Modulate
Modulate is a voice AI company based in Cambridge, Massachusetts, building audio-native voice intelligence for trust, safety, and conversation understanding. Its Velma-2 platform exposes a suite of REST (batch) and WebSocket (streaming) model APIs — multilingual and English speech-to-text transcription with speaker diarization, deepfake (synthetic voice) detection, emotion and accent detection, PII/PHI tagging and redaction, language detection, and music/speech and AI-music detection — alongside Velma conversation analysis (behaviors, topics, sentiment, participant roles) and the ToxMod voice-safety product for gaming and social platforms. Authentication is via an X-API-Key header (an api_key query parameter for WebSocket streams), billed per hour of audio processed. Backed by Sierra Ventures.
Solid contracts, transparent operations, and an easy start — typically complete on four or five facets with one clear soft spot.
API Evangelist profiles Modulate the way a machine reads it — 34 machine-readable artifacts across 11 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Modulate scores 55.7/100 (strong), with a separate agent-readiness read of 31/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-08 · rubric v0.20.0
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How we profile Modulate
Each block below is one kind of artifact we hold for Modulate. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 11
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
Modulate Velma 2 Accent Batch API
The Velma 2 Accent Batch API from Modulate — 1 operation(s) for velma 2 accent batch.
Modulate Velma 2 Ai Music Detection Batch API
The Velma 2 Ai Music Detection Batch API from Modulate — 1 operation(s) for velma 2 ai music detection batch.
Modulate Velma 2 Batch API
The Velma 2 Batch API from Modulate — 2 operation(s) for velma 2 batch.
Modulate Velma 2 Emotion Batch API
The Velma 2 Emotion Batch API from Modulate — 1 operation(s) for velma 2 emotion batch.
Modulate Velma 2 Language Detection Batch API
The Velma 2 Language Detection Batch API from Modulate — 1 operation(s) for velma 2 language detection batch.
Modulate Velma 2 Music Detection Batch API
The Velma 2 Music Detection Batch API from Modulate — 1 operation(s) for velma 2 music detection batch.
Modulate Velma 2 Pii Phi Redaction Batch API
The Velma 2 Pii Phi Redaction Batch API from Modulate — 1 operation(s) for velma 2 pii phi redaction batch.
Modulate Velma 2 Stt Batch API
The Velma 2 Stt Batch API from Modulate — 1 operation(s) for velma 2 stt batch.
Modulate Velma 2 Stt Batch English Vfast API
The Velma 2 Stt Batch English Vfast API from Modulate — 1 operation(s) for velma 2 stt batch english vfast.
Modulate Velma 2 Stt Batch Multilingual Vfast API
The Velma 2 Stt Batch Multilingual Vfast API from Modulate — 1 operation(s) for velma 2 stt batch multilingual vfast.
Modulate Velma 2 Synthetic Voice Detection Batch API
The Velma 2 Synthetic Voice Detection Batch API from Modulate — 1 operation(s) for velma 2 synthetic voice detection batch.
Scroll within the panel for all 11 ·
Open Collections 12
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
API Collection
OPEN COLLECTIONVelma 2 Accent Batch API
OPEN COLLECTIONVelma 2 Accent Batch Velma 2 Ai Music Detection Batch API
OPEN COLLECTIONVelma 2 Accent Batch Velma 2 Batch API
OPEN COLLECTIONVelma 2 Accent Batch Velma 2 Emotion Batch API
OPEN COLLECTIONVelma 2 Accent Batch Velma 2 Language Detection Batch API
OPEN COLLECTIONVelma 2 Accent Batch Velma 2 Music Detection Batch API
OPEN COLLECTIONVelma 2 Accent Batch Velma 2 Pii Phi Redaction Batch API
OPEN COLLECTIONVelma 2 Accent Batch Velma 2 Stt Batch API
OPEN COLLECTIONVelma 2 Accent Batch Velma 2 Stt Batch English Vfast API
OPEN COLLECTIONScroll within the panel for all 12 ·
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Modulate Rate Limits
RATE LIMITSEvent Specifications 7
Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Velma 2 AI Music Detection Streaming API
Real-time AI music detection over WebSocket. The client streams audio and receives per-window vocal AI verdicts as they become available, followed by a final clip-level summary ...
ASYNCAPIVelma 2 Music Detection Streaming API
Real-time frame-level music and speech classification over WebSocket. The client streams audio and receives per-frame probabilities as they become available, followed by a final...
ASYNCAPIVelma 2 PII/PHI Redaction Streaming API
Real-time speech-to-text with PII/PHI redaction over WebSocket. Provides live transcription with automatic language detection, PII/PHI detection and text redaction, and a redact...
ASYNCAPIVelma 2 STT Streaming API
Real-time speech-to-text over WebSocket. Provides live multilingual transcription with automatic per-utterance language detection, delivering each utterance as it is completed. ...
ASYNCAPIVelma 2 STT Streaming English v2 API
Low-latency English speech-to-text over WebSocket. Pure transcription only - no diarization, emotion detection, accent detection, or PII/PHI tagging. Streams interim partial tra...
ASYNCAPIVelma 2 Synthetic Voice Detection Streaming API
Real-time synthetic voice detection for single-speaker audio over WebSocket. The client streams audio and receives per-frame verdicts as they become available.
ASYNCAPIModulate Velma-2 Streaming Server
Streaming velma-2 over WebSocket. Transcribes and analyzes a live audio stream against a client-supplied analysis configuration, emitting JSON events that describe clips and ana...
ASYNCAPIScroll within the panel for all 7 ·
Security Posture 3
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Resources
Every other property we hold for Modulate — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 5
Portal, sign-up, and the first successful call
Documentation 3
Reference material describing how the API behaves
Agent Surfaces 3
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 5
Pagination, idempotency, versioning, errors, and events
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 4
Authentication, authorization, and security posture
Operate 2
Status, limits, changes, and where to get help
Commercial 3
Pricing, plans, and the legal terms of use
Company 2
The organization behind the API
Other 1
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/modulate · machine-readable index on apis.io
This is an independent, third-party profile of Modulate, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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