Speech-to-text transcription

SGL transcription turns one short utterance into final text. The first candidate model is whisper-1, a pinned multilingual Whisper Small model running on a pinned whisper.cpp runtime. Dictation does not interpret the transcript as an instruction, call tools, or press Enter for you.

Release candidate: transcription is default off. The Grid route, model catalogue, discovery, rankings, and provider listing remain unavailable until private canary tests pass and a released capability-qualified node is ready. The desktop Dictation workspace is also unavailable in public builds until its release gates pass. Do not assume whisper-1 is available unless GET /v1/models?type=transcription returns it.

Choose Local or Grid

Mode	Where audio is processed	Network and payment	Availability
Local	On your computer in the managed desktop runtime. Audio and transcript stay on the device.	No wallet, internet, credits, or Grid provider is required after the verified model is installed.	The default dictation mode. It remains release-gated until signed macOS and real Windows runtime tests pass.
Grid	On a selected capability-qualified provider node. The client seals audio to that node before the Grid receives the request.	Requires explicit selection plus prepaid credits or an x402 payment. The app shows the quote before the first paid request.	Available only when public feature gates are on and discovery returns a ready provider for `whisper-1`. There is no automatic fallback from Local to Grid.

Local and Grid share the final transcription-v1 result contract. Local inference does not use the Grid API. Grid availability does not imply that a local Voice Engine is installed, and local model availability does not imply that the same engine is served on Grid.

Grid request flow

Grid transcription uses two JSON requests:

POST /v1/audio/transcriptions/reserve sends metadata only: the model, protocol, language hint, request identity, exact model_revision and model_sha256 pins, and PCM sample count. A successful response identifies a ready node, returns its verified encryption and signing keys, and quotes the maximum price.
The client validates the reservation, seals the bounded PCM bytes to that node, and sends the reservation token plus encrypted envelope to POST /v1/audio/transcriptions.
The client verifies the node signature over the sealed result before decrypting it. It then checks the request, model, immutable revision, sample count, duration, language, segment order, and quote binding before returning text.

The wire format is client-sealed JSON. It is not OpenAI multipart form data, and there is no plain-audio or legacy fallback. Use the TypeScript or Python SDK helper so reservation binding, key verification, sealing, signature verification, and result validation stay consistent.

The familiar final fields such as text, language, duration_seconds, and segments do not make the request OpenAI wire-compatible. Sending multipart/form-data, a filename, URL, WAV, MP3, or FLAC directly to this endpoint is rejected.

TypeScript SDK

Read or capture raw PCM bytes, then pass them to the bounded helper:

import { readFile } from "node:fs/promises";
import { GridClient } from "@singularity-layer/grid";

const grid = new GridClient({ apiKey: process.env.SGL_API_KEY! });
const pcm = new Uint8Array(await readFile("utterance.pcm"));

const result = await grid.transcribePcm(pcm, {
  model: "whisper-1",
  language: "auto",
  useCredits: true,
});

console.log(result.text);
console.log(result.usage?.cost_usd);

In a browser, transcribePcmFile(file) accepts a Blob whose bytes are already raw PCM. It does not decode a WAV or compressed audio container.

Python SDK

import os
from singularity_grid import GridClient

grid = GridClient(api_key=os.environ["SGL_API_KEY"])
result = grid.transcribe_pcm_file(
    "utterance.pcm",
    model="whisper-1",
    language="auto",
    use_credits=True,
)

print(result["text"])
print(result.get("usage", {}).get("cost_usd"))

Use transcribe_pcm(pcm_bytes, ...) when audio is already in memory. Both SDKs reject empty, odd-length, oversized, or incorrectly configured input before reserving a node or sending audio.

Audio contract and limits

Convert audio on the client before reservation:

Property	Required value
Encoding	Raw signed 16-bit little-endian PCM
Sample rate	16,000 Hz
Channels	1 (mono)
Utterances	One per request
PCM samples	1-960,000
Decoded PCM bytes	2-1,920,000, always an even count
Duration	At most 60 seconds
Reserve metadata body	At most 16 KiB
Encoded submit body	At most 8 MiB
Final transcript	At most 64 KiB UTF-8
Segments	At most 256, ordered with monotonic timestamps

The sample count is the duration and billing authority. The reserve request never trusts a filename, MIME type, container duration, or caller-supplied seconds. The encrypted envelope binds the same sample count, and the node checks the decrypted byte length again. Longer dictation sessions must be split into separate bounded utterances on the client. v1 does not provide live word streaming, diarization, translation, speaker identity, or word-level timestamps. A desktop preview, when shown, is provisional; only the validated final transcript is eligible for insertion.

Language hints

Use auto to let the model detect the language, or pass a lowercase two-letter language hint such as en, fr, or de. A hint narrows transcription behavior; it does not request translation. The final language field can be null when the runtime cannot provide a validated detected language.

