get help

HelpCenter
HelpCenter

Commercial 3

Pricing, plans, and the legal terms of use

Pricing
Pricing
 TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: crescendo-lab
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/crescendo-lab.png
name: Crescendo Lab
description: Crescendo Lab is a Taiwan-based, Asia-leading AI omnichannel customer communication software company (cresclab.com)
  serving 800+ global brands, and a LINE Biz-Solutions Gold Partner. Its platform spans MAAC (AI marketing automation), CAAC
  (conversational applications), and DAAC (data intelligence) across LINE, WhatsApp, SMS, email, and social channels. Its
  developer-facing surface is MAAC Go (sms.cresclab.com) — a self-serve, NCC-compliant Taiwan SMS API with a published OpenAPI
  spec, first-party Node/Python SDKs, a CLI, an official MCP server, and delivery webhooks. Surfaced as a 500 Global portfolio
  company and enriched into the API Evangelist network.
url: https://raw.githubusercontent.com/api-evangelist/crescendo-lab/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- 500-global
x-tier: enriched
x-tier-reason: portfolio-lead-enriched
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-18'
tags:
- Company
- SMS
- Messaging
- Marketing Automation
- Customer Engagement
- Taiwan
- Omnichannel
- MCP
apis:
- aid: crescendo-lab:crescendo-lab-broadcast-api
  name: Crescendo Lab Broadcast API
  description: Bulk (1-to-many) SMS. Small batches dispatch inline; >30 recipients queue asynchronously.
  humanURL: https://sms.cresclab.com/developers.html
  baseURL: https://sms.cresclab.com/api
  tags:
  - Broadcast
  properties:
  - type: OpenAPI
    url: openapi/crescendo-lab-broadcast-api-openapi.yml
  - type: Webhooks
    url: asyncapi/crescendo-lab-maacgo-webhooks.yml
  - type: ErrorCatalog
    url: errors/crescendo-lab-problem-types.yml
  - type: Lifecycle
    url: lifecycle/crescendo-lab-lifecycle.yml
  - type: Conformance
    url: conformance/crescendo-lab-conformance.yml
  - type: DataModel
    url: data-model/crescendo-lab-data-model.yml
  - type: Sandbox
    url: sandbox/crescendo-lab-sandbox.yml
  - type: Documentation
    url: https://sms.cresclab.com/developers.html#api
  - type: APIReference
    url: https://sms.cresclab.com/openapi.yaml
  - type: GettingStarted
    url: https://sms.cresclab.com/developers.html
- aid: crescendo-lab:crescendo-lab-contacts-api
  name: Crescendo Lab Contacts API
  description: Address book with NCC-consent tracking.
  humanURL: https://sms.cresclab.com/developers.html
  baseURL: https://sms.cresclab.com/api
  tags:
  - Contacts
  properties:
  - type: OpenAPI
    url: openapi/crescendo-lab-contacts-api-openapi.yml
  - type: Webhooks
    url: asyncapi/crescendo-lab-maacgo-webhooks.yml
  - type: ErrorCatalog
    url: errors/crescendo-lab-problem-types.yml
  - type: Lifecycle
    url: lifecycle/crescendo-lab-lifecycle.yml
  - type: Conformance
    url: conformance/crescendo-lab-conformance.yml
  - type: DataModel
    url: data-model/crescendo-lab-data-model.yml
  - type: Sandbox
    url: sandbox/crescendo-lab-sandbox.yml
  - type: Documentation
    url: https://sms.cresclab.com/developers.html#api
  - type: APIReference
    url: https://sms.cresclab.com/openapi.yaml
  - type: GettingStarted
    url: https://sms.cresclab.com/developers.html
- aid: crescendo-lab:crescendo-lab-sms-api
  name: Crescendo Lab SMS API
  description: Transactional (1-to-1) SMS send + status.
  humanURL: https://sms.cresclab.com/developers.html
  baseURL: https://sms.cresclab.com/api
  tags:
  - SMS
  properties:
  - type: OpenAPI
    url: openapi/crescendo-lab-sms-api-openapi.yml
  - type: Webhooks
    url: asyncapi/crescendo-lab-maacgo-webhooks.yml
  - type: ErrorCatalog
    url: errors/crescendo-lab-problem-types.yml
  - type: Lifecycle
    url: lifecycle/crescendo-lab-lifecycle.yml
  - type: Conformance
    url: conformance/crescendo-lab-conformance.yml
  - type: DataModel
    url: data-model/crescendo-lab-data-model.yml
  - type: Sandbox
    url: sandbox/crescendo-lab-sandbox.yml
  - type: Documentation
    url: https://sms.cresclab.com/developers.html#api
  - type: APIReference
    url: https://sms.cresclab.com/openapi.yaml
  - type: GettingStarted
    url: https://sms.cresclab.com/developers.html
- aid: crescendo-lab:crescendo-lab-teams-api
  name: Crescendo Lab Teams API
  description: Cost-attribution teams. Tag sends with a team to see which team sent/spent how much (shared wallet — reporting
    only, not a wallet split).
  humanURL: https://sms.cresclab.com/developers.html
  baseURL: https://sms.cresclab.com/api
  tags:
  - Teams
  properties:
  - type: OpenAPI
    url: openapi/crescendo-lab-teams-api-openapi.yml
  - type: Webhooks
    url: asyncapi/crescendo-lab-maacgo-webhooks.yml
  - type: ErrorCatalog
    url: errors/crescendo-lab-problem-types.yml
  - type: Lifecycle
    url: lifecycle/crescendo-lab-lifecycle.yml
  - type: Conformance
    url: conformance/crescendo-lab-conformance.yml
  - type: DataModel
    url: data-model/crescendo-lab-data-model.yml
  - type: Sandbox
    url: sandbox/crescendo-lab-sandbox.yml
  - type: Documentation
    url: https://sms.cresclab.com/developers.html#api
  - type: APIReference
    url: https://sms.cresclab.com/openapi.yaml
  - type: GettingStarted
    url: https://sms.cresclab.com/developers.html
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://cresclab.com
- type: DeveloperPortal
  url: https://sms.cresclab.com/developers.html
- type: Documentation
  url: https://sms.cresclab.com/developers.html#api
- type: Blog
  url: https://blog.cresclab.com/zh-tw
- type: HelpCenter
  url: https://crescendolab.zendesk.com/hc/zh-tw
- type: Pricing
  url: https://cresclab.com/pricing
- type: SignUp
  url: https://sms.cresclab.com/app.html
- type: TermsOfService
  url: https://sms.cresclab.com/terms.html
- type: PrivacyPolicy
  url: https://sms.cresclab.com/privacy.html
- type: GitHubOrganization
  url: https://github.com/Crescendo-Lab
- type: LLMsTxt
  url: llms/crescendo-lab-llms.txt
- type: SDKs
  url: packages/crescendo-lab-packages.yml
- type: Packages
  url: packages/crescendo-lab-packages.yml
- type: CLI
  url: cli/crescendo-lab-cli.yml
- type: MCPServer
  url: mcp/crescendo-lab-mcp.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Authentication
  url: authentication/crescendo-lab-authentication.yml
- type: Conventions
  url: conventions/crescendo-lab-conventions.yml
- type: Idempotency
  url: conventions/crescendo-lab-conventions.yml
- type: DomainSecurity
  url: security/crescendo-lab-domain-security.yml
- type: WellKnown
  url: well-known/crescendo-lab-well-known.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence