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 18 API contracts indexed on the APIs.io network, including Calls API, Contacts API, SMS API, and 15 more. Tagged areas include Voice, SMS, Cloud Phone, Contact Center, and Telephony.

The JustCall catalog on APIs.io includes 1 Spectral governance ruleset.

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

🌐 Visit website 📡 Profile data on GitHub

39.1/100 thin ▬ flat Agent 33/100 agent ready Front door AI 6/6 dominant Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 published contract 1 MCP Servers

Voice SMSCloud PhoneContact Center Telephony Communications

What this lets a business do 4

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

Application Communications

AE-150

Phone NumbersRCSSMSWhats App

POST /v2.1/rcs/messages/send POST /v2/texts/new GET /v2.1/whatsapp/messages POST /v2.1/whatsapp/messages/send

Customer Service Management

BC-430

CallsUnified Analytics

POST /v2/unified-analytics/calls/incoming/overview

Customer Relationship Management

BC-420

Contacts

POST /v2.1/contacts

Developer Platform & API Ecosystem Management

BC-4270

Webhooks

POST /v2/webhooks GET /v2/webhooks DELETE /v2/webhooks/url/{url_id}

Kin Score

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

Composite quality — 39.1/100 · thin

Contract Quality 9.7 / 19

Developer Ergonomics 6.8 / 15

Access Clarity 4.7 / 15

Operational Transparency 0.8 / 10

Contract Governance 1.2 / 9

Discoverability 5.6 / 8

Regulatory Posture 2.1 / 15

Create-or-Update Ergonomics 2.2 / 10

Agent readiness — 33/100 · 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

Pagination 5 / 5

Distinct Operations 0 / 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):

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)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
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

9 more unmet checks in the Agent Readiness table above.

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

Access Clarity scores 31.6 — up to +13.7 composite points
Contract Quality scores 51.8 — up to +12.1 composite points
Operational Transparency scores 7.9 — up to +12.0 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/justcall/apis.yml: open an issue on github.com/api-evangelist/justcall 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 →

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	54.3	-	-
Zoom App Marketplace and Partner Ecosystem (builders and partners on Zoom)	builds-on	54.3	-	-
Pipedrive Marketplace (CRM integrations from third-party publishers for the SMB sales CRM)	builds-on	54.3	-	-

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.

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 (verified)

OpenAPI

measured — observed by APIs.io (published)

APIs 18

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.

JustCall AI Voice Agents API

The AI Voice Agents API from JustCall — 2 operation(s) for ai voice agents.

JustCall Appointments API

The Appointments API from JustCall — 3 operation(s) for appointments.

JustCall JustCall AI API

The JustCall AI API from JustCall — 13 operation(s) for justcall ai.

JustCall OAuth API

The Oauth API from JustCall — 5 operation(s) for oauth.

JustCall Phone Numbers API

The Phone Numbers API from JustCall — 3 operation(s) for phone numbers.

JustCall RCS API

The RCS API from JustCall — 9 operation(s) for rcs.

JustCall Sales Dialer API

The Sales Dialer API from JustCall — 21 operation(s) for sales dialer.

JustCall Sales Dialer - Phone Numbers API

The Sales Dialer - Phone Numbers API from JustCall — 2 operation(s) for sales dialer - phone numbers.

JustCall Special Dates API

The Special Dates API from JustCall — 2 operation(s) for special dates.

JustCall Unified Analytics API

The Unified Analytics API from JustCall — 62 operation(s) for unified analytics.

JustCall User Groups API

The User Groups API from JustCall — 3 operation(s) for user groups.

JustCall Users API

The Users API from JustCall — 3 operation(s) for users.

JustCall Webhooks API

The Webhooks API from JustCall — 10 operation(s) for webhooks.

JustCall Whats App API

The Whats App API from JustCall — 5 operation(s) for whats app.

Scroll for all 18

Open Collections 4

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

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; 4 tools listed.