Pricing and payment

The candidate price is $0.0001 per exact audio second**, equal to **$0.006 per minute. The minimum charge is $0.0001**. A 4.2-second utterance costs **$0.000420. Compute the charge in integer micro-USDC: max(100, ceil(sample_count × 100 / 16000)) / 1000000. Only the charge rounds up to the next micro-USDC; audio duration never rounds to whole seconds. The quote derives from the authenticated PCM sample count. The Grid does not use node-reported duration for billing. A successful request is charged at most once after the final transcript and node signature validate. Invalid audio, unavailable nodes, terminal timeouts, and invalid node results are not billed. Cancellation before submit sends no audio and incurs no charge. If submit has already started, cancellation or a lost response does not prove a no-charge outcome; reconcile the job first. There is no transparent server failover: after a confirmed terminal failure with no charge, create a new reservation and seal the PCM again to the new node. SDKs do not automatically retry a submit with an ambiguous result or payment outcome. Never blindly resubmit an x402 request whose result says billing is pending or its settlement outcome is unknown; reconcile the returned job/payment identity first. Use an X-API-Key with grid:write for prepaid credits. Set use_credits=false for the direct x402 contract: reservation returns the quote and submit returns the payment challenge. The TypeScript and Python transcription helpers currently use prepaid credits and do not sign x402 payments. A missing key with use_credits=true requires a valid session or returns 401. Do not attach an audio file to a generic x402 client.

Privacy and retention

The client seals PCM to the reserved node before sending the submit request. The selected provider decrypts the audio to run inference; encryption does not hide audio from that provider. The orchestrator receives only the reservation metadata and encrypted envelope. It has no plaintext fallback and must not log or persist raw audio or transcripts. The handler clears encrypted input and result on terminal response paths. The hourly purge is a backup for residual or abandoned payloads: terminal input becomes eligible after 30 minutes and result after one hour. Under a healthy hourly scheduler, expected cleanup is about 90 minutes for residual input and two hours for results. These are expected cleanup windows, not guaranteed maximum retention; scheduler failures can delay removal. Accounting keeps only bounded metadata such as model, duration, price, node, and status. Local mode keeps audio and transcripts in memory by default. It does not upload them or create a local transcript history. Treat every transcript as untrusted text. Render it as text, do not interpret it as markup or a tool instruction, and never submit it as a terminal command. The desktop app rechecks the original editable, nonsecure target before insertion. If focus changed or the target cannot be proved safe, it leaves existing text untouched and offers Copy.

Discover availability

curl "https://grid.x402compute.cc/v1/models?type=transcription"
curl "https://grid.x402compute.cc/v1/providers?model=whisper-1"

An empty model list or a missing whisper-1 means public Grid transcription is unavailable. A catalogue row alone is not enough. The route requires literal public feature gates and at least one active node with the exact model/runtime revisions, transcription-v1, 16 kHz PCM capability, current verified encryption-key binding, available slot, and a successful real-audio startup smoke. The release controls are independent: STT_ENABLED=true admits only the guarded route, STT_PUBLIC=true permits public discovery and routing, and the whisper-1 catalogue row must have both enabled and transcription_enabled set after canary approval. Private canaries additionally require an exact secret and explicit node allowlist. All controls default off; setting one does not implicitly set another.

Candidate pins

These pins describe the candidate under test. They do not announce a public release:

Component	Immutable candidate
Model id	`whisper-1`
Model	Whisper Small multilingual, `ggml-small.bin`
Model revision	Hugging Face commit `5359861c739e955e79d9a303bcbc70fb988958b1`
Model SHA-256	`1be3a9b2063867b937e64e2ec7483364a79917e157fa98c5d94b5c1fffea987b`
Model size	487,601,967 bytes
Model license	Apache-2.0
Grid runtime	whisper.cpp v1.9.5, commit `d1be6fde11ac6e0407606b4e42fe72d34add8037`
Runtime license	MIT
Protocol	`transcription-v1`

Other local speech engines are not supported or advertised by this candidate. The candidate has not completed the quality bake-off, packaged runtime, or supported-platform release tests; pins and license labels alone do not prove release readiness. A future Voice Engine catalogue must pass its own immutable-pin, license, platform, quality, and packaging gates before it appears. See Reserve a transcription node and Submit a sealed transcription for the wire reference.

Overview

User Guide

Slayer Agent

Core flows

Staking Engine

Singularity Cloud Network

Contract Addresses

ERC8004

Skills

Singularity Payments

Agentic Fundraisers

Enterprise

Choose Local or Grid

Grid request flow

TypeScript SDK

Python SDK

Audio contract and limits

Language hints

Pricing and payment

Privacy and retention

Discover availability

Candidate pins

​Choose Local or Grid

​Grid request flow

​TypeScript SDK

​Python SDK

​Audio contract and limits

​Language hints

​Pricing and payment

​Privacy and retention

​Discover availability

​Candidate pins

Choose Local or Grid

Grid request flow

TypeScript SDK

Python SDK

Audio contract and limits

Language hints

Pricing and payment

Privacy and retention

Discover availability

Candidate pins