JustCall

JustCall is a cloud-based phone system and contact center platform that provides voice calling, SMS/MMS messaging, IVR, call analytics, and contact management for small and mid-sized businesses. The platform integrates with CRMs, helpdesks, and automation tools. JustCall exposes REST APIs and webhooks for programmatically managing calls, SMS, contacts, phone numbers, and call dispositions, authenticated via API key plus API secret in headers.

JustCall publishes 4 API contracts indexed on the APIs.io network, including Calls API, Contacts API, SMS API, and 1 more. Tagged areas include Voice, SMS, Cloud Phone, Contact Center, and Telephony.

JustCall’s developer surface includes authentication, documentation, pricing, signup flow, support, engineering blog, and 8 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

34.3/100 thin ▬ flat Agent 30/100 agent ready Front door AI 6/6 dominant saas Full breakdown ↓
scored 2026-10-17 · rubric v0.24.0

1 published contract 1 MCP Servers

Voice SMSCloud PhoneContact Center Telephony Communications

What this lets a business do 1

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

Customer Service Management

BC-430

Calls

GET /calls

Kin Score

Kin Score How this is scored →
scored 2026-10-17 · rubric v0.24.0

Composite quality — 34.3/100 · thin

Contract Quality 9.1 / 19

Developer Ergonomics 6.8 / 15

Access Clarity 4.7 / 15

Operational Transparency 0.8 / 10

Contract Governance 0.0 / 9

Discoverability 5.6 / 8

Regulatory Posture 2.1 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 30/100 · 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 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 6 / 6

Agent Skills 0 / 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/justcall: 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 →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Customer Support, Helpdesk and Contact Center	builds-on	43.4	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

APIs 4

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

JustCall REST API

REST API for placing calls, sending SMS and MMS messages, managing contacts, phone numbers, users, and call dispositions in JustCall. Authentication uses an API key and API secr...

JustCall Calls API

Manage and query voice calls handled through JustCall.

JustCall Contacts API

Create and manage contacts in the JustCall directory.

JustCall SMS API

Send and manage SMS/MMS messages.

Open Collections 5

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

API Collection

OPEN COLLECTION

JustCall REST Calls API

OPEN COLLECTION

JustCall REST Calls Contacts API

OPEN COLLECTION

JustCall REST Calls SMS API

OPEN COLLECTION

JustCall REST API

OPEN COLLECTION

MCP Servers 1

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

JustCall MCP Server

Remote MCP server at developer.justcall.io over HTTP.

MCP SERVER

Security Posture 3

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

Justcall Authentication

apiKey · 1 scheme

SECURITY

Justcall Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Justcall Trust Center

SOC 2, ISO 27001, PCI DSS, HIPAA, CSA STAR

SECURITY

Agentic Access 1

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

Justcall Agentic Access

3 operations · 2 acting

AGENTIC

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 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LlmsText

LlmsText

Access & Security 3

Authentication, authorization, and security posture

TrustCenter

TrustCenter

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 1

Status, limits, changes, and where to get help

Support

Support

Commercial 1

Pricing, plans, and the legal terms of use

Pricing

Pricing

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

Source (apis.yml)

aid: justcall
name: JustCall
description: JustCall is a cloud-based phone system and contact center platform that provides voice calling, SMS/MMS messaging,
  IVR, call analytics, and contact management for small and mid-sized businesses. The platform integrates with CRMs, helpdesks,
  and automation tools. JustCall exposes REST APIs and webhooks for programmatically managing calls, SMS, contacts, phone
  numbers, and call dispositions, authenticated via API key plus API secret in headers.
type: Index
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: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/justcall.png
x-docs-platform: readme
x-docs-platform-confidence: high
x-docs-platform-checked: 2026-10-03
tags:
- Voice
- SMS
- Cloud Phone
- Contact Center
- Telephony
- Communications
url: https://raw.githubusercontent.com/api-evangelist/justcall/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-05-11'
specificationVersion: '0.23'
apis:
- aid: justcall:rest-api
  name: JustCall REST API
  description: REST API for placing calls, sending SMS and MMS messages, managing contacts, phone numbers, users, and call
    dispositions in JustCall. Authentication uses an API key and API secret passed in the Authorization header. Webhooks notify
    on completed calls and SMS events.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Voice
  - SMS
  - Telephony
  - Contact Center
  - Webhook
  tags_raw:
  - Voice
  - SMS
  - Telephony
  - Contact Center
  - Webhooks
  properties:
  - type: Documentation
    url: https://developer.justcall.io/docs/overview
  - type: APIReference
    url: https://developer.justcall.io/reference
  - type: Send SMS Endpoint
    url: https://developer.justcall.io/reference/texts_new_v21
  - type: Webhooks
    url: https://justcall.io/product/api-and-webhooks/
- aid: justcall:justcall-calls-api
  name: JustCall Calls API
  description: Manage and query voice calls handled through JustCall.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Calls
  properties:
  - type: OpenAPI
    url: openapi/justcall-calls-api-openapi.yml
- aid: justcall:justcall-contacts-api
  name: JustCall Contacts API
  description: Create and manage contacts in the JustCall directory.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Contacts
  properties:
  - type: OpenAPI
    url: openapi/justcall-contacts-api-openapi.yml
- aid: justcall:justcall-sms-api
  name: JustCall SMS API
  description: Send and manage SMS/MMS messages.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - SMS
  properties:
  - type: OpenAPI
    url: openapi/justcall-sms-api-openapi.yml
common:
- type: CapabilityMap
  url: capabilities/justcall-capability-edges.yml
  name: JustCall Business Capability Map
- type: AgenticAccess
  url: agentic-access/justcall-agentic-access.yml
- type: TrustCenter
  url: security/justcall-trust-center.yml
- type: DomainSecurity
  url: security/justcall-domain-security.yml
- type: Authentication
  url: authentication/justcall-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/justcall-io
- type: Website
  url: https://justcall.io
- type: Documentation
  url: https://developer.justcall.io/docs/overview
- type: DeveloperPortal
  url: https://justcall.io/developer-docs/
- type: Pricing
  url: https://justcall.io/pricing
- type: Signup
  url: https://justcall.io/signup
- type: Support
  url: https://help.justcall.io
- type: LlmsText
  url: https://developer.justcall.io/llms.txt
- url: https://justcall.io/blog/
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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