Sandchest docs — Sandchest

Sandchest turns audio into words. Every word comes back with its own start and end in milliseconds, its own confidence score, and the identifier of the model that actually produced it. This page tells you which door to walk through; the rest of the docs are linear, imperative and end with something you can check.

What it is#

A speech-to-text API you can read the source of. Two HTTP surfaces sit on the same engine: an AssemblyAI-compatible one at /v2/*, and a native one at /api/v1/*. The hosted service runs at https://stt-api.sandchest.com; the same code runs on your own GPU or Apple Silicon machine.


Base URL	`https://stt-api.sandchest.com`
Auth	`Authorization: <your key>` (a `Bearer` prefix also works)
Dashboard	sandchest.com/dashboard
Source	CapSoftware/Sandchest
Machine-readable	`/llms.txt` · `/llms-full.txt` · `/openapi.json`

Three ways in#

Keep the AssemblyAI SDK you already have. Change apiKey and baseUrl, change nothing else. Upload, create, poll, list, delete, sentences, paragraphs, word search, SRT and VTT all work. See Using the AssemblyAI SDK.

transcribe.ts

import { AssemblyAI } from "assemblyai";

const client = new AssemblyAI({
  apiKey: process.env.SANDCHEST_API_KEY,
  baseUrl: "https://stt-api.sandchest.com",
});

Use the native SDK. @sandchest/sdk is small, fully typed, and cancels through uploads, requests and polling. See TypeScript SDK.

transcribe.ts

import { Sandchest } from "@sandchest/sdk";

const client = new Sandchest({ apiKey: process.env.SANDCHEST_API_KEY });

Call the HTTP API directly. Ten endpoints, { "error": "..." } on failure, no client library required. See the API reference.

shell

curl https://stt-api.sandchest.com/v2/transcript/$ID \
  -H "Authorization: $SANDCHEST_API_KEY"

Give this to your agent#

These docs are written to be handed to an AI coding agent. Paste this prompt into Claude Code, Cursor, Codex or anything else that can fetch a URL:

text

Add Sandchest speech-to-text to this project.
Docs: https://sandchest.com/llms.txt (index) — fetch https://sandchest.com/llms-full.txt for everything.
API key: read it from the SANDCHEST_API_KEY environment variable (never hardcode it).
Base URL: https://stt-api.sandchest.com
Use the official assemblyai package if it is already installed (change apiKey + baseUrl), otherwise @sandchest/sdk.
Transcribe <file>, print each word with its start/end in milliseconds, and add a small test.

Every page here is also served as plain Markdown at /docs/<slug>.md, and answers to Accept: text/markdown. Set up with an AI agent has the details and a snippet for your CLAUDE.md or AGENTS.md.

Everything else#

Page	What it covers
Quickstart	Key, environment variable, first transcript, three ways
Set up with an AI agent	The agent prompt, `llms.txt`, raw Markdown, editor rules
Authentication	Keys, header forms, workspaces and roles, rotation
Using the AssemblyAI SDK	The two-line swap, what is supported, what is rejected
Transcript options	Every request field, the transcript object, the word object
Languages	Detection, explicit codes, the supported list, models
Webhooks	Payload, auth header, retries, local testing
API reference	Every endpoint, request, response and error
TypeScript SDK	`@sandchest/sdk` in full
Errors and limits	Status codes, size limits, rate limits, deadlines
Billing	Prepaid credits, per-second metering, top-ups
Self-hosting	Apple Silicon, Docker Compose, required environment

Verify#

You are ready to start when this prints your workspace's ten most recent transcripts (an empty list is a pass — it means the key authenticated):

shell

curl -sS "https://stt-api.sandchest.com/v2/transcript?limit=10" \
  -H "Authorization: $SANDCHEST_API_KEY"

expected shape

{
  "page_details": { "limit": 10, "result_count": 0, "current_url": "...", "prev_url": null, "next_url": null },
  "transcripts": []
}

If you get {"error":"A valid Sandchest API key is required."}, the key is missing, misspelled or revoked. Start at the Quickstart.

Next#

Quickstart — get a key and your first transcript in about two minutes.