CallChatSyn

CallChatSyn is an AI receptionist and 24/7 answering service for small businesses. A pre-trained voice and messaging agent answers business calls, WhatsApp and website chat day and night, handles common questions and books appointments, with flat monthly pricing in Singapore dollars (S$69/mo for up to 80 calls; website chat only from S$39/mo). The CallChatSyn API exposes a business's answering bot, order status and booking calendar to its own website, app or AI agent, described by a public OpenAPI document and an MCP endpoint.

CallChatSyn publishes 3 API contracts indexed on the APIs.io network: Answer API, Bookings API, and Slots API. Tagged areas include Company, AI Receptionist, Answering Service, Voice AI, and Appointment Booking.

The CallChatSyn catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

CallChatSyn’s developer surface includes sandbox, getting-started guide, authentication, documentation, signup flow, and 24 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

44.5/100 developing Agent 34/100 agent ready Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 published contract 1 MCP Servers 1 Agent Skills

Company AI Receptionist Answering Service Voice AI Appointment Booking Chatbots WhatsApp Small Business MCP

Kin Score

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

Composite quality — 44.5/100 · developing

Contract Quality 6.5 / 21

Developer Ergonomics 8.2 / 17

Access Clarity 7.7 / 17

Operational Transparency 3.1 / 11

Contract Governance 6.4 / 10

Discoverability 5.5 / 9

Regulatory Posture 3.1 / 15

Agent readiness — 34/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 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 0 / 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 AI & Biometrics 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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

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/.

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

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)
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks

6 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 30.7 — up to +17.3 composite points
Access Clarity scores 45.5 — up to +10.9 composite points
Developer Ergonomics scores 48.1 — up to +10.4 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/callchatsyn-com/apis.yml: open an issue on github.com/api-evangelist/callchatsyn-com 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 2

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.

Model Context Protocol (MCP)

measured — observed by APIs.io (documented)

OpenAPI

measured — observed by APIs.io (published)

APIs 3

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

CallChatSyn Answer API

The Answer API from CallChatSyn — 1 operation(s) for answer.

CallChatSyn Bookings API

The Bookings API from CallChatSyn — 2 operation(s) for bookings.

CallChatSyn Slots API

The Slots API from CallChatSyn — 1 operation(s) for slots.

MCP Servers 1

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

CallChatSyn MCP Server

Remote MCP server at callchatsyn.com requiring an API key; 4 tools listed.

MCP SERVER

Agent Skills 1

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

answer-and-book-a-customer

AGENT SKILL

Pricing Plans 1

Published pricing tiers and plan structures.

Callchatsyn Com Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Callchatsyn Com Rate Limits

4 limits

RATE LIMITS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Callchatsyn Com Context

1 classes · 1 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

CallChatSyn API Rules

42 rules · 40 errors 1 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.

Callchatsyn Com Openapi Overlay

5 actions · documentation · callchatsyn-com-openapi.yml

GENERATED

Security Posture 2

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

Callchatsyn Com Authentication

http · 2 schemes

SECURITY

Callchatsyn Com Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Callchatsyn Com Agentic Access

