Security
TOTP / HOTP Offline Code Generator
Generate RFC 6238 TOTP (time-based, 6/8 digits, 30/60s step) and RFC 4226 HOTP (counter-based) one-time passwords from a base32 shared secret, fully offline with HMAC-SHA1/256/512, plus an otpauth:// URI for importing into Google Authenticator / Authy
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Quick start
Call this tool from your code in three languages.
cURL
curl -X POST 'https://api.elysiatools.com/en/api/tools/totp-hotp-offline-generator' \
-H 'Content-Type: application/json' \
-d '{"secret":"JBSWY3DPEHPK3PXP","mode":"totp","algorithm":"sha1","digits":6,"period":30,"counter":0,"preview":5,"issuer":"Acme","account":"[email protected]"}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
HTTP
POST https://api.elysiatools.com/en/api/tools/totp-hotp-offline-generatorParameters
| Name | Type | Required | Description |
|---|---|---|---|
| secret | text | Yes | — |
| mode | select | No | — |
| algorithm | select | No | — |
| digits | select | No | — |
| period | select | No | — |
| counter |
MCP integration
Add this tool to your Model Context Protocol server so AI agents can list and call it.
Server configuration
Add this block to your MCP client configuration:
mcp.json
{
"mcpServers": {
"elysiatools-totp-hotp-offline-generator": {
"name": "totp-hotp-offline-generator",
"description": "Generate RFC 6238 TOTP (time-based, 6/8 digits, 30/60s step) and RFC 4226 HOTP (counter-based) one-time passwords from a base32 shared secret, fully offline with HMAC-SHA1/256/512, plus an otpauth:// URI for importing into Google Authenticator / Authy",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=totp-hotp-offline-generator",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
tools/list
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
tools/call
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "totp-hotp-offline-generator",
"arguments": {
"secret": "JBSWY3DPEHPK3PXP",
"mode": "totp",
"algorithm": "sha1",
"digits": 6,
"period": 30,
"counter": 0,
"preview": 5,
"issuer": "Acme",
"account": "[email protected]"
}
}
}Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).