Synthflow

Synthflow is an enterprise-ready no-code Voice AI platform for automating phone conversations at scale. The product combines a visual agent designer with in-house telephony, sub-100ms latency, and a 99.99% uptime guarantee, so businesses can build, deploy, and operate voice agents without third-party carriers. Synthflow exposes a REST Platform API for assistants, calls, phone numbers, knowledge bases, and custom actions, with bearer token authentication. The platform claims more than 200 integrations including HubSpot, Salesforce, Cal.com, Zapier, and CCaaS systems, plus custom webhook actions. Compliance covers SOC 2, HIPAA, PCI DSS, and GDPR with end-to-end encryption and audit logging.

Synthflow publishes 7 APIs on the APIs.io network, including Default API, Chat API, Contacts API, and 4 more. Tagged areas include Voice, Voice Agents, No-Code, Telephony, and Phone.

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

Synthflow’s developer surface includes authentication, documentation, engineering blog, pricing, API reference, getting-started guide, support, and 34 more developer resources.

🌐 Visit website 📡 Source on GitHub

58.9/100 strong ▬ flat Agent 37/100 agent ready saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessEnterprise

1 APIs 2 MCP Servers

Voice Voice Agents No-Code Telephony Phone Outbound Inbound CRM Webhook Custom Actions HIPAA SOC 2 MCP Agent Skills Conversational AI SIP Simulations Knowledge Base

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 58.9/100 · strong

Contract Quality 14.0 / 23

Developer Ergonomics 12.9 / 18

Access Clarity 10.0 / 18

Operational Transparency 8.0 / 12

Contract Governance 2.0 / 11

Discoverability 6.8 / 9

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 37/100 · 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 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

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.

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/synthflow: 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 8

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

Synthflow Platform API

The Synthflow Platform API provides REST endpoints to manage assistants, phone numbers, calls, knowledge bases, and custom actions for no-code voice AI agents. Authentication is...

Synthflow Default API

The Default API from Synthflow — 49 operation(s) for default.

Synthflow Chat API

The chat API from Synthflow — 4 operation(s) for chat.

Synthflow Contacts API

The contacts API from Synthflow — 2 operation(s) for contacts.

Synthflow MCP API

The mcp API from Synthflow — 3 operation(s) for mcp.

Synthflow Memory Stores API

The memoryStores API from Synthflow — 1 operation(s) for memorystores.

Synthflow Phone Numbers API

The phoneNumbers API from Synthflow — 3 operation(s) for phonenumbers.

Synthflow Webhook Logs API

The webhookLogs API from Synthflow — 2 operation(s) for webhooklogs.

Scroll for all 8

Open Collections 9

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

API Collection

OPEN COLLECTION

Platform API

OPEN COLLECTION

Platform subpackage_chat API

OPEN COLLECTION

Platform subpackage_contacts API

OPEN COLLECTION

Platform subpackage_mcp API

OPEN COLLECTION

Platform subpackage_memoryStores API

OPEN COLLECTION

Platform subpackage_phoneNumbers API

OPEN COLLECTION

Platform subpackage_webhookLogs API

OPEN COLLECTION

Platform API

OPEN COLLECTION

Scroll for all 9

MCP Servers 2

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

Synthflow MCP Server

MCP SERVER

Synthflow MCP Server

Synthflow publishes a first-party hosted MCP server that lets an MCP client (Claude, Claude Code, ChatGPT, Codex, Cursor) manage a Synthflow workspace — agents, calls, actions, ...

MCP SERVER

Pricing Plans 1

Published pricing tiers and plan structures.