4 operations · 3 acting

AGENTIC

Resources

Get Started 5

Portal, sign-up, and the first successful call

Sandbox

GettingStarted

DeveloperPortal

SignUp

Login

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

AgentSkill

AgentSkill

MCPServer

MCPServer

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Lifecycle

ErrorCatalog

Conformance

Scroll for all 7

Build 3

SDKs, sample code, and the tooling you integrate with

ToolCrosswalk

ToolCrosswalk

SDKs

SDKs

Packages

Packages

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 1

The organization behind the API

Website

Website

Other 3

Properties that don't map to a standard resource type

Overlay

Overlay

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: callchatsyn-com
name: CallChatSyn
description: CallChatSyn is an AI receptionist and 24/7 answering service for small businesses. A pre-trained voice and messaging
  agent answers business calls, WhatsApp and website chat day and night, handles common questions and books appointments,
  with flat monthly pricing in Singapore dollars (S$69/mo for up to 80 calls; website chat only from S$39/mo). The CallChatSyn
  API exposes a business's answering bot, order status and booking calendar to its own website, app or AI agent, described
  by a public OpenAPI document and an MCP endpoint.
url: https://artifacts.apis.io/callchatsyn-com/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-11-03 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-11-03'
modified: '2026-11-03'
tags:
- Company
- AI Receptionist
- Answering Service
- Voice AI
- Appointment Booking
- Chatbots
- WhatsApp
- Small Business
- MCP
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
image: https://callchatsyn.com/og-image.png
common:
- type: AgenticAccess
  url: agentic-access/callchatsyn-com-agentic-access.yml
- type: RateLimits
  url: rate-limits/callchatsyn-com-rate-limits.yml
- type: Plans
  url: plans/callchatsyn-com-plans-pricing.yml
- type: Spectral
  url: rules/callchatsyn-com-rules.yml
- type: JSONLD
  url: json-ld/callchatsyn-com-context.jsonld
- type: Vocabulary
  url: vocabulary/callchatsyn-com-vocabulary.yml
- type: AgentSkill
  url: skills/_index.yml
- type: DataModel
  url: data-model/callchatsyn-com-data-model.yml
- type: Sandbox
  url: sandbox/callchatsyn-com-sandbox.yml
- type: Lifecycle
  url: lifecycle/callchatsyn-com-lifecycle.yml
- type: ErrorCatalog
  url: errors/callchatsyn-com-problem-types.yml
- type: Conformance
  url: conformance/callchatsyn-com-conformance.yml
- type: Overlay
  url: overlays/callchatsyn-com-openapi-overlay.yaml
- type: ToolCrosswalk
  url: mcp/callchatsyn-com-tool-crosswalk.yml
- type: MCPServer
  url: mcp/callchatsyn-com-mcp.yml
- type: Hosts
  url: hosts/callchatsyn-com-hosts.yml
- type: Vendors
  url: vendors/callchatsyn-com-vendors.yml
- type: SDKs
  url: packages/callchatsyn-com-packages.yml
- type: Packages
  url: packages/callchatsyn-com-packages.yml
- type: GettingStarted
  url: https://callchatsyn.com/setup
- type: Authentication
  url: authentication/callchatsyn-com-authentication.yml
- type: Website
  url: https://callchatsyn.com/
- type: DomainSecurity
  url: security/callchatsyn-com-domain-security.yml
- type: DeveloperPortal
  url: https://callchatsyn.com/developers
- type: Documentation
  url: https://callchatsyn.com/developers/whatsapp
- type: SignUp
  url: https://callchatsyn.com/signup
- type: Login
  url: https://callchatsyn.com/login
- type: TermsOfService
  url: https://callchatsyn.com/terms
- type: PrivacyPolicy
  url: https://callchatsyn.com/privacy
apis:
- aid: callchatsyn-com:callchatsyn-com-answer-api
  name: CallChatSyn Answer API
  description: The Answer API from CallChatSyn — 1 operation(s) for answer.
  humanURL: https://callchatsyn.com/developers
  baseURL: https://callchatsyn.com
  tags:
  - Answer
  properties:
  - type: OpenAPI
    url: openapi/callchatsyn-com-answer-api-openapi.yml
  - type: Documentation
    url: https://callchatsyn.com/developers
- aid: callchatsyn-com:callchatsyn-com-bookings-api
  name: CallChatSyn Bookings API
  description: The Bookings API from CallChatSyn — 2 operation(s) for bookings.
  humanURL: https://callchatsyn.com/developers
  baseURL: https://callchatsyn.com
  tags:
  - Bookings
  properties:
  - type: OpenAPI
    url: openapi/callchatsyn-com-bookings-api-openapi.yml
  - type: Documentation
    url: https://callchatsyn.com/developers
- aid: callchatsyn-com:callchatsyn-com-slots-api
  name: CallChatSyn Slots API
  description: The Slots API from CallChatSyn — 1 operation(s) for slots.
  humanURL: https://callchatsyn.com/developers
  baseURL: https://callchatsyn.com
  tags:
  - Slots
  properties:
  - type: OpenAPI
    url: openapi/callchatsyn-com-slots-api-openapi.yml
  - type: Documentation
    url: https://callchatsyn.com/developers
x-coverage:
  state: covered
  reason: identity-verified
  detail: Name, description, image and link pointers taken from callchatsyn.com (title "... | CallChatSyn", og:site_name CallChatSyn,
    footer "© 2026 CallChatSyn"). Login/SignUp recorded from preflight site_links (200), not re-fetched per probe-safety rules.
  evidence:
  - url: https://callchatsyn.com/
    status: 200
  - url: https://callchatsyn.com/developers
    status: 200
  - url: https://callchatsyn.com/developers/whatsapp
    status: 200
  - url: https://callchatsyn.com/terms
    status: 200
  - url: https://callchatsyn.com/privacy
    status: 200
  - url: https://callchatsyn.com/og-image.png
    status: 200
x-enrichment:
  date: '2026-11-03'
  status: enriched
  artifacts_added: 28
  pass: modular-v1
  engine: identity=anthropic,contract=anthropic,surfaces=anthropic,docs=anthropic,regulatory=anthropic

CallChatSyn API — frequently asked questions

Does CallChatSyn have an API?

Yes. APIs.io lists 3 APIs from CallChatSyn, including CallChatSyn Answer API, CallChatSyn Bookings API and CallChatSyn Slots API.

Is there an OpenAPI specification for the CallChatSyn API?

Yes. APIs.io indexes 3 OpenAPI specifications for CallChatSyn, each linked for download from this page.

How do I authenticate with the CallChatSyn API?

CallChatSyn uses bearer-token authentication (http · 2 schemes). The details are profiled on APIs.io as Callchatsyn Com Authentication.

How much does the CallChatSyn API cost?

APIs.io lists 4 pricing plans for CallChatSyn, with each plan's price, limits and inclusions under Pricing on this page.

Does CallChatSyn have an MCP server?

Yes. APIs.io lists 1 MCP server for CallChatSyn: Remote MCP server at callchatsyn.com requiring an API key; 4 tools listed.

Is the CallChatSyn API ready for AI agents?

CallChatSyn has a Kin Score of 44.5 out of 100 (developing) and an Agent Readiness score of 33.7 (agent-ready), scored by API Evangelist on 2026-11-06.

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