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 5 APIs on the APIs.io network, including Broadcast API, Contacts API, SMS API, and 2 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, API reference, getting-started guide, and 21 more developer resources.

🌐 Visit website 📡 Source on GitHub

56.9/100 strong ▬ flat Agent 38/100 agent ready Front door AI 6/6 dominant saas Full breakdown ↓
scored 2026-09-19 · rubric v0.22.0

AccessFreemiumSelf serveFree trial⚡ Free to try

1 APIs 1 MCP Servers

Company SMS Messaging Marketing Automation Customer Engagement Taiwan Omnichannel MCP

Kin Score

Kin Score How this is scored →
scored 2026-09-19 · rubric v0.22.0

Composite quality — 56.9/100 · strong

Contract Quality 9.9 / 19

Developer Ergonomics 12.1 / 15

Access Clarity 11.4 / 15

Operational Transparency 3.1 / 10

Contract Governance 0.4 / 9

Discoverability 5.7 / 8

Regulatory Posture 5.2 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 38/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

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 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

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/.

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/crescendo-lab: 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 5

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).

Crescendo Lab MAAC Go API

The MAAC Go API API from Crescendo Lab — 0 operation(s) for maac go api.

Open Collections 5

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

API Collection

OPEN COLLECTION

MAAC Go Broadcast API

OPEN COLLECTION

MAAC Go Broadcast Contacts API

OPEN COLLECTION

MAAC Go Broadcast SMS API

OPEN COLLECTION

MAAC Go Broadcast Teams API

OPEN COLLECTION

MCP Servers 1

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

MAAC Go MCP

Official hosted + local MCP server for MAAC Go (Crescendo Lab's self-serve Taiwan SMS platform). Lets Claude / Cursor / Windsurf / Codex send SMS, run broadcasts, pull logs, and...

MCP SERVER

Pricing Plans 1

Published pricing tiers and plan structures.

Crescendo Lab Plans Pricing

8 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Crescendo Lab Rate Limits

2 limits

RATE LIMITS

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 5

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

SignUp

SignUp

Login

GettingStarted

GettingStarted

Sandbox

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

MCPServer

MCPServer

AgentSkill

AgentSkill

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Conventions

Conventions

Idempotency

Idempotency

Build 5

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

SDKs

Packages

CLI

ToolCrosswalk

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

HelpCenter

HelpCenter

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 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: crescendo-lab
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: true
  try_now: true
  public: false
  label: Freemium (free trial) · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  - rate-limits
  - security
  - sandbox
  generated: '2026-09-03'
  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: '0.23'
created: '2026-07-17'
modified: '2026-08-13'
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:
  - Team
  tags_raw:
  - 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
- aid: crescendo-lab:crescendo-lab-maac-go-api-api
  name: Crescendo Lab MAAC Go API
  description: The MAAC Go API API from Crescendo Lab — 0 operation(s) for maac go api.
  humanURL: https://sms.cresclab.com/developers.html
  baseURL: https://sms.cresclab.com/api
  tags:
  - MAAC Go API
  properties:
  - type: OpenAPI
    url: openapi/crescendo-lab-maac-go-api-api-openapi.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Overlay
  url: overlays/crescendo-lab-maacgo-overlay.yaml
- 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/signup.html
- type: Login
  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: ToolCrosswalk
  url: mcp/crescendo-lab-tool-crosswalk.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Plans
  url: plans/crescendo-lab-plans-pricing.yml
- type: RateLimits
  url: rate-limits/crescendo-lab-rate-limits.yml
- type: APIReference
  url: https://sms.cresclab.com/openapi.yaml
- type: GettingStarted
  url: https://sms.cresclab.com/developers.html
- type: Sandbox
  url: sandbox/crescendo-lab-sandbox.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
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 5
  pass: local-v1
  note: WellKnown pointer removed 2026-08-13 — well-known/crescendo-lab-well-known.yml records 18 probes across both hosts
    and every one returned 404, so the artifact documents an absence and must not assert a served surface.

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