Synthflow Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Synthflow Rate Limits

2 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Synthflow Finops

FINOPS

Event Specifications 1

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

Synthflow Webhooks

ASYNCAPI

Security Posture 3

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

Synthflow Authentication

http/oauth2 · 3 schemes

SECURITY

Synthflow Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Synthflow Trust Center

ISO 27001:2022, SOC 2, GDPR, HIPAA, PCI DSS v4.0.1

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Synthflow Scopes

4 scopes · authorizationCode/deviceCode/refreshToken

4 scopes

SCOPES

Agentic Access 1

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

Synthflow Agentic Access

98 operations · 61 acting

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

SignUp

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 6

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

LlmsText

LLMsTxt

MCPServer

AgentSkill

WellKnown

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Webhooks

ErrorCatalog

Conventions

Lifecycle

Conformance

DataModel

Components

Scroll for all 7

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

ToolCrosswalk

ToolCrosswalk

Packages

Packages

Access & Security 5

Authentication, authorization, and security posture

DomainSecurity

Authentication

Compliance

TrustCenter

OAuthScopes

Operate 5

Status, limits, changes, and where to get help

Roadmap

Support

StatusPage

ChangeLog

RateLimits

Commercial 4

Pricing, plans, and the legal terms of use

Pricing

TermsOfService

PrivacyPolicy

Plans

Company 3

The organization behind the API

Website

Website

Blog

Blog

LinkedIn

Other 2

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: synthflow
name: Synthflow
description: Synthflow is an enterprise-ready no-code Voice AI platform for automating phone conversations at scale. The product
  combines a visual agent designer with in-house telephony, sub-100ms latency, and a 99.99% uptime guarantee, so businesses
  can build, deploy, and operate voice agents without third-party carriers. Synthflow exposes a REST Platform API for assistants,
  calls, phone numbers, knowledge bases, and custom actions, with bearer token authentication. The platform claims more than
  200 integrations including HubSpot, Salesforce, Cal.com, Zapier, and CCaaS systems, plus custom webhook actions. Compliance
  covers SOC 2, HIPAA, PCI DSS, and GDPR with end-to-end encryption and audit logging.
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: enterprise
  onboarding: sales
  trial: false
  try_now: false
  public: false
  label: Enterprise · Contact sales
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-08-13'
  method: searched
  note: Corrected 2026-08-13. https://synthflow.ai/pricing publishes a single Enterprise tier starting at $30,000 annually
    with a Contact Sales call to action; the earlier self-serve/free reading came from a scaffolded plans file. Synthflow's
    own concurrency docs confirm the former Pro, Growth and Agency self-serve plans are retired and closed to new subscriptions.
position: Producing
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/synthflow.png
tags:
- Voice
- Voice Agents
- No-Code
- Telephony
- Phone
- Outbound
- Inbound
- CRM
- Webhook
- Custom Actions
- HIPAA
- SOC 2
- MCP
- Agent Skills
- Conversational AI
- SIP
- Simulations
- Knowledge Base
tags_raw:
- Voice
- Voice Agents
- No-Code
- Telephony
- Phone
- Outbound
- Inbound
- CRM
- Webhooks
- Custom Actions
- HIPAA
- SOC 2
- MCP
- Agent Skills
- Conversational AI
- SIP
- Simulations
- Knowledge Base
url: https://raw.githubusercontent.com/api-evangelist/synthflow/refs/heads/main/apis.yml
created: '2026-05-23'
modified: '2026-08-13'
specificationVersion: '0.23'
apis:
- aid: synthflow:platform-api
  name: Synthflow Platform API
