Skip to content
BEAD

JWT Builder

Build a JWT — set headers, claims, and sign with HS256/384/512 entirely in your browser.