MCP SERVER

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

JustCall API Rules

50 rules · 44 errors 5 warnings 1 info

SPECTRAL

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: '2026-11-06'
  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
- aid: justcall:justcall-ai-voice-agents-api
  name: JustCall AI Voice Agents API
  description: The AI Voice Agents API from JustCall — 2 operation(s) for ai voice agents.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - AI Voice Agents
  properties:
  - type: OpenAPI
    url: openapi/justcall-ai-voice-agents-api-openapi.yml
- aid: justcall:justcall-appointments-api
  name: JustCall Appointments API
  description: The Appointments API from JustCall — 3 operation(s) for appointments.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Appointments
  properties:
  - type: OpenAPI
    url: openapi/justcall-appointments-api-openapi.yml
- aid: justcall:justcall-justcall-ai-api
  name: JustCall JustCall AI API
  description: The JustCall AI API from JustCall — 13 operation(s) for justcall ai.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - JustCall AI
  properties:
  - type: OpenAPI
    url: openapi/justcall-justcall-ai-api-openapi.yml
- aid: justcall:justcall-oauth-api
  name: JustCall OAuth API
  description: The Oauth API from JustCall — 5 operation(s) for oauth.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - OAuth
  - Authentication
  tags_raw:
  - Oauth
  - Authentication
  properties:
  - type: OpenAPI
    url: openapi/justcall-oauth-api-openapi.yml
- aid: justcall:justcall-phone-numbers-api
  name: JustCall Phone Numbers API
  description: The Phone Numbers API from JustCall — 3 operation(s) for phone numbers.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Phone Numbers
  properties:
  - type: OpenAPI
    url: openapi/justcall-phone-numbers-api-openapi.yml
- aid: justcall:justcall-rcs-api
  name: JustCall RCS API
  description: The RCS API from JustCall — 9 operation(s) for rcs.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - RCS
  properties:
  - type: OpenAPI
    url: openapi/justcall-rcs-api-openapi.yml
- aid: justcall:justcall-sales-dialer-api
  name: JustCall Sales Dialer API
  description: The Sales Dialer API from JustCall — 21 operation(s) for sales dialer.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Sales Dialer
  properties:
  - type: OpenAPI
    url: openapi/justcall-sales-dialer-api-openapi.yml
- aid: justcall:justcall-sales-dialer-phone-numbers-api
  name: JustCall Sales Dialer - Phone Numbers API
  description: The Sales Dialer - Phone Numbers API from JustCall — 2 operation(s) for sales dialer - phone numbers.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Sales Dialer - Phone Numbers
  properties:
  - type: OpenAPI
    url: openapi/justcall-sales-dialer-phone-numbers-api-openapi.yml
- aid: justcall:justcall-special-dates-api
  name: JustCall Special Dates API
  description: The Special Dates API from JustCall — 2 operation(s) for special dates.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Special Dates
  properties:
  - type: OpenAPI
    url: openapi/justcall-special-dates-api-openapi.yml
- aid: justcall:justcall-unified-analytics-api
  name: JustCall Unified Analytics API
  description: The Unified Analytics API from JustCall — 62 operation(s) for unified analytics.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Unified Analytics
  properties:
  - type: OpenAPI
    url: openapi/justcall-unified-analytics-api-openapi.yml
- aid: justcall:justcall-user-groups-api
  name: JustCall User Groups API
  description: The User Groups API from JustCall — 3 operation(s) for user groups.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - User Groups
  properties:
  - type: OpenAPI
    url: openapi/justcall-user-groups-api-openapi.yml
- aid: justcall:justcall-users-api
  name: JustCall Users API
  description: The Users API from JustCall — 3 operation(s) for users.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - User
  tags_raw:
  - Users
  properties:
  - type: OpenAPI
    url: openapi/justcall-users-api-openapi.yml
- aid: justcall:justcall-webhooks-api
  name: JustCall Webhooks API
  description: The Webhooks API from JustCall — 10 operation(s) for webhooks.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - Webhook
  tags_raw:
  - Webhooks
  properties:
  - type: OpenAPI
    url: openapi/justcall-webhooks-api-openapi.yml
- aid: justcall:justcall-whats-app-api
  name: JustCall Whats App API
  description: The Whats App API from JustCall — 5 operation(s) for whats app.
  humanURL: https://developer.justcall.io/docs/overview
  baseURL: https://api.justcall.io/v2.1
  tags:
  - WhatsApp
  tags_raw:
  - Whats App
  properties:
  - type: OpenAPI
    url: openapi/justcall-whats-app-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

JustCall API — frequently asked questions

Does JustCall have an API?

Yes. APIs.io lists 18 APIs from JustCall, including JustCall REST API, JustCall Calls API and JustCall Contacts API, and 15 more.

Is there an OpenAPI specification for the JustCall API?

Yes. APIs.io indexes 17 OpenAPI specifications for JustCall, each linked for download from this page.

How do I authenticate with the JustCall API?

JustCall uses bearer-token authentication (apiKey · 1 scheme). The details are profiled on APIs.io as Justcall Authentication.

Does JustCall have an MCP server?

Yes. APIs.io lists 1 MCP server for JustCall: Remote MCP server at developer.justcall.io over HTTP; 4 tools listed.

Is the JustCall API ready for AI agents?

JustCall has a Kin Score of 39.1 out of 100 (thin) and an Agent Readiness score of 32.6 (agent-ready), scored by API Evangelist on 2026-11-06.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

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One button, every client — Claude, Cursor, VS Code and the rest.

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find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

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