  description: The Synthflow Platform API provides REST endpoints to manage assistants, phone numbers, calls, knowledge bases,
    and custom actions for no-code voice AI agents. Authentication is via bearer tokens and the API is available in multiple
    regions.
  humanURL: https://docs.synthflow.ai
  baseURL: https://api.synthflow.ai
  tags:
  - Assistants
  - Calls
  - Phone Numbers
  - Knowledge Bases
  - Actions
  - REST
  properties:
  - type: Documentation
    url: https://docs.synthflow.ai
  - type: GettingStarted
    url: https://docs.synthflow.ai/getting-started-with-your-api
  - type: Signup
    url: https://app.synthflow.ai
  - type: APIReference
    url: https://docs.synthflow.ai/api-reference/platform-api
  - type: MCPServer
    url: https://mcp.synthflow.ai/mcp
  - type: RateLimits
    url: https://docs.synthflow.ai/concurrency-calling-limits
  - type: Pricing
    url: https://synthflow.ai/pricing
  - type: Authentication
    url: https://docs.synthflow.ai/getting-started-with-your-api
  features:
  - name: Assistants Management
    description: Create, configure, and manage AI voice assistants via API.
  - name: Inbound and Outbound Calls
    description: Manage inbound call routing and trigger outbound calls programmatically.
  - name: Phone Number Provisioning
    description: Provision and manage phone numbers across regions.
  - name: Knowledge Bases
    description: Create knowledge bases that ground agent responses in your content.
  - name: Custom Actions
    description: Define webhook-based custom actions that agents can call during conversations.
  - name: In-House Telephony
    description: Native telephony stack with sub-100ms latency and 99.99% uptime.
  - name: Multi-Region Deployment
    description: Deploy assistants in the region that fits your workload and compliance needs.
  - name: Compliance
    description: SOC 2, HIPAA, PCI DSS, and GDPR with end-to-end encryption and audit logs.
  useCases:
  - name: Inbound Call Automation
    description: Automate inbound support, reception, and qualification calls.
  - name: Outbound Campaigns
    description: Run outbound calling campaigns for sales, surveys, and reminders.
  - name: Appointment Setting
    description: Book and confirm appointments with calendar integrations.
  - name: Lead Qualification
    description: Qualify and route leads to sales reps with CRM updates.
  - name: Healthcare Workflows
    description: Run HIPAA-aligned voice workflows for patient outreach and intake.
  integrations:
  - name: HubSpot
  - name: Salesforce
  - name: Cal.com
  - name: Calendly
  - name: Zapier
  - name: Make
  - name: Twilio
  - name: Google Sheets
  - name: Slack
  - name: Webhooks
  - name: OpenAI
  - name: Anthropic
  - name: ElevenLabs
  - name: Cartesia
  - name: Deepgram
  authentication:
  - type: API Key
    description: HTTP Bearer authentication using an API key generated in the Synthflow dashboard.
- aid: synthflow:synthflow-default-api
  name: Synthflow Default API
  description: The Default API from Synthflow — 49 operation(s) for default.
  humanURL: https://docs.synthflow.ai
  baseURL: https://api.synthflow.ai
  tags: []
  tags_raw:
  - Default
  properties:
  - type: OpenAPI
    url: openapi/synthflow-default-api-openapi.yml
- aid: synthflow:synthflow-chat-api
  name: Synthflow Chat API
  description: The chat API from Synthflow — 4 operation(s) for chat.
  humanURL: https://docs.synthflow.ai
  baseURL: https://api.synthflow.ai
  tags:
  - Chat
  tags_raw:
  - chat
  properties:
  - type: OpenAPI
    url: openapi/synthflow-chat-api-openapi.yml
- aid: synthflow:synthflow-contacts-api
  name: Synthflow Contacts API
  description: The contacts API from Synthflow — 2 operation(s) for contacts.
  humanURL: https://docs.synthflow.ai
  baseURL: https://api.synthflow.ai
  tags:
  - Contacts
  tags_raw:
  - contacts
  properties:
  - type: OpenAPI
    url: openapi/synthflow-contacts-api-openapi.yml
- aid: synthflow:synthflow-mcp-api
  name: Synthflow MCP API
