Security
PKCE Code Verifier & Challenge Generator
Generate, validate and verify OAuth2 / OIDC PKCE (RFC 7636) code_verifier and S256 code_challenge pairs. Three modes: (1) generate a fresh verifier + challenge from cryptographically secure random bytes at 256/384/512/768-bit entropy, (2) audit a verifier you already have against the RFC — length (43–128), charset [A-Za-z0-9-._~] and ≥256-bit entropy, and (3) verify a verifier/challenge pair by recomputing BASE64URL(SHA256(verifier)). Optionally build the full authorization-request URL and token-exchange body. Complements the generic nonce-generator (which only emits a verifier+challenge pair) with RFC-compliance auditing and pair verification.
Quick start
Call this tool from your code in three languages.
curl -X POST 'https://api.elysiatools.com/en/api/tools/pkce-code-verifier-generator' \
-H 'Content-Type: application/json' \
-d '{"mode":"generate","byteLength":"64","verifier":"","challenge":"","authEndpoint":"","clientId":"","redirectUri":""}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
POST https://api.elysiatools.com/en/api/tools/pkce-code-verifier-generatorParameters
| Name | Type | Required | Description |
|---|---|---|---|
| mode | select | No | — |
| byteLength | select | No | — |
| verifier | textarea | No | — |
| challenge | textarea | No | — |
| authEndpoint | text | No | — |
| clientId |
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:
{
"mcpServers": {
"elysiatools-pkce-code-verifier-generator": {
"name": "pkce-code-verifier-generator",
"description": "Generate, validate and verify OAuth2 / OIDC PKCE (RFC 7636) code_verifier and S256 code_challenge pairs. Three modes: (1) generate a fresh verifier + challenge from cryptographically secure random bytes at 256/384/512/768-bit entropy, (2) audit a verifier you already have against the RFC — length (43–128), charset [A-Za-z0-9-._~] and ≥256-bit entropy, and (3) verify a verifier/challenge pair by recomputing BASE64URL(SHA256(verifier)). Optionally build the full authorization-request URL and token-exchange body. Complements the generic nonce-generator (which only emits a verifier+challenge pair) with RFC-compliance auditing and pair verification.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=pkce-code-verifier-generator",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "pkce-code-verifier-generator",
"arguments": {
"mode": "generate",
"byteLength": "64",
"verifier": "",
"challenge": "",
"authEndpoint": "",
"clientId": "",
"redirectUri": ""
}
}
}