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Kensho Scribe Real Time API

Real-time streaming transcription over a WebSocket at wss://scribe.kensho.com/ws. Clients send an Authenticate message with a Kensho OIDC access token, then StartTranscription with an audio_format (RAW pcm_s16le, 16 kHz, mono), followed by base64-encoded AddData chunks of at most 15 seconds each carrying monotonically increasing sequence_numbers, and finally EndOfStream. The server streams TranscriptionStarted, DataAdded, AddTranscript, EndOfTranscript, and Error messages back over the same socket. This is the only public WebSocket surface S&P Global exposes — Capital IQ Pro, Marketplace, and other market-data feeds are delivered via REST, file/SFTP, Snowflake share, and Databricks share.

Kensho Scribe Real Time API is one of 9 APIs that S&P Global publishes on the APIs.io network, described by an AsyncAPI event-driven specification.

Tagged areas include Speech to Text, Transcription, WebSocket, Streaming, and Real Time. The published artifact set on APIs.io includes an AsyncAPI specification, API documentation, an API reference, authentication docs, and a JSON-LD context.

This event API exposes 2 operations across 1 channel, and defines 21 schemas. It is described by AsyncAPI 2.6.0, at version 2.0.0.

The API connects through a single server, scribe.kensho.com/ws (wss).

2 operations 1 channels 21 schemas

Metadata

The identity and technical contract details declared by the specification.

Specification
AsyncAPI 2.6.0
API Version
2.0.0
Base URL
wss://scribe.kensho.com/ws
Resource Areas
1

Channels & Operations 2

Across 1 channel, the API surfaces 2 operations. Each is listed below with its action, channel, parameters, and response codes.

Channels 2
SUB
/
Messages sent from Kensho Scribe Real Time to client
receiveServerMessage body
PUB
/
Messages sent from client to Kensho Scribe Real Time
sendClientMessage body

Messages & Schemas 21

The contract defines 21 schemas that model the data carried by its messages. The most detailed are AudioFormat (4 properties), AddDataPayload (3 properties), EndOfStreamPayload (2 properties), AddTranscriptPayload (2 properties). Each schema is shown below with its type and property counts.

Authenticate
message
First client message; supplies the Kensho access token.
Authenticated
message
Server acknowledgement that the access token was accepted.
StartTranscription
message
Configures the audio format and opens a transcription session.
TranscriptionStarted
message
Server confirmation that a transcription session is active.
AddData
message
Sends one chunk of base64-encoded PCM audio. Chunks must represent at most 15 seconds of audio and carry a monotonically increasing sequencenumber.
DataAdded
message
Server acknowledgement that an audio chunk was accepted.
AddTranscript
message
Server-pushed transcript segment for previously sent audio.
EndOfStream
message
Client signal that no further audio will be sent.
EndOfTranscript
message
Server signal that all transcripts for the stream have been emitted.
Error
message
Server error response carrying a human-readable reason.
AudioFormat
object
Audio format descriptor sent in StartTranscription. The publicly documented configuration is RAW PCM signed 16-bit little-endian at 16 kHz mono.
4 properties 4 required
AuthenticatePayload
object
2 properties 2 required
AuthenticatedPayload
object
1 property 1 required
StartTranscriptionPayload
object
2 properties 2 required
TranscriptionStartedPayload
object
2 properties 1 required
AddDataPayload
object
3 properties 3 required
DataAddedPayload
object
2 properties 1 required
AddTranscriptPayload
object
2 properties 2 required
EndOfStreamPayload
object
2 properties 2 required
EndOfTranscriptPayload
object
1 property 1 required
ErrorPayload
object
2 properties 2 required

Specification

The full machine-readable AsyncAPI contract behind this narrative.

Source

kensho-scribe-realtime-asyncapi.yml Raw ↑

Other APIs S&P Global publishes across the network.

S&P Global LLM-Ready API (kFinance)
Kensho Extract API
Kensho NERD API
Kensho Scribe Batch API v2
Kensho Scribe Batch API v1
Kensho Grounding Agent (Alpha)
S&P Capital IQ Pro
S&P Global Marketplace