  description: The mcp API from Synthflow — 3 operation(s) for mcp.
  humanURL: https://docs.synthflow.ai
  baseURL: https://api.synthflow.ai
  tags:
  - MCP
  tags_raw:
  - mcp
  properties:
  - type: OpenAPI
    url: openapi/synthflow-mcp-api-openapi.yml
- aid: synthflow:synthflow-memorystores-api
  name: Synthflow Memory Stores API
  description: The memoryStores API from Synthflow — 1 operation(s) for memorystores.
  humanURL: https://docs.synthflow.ai
  baseURL: https://api.synthflow.ai
  tags:
  - Memory Stores
  tags_raw:
  - memoryStores
  properties:
  - type: OpenAPI
    url: openapi/synthflow-memorystores-api-openapi.yml
- aid: synthflow:synthflow-phonenumbers-api
  name: Synthflow Phone Numbers API
  description: The phoneNumbers API from Synthflow — 3 operation(s) for phonenumbers.
  humanURL: https://docs.synthflow.ai
  baseURL: https://api.synthflow.ai
  tags:
  - Phone Numbers
  tags_raw:
  - phoneNumbers
  properties:
  - type: OpenAPI
    url: openapi/synthflow-phonenumbers-api-openapi.yml
- aid: synthflow:synthflow-webhooklogs-api
  name: Synthflow Webhook Logs API
  description: The webhookLogs API from Synthflow — 2 operation(s) for webhooklogs.
  humanURL: https://docs.synthflow.ai
  baseURL: https://api.synthflow.ai
  tags:
  - Webhook Logs
  tags_raw:
  - webhookLogs
  properties:
  - type: OpenAPI
    url: openapi/synthflow-webhooklogs-api-openapi.yml
common:
- type: AgenticAccess
  url: agentic-access/synthflow-agentic-access.yml
- type: DomainSecurity
  url: security/synthflow-domain-security.yml
- type: Authentication
  url: authentication/synthflow-authentication.yml
- type: Website
  url: https://synthflow.ai
- type: Documentation
  url: https://docs.synthflow.ai
- type: Blog
  url: https://synthflow.ai/blog
- type: Pricing
  url: https://synthflow.ai/pricing
- type: TermsOfService
  url: https://synthflow.ai/terms-of-service
- type: PrivacyPolicy
  url: https://synthflow.ai/privacy-policy
- type: X
  url: https://x.com/synthflowai
- type: LinkedIn
  url: https://www.linkedin.com/company/synthflowai
- type: LlmsText
  url: https://docs.synthflow.ai/llms.txt
- type: LLMsTxt
  url: llms/synthflow-llms.txt
- type: DeveloperPortal
  url: https://docs.synthflow.ai
- type: APIReference
  url: https://docs.synthflow.ai/api-reference/platform-api
- type: GettingStarted
  url: https://docs.synthflow.ai/getting-started
- type: GitHubOrganization
  url: https://github.com/SynthFlowAI
- type: Roadmap
  url: https://feedback.synthflow.ai/roadmap
- type: Support
  url: mailto:support@synthflow.ai
- type: SignUp
  url: https://app.synthflow.ai
- type: StatusPage
  url: https://status.synthflow.ai/
- type: Compliance
  url: https://security.synthflow.ai/
- type: TrustCenter
  url: security/synthflow-trust-center.yml
- type: MCPServer
  url: mcp/synthflow-mcp.yml
- type: ToolCrosswalk
  url: mcp/synthflow-tool-crosswalk.yml
- type: AgentSkill
  url: skills/_index.yml
- type: WellKnown
  url: well-known/synthflow-well-known.yml
- type: Packages
  url: packages/synthflow-packages.yml
- type: Webhooks
  url: asyncapi/synthflow-webhooks.yml
- type: ErrorCatalog
  url: errors/synthflow-problem-types.yml
- type: Conventions
  url: conventions/synthflow-conventions.yml
- type: Lifecycle
  url: lifecycle/synthflow-lifecycle.yml
- type: ChangeLog
  url: changelog/synthflow-changelog.yml
- type: Conformance
  url: conformance/synthflow-conformance.yml
- type: OAuthScopes
  url: scopes/synthflow-scopes.yml
- type: Sandbox
  url: sandbox/synthflow-sandbox.yml
- type: DataModel
  url: data-model/synthflow-data-model.yml
- type: Components
  url: components/synthflow-components.yml
- type: Overlay
  url: overlays/synthflow-default-api-overlay.yaml
- type: Plans
  url: plans/synthflow-plans-pricing.yml
- type: RateLimits
  url: rate-limits/synthflow-rate-limits.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 34
  pass: local-v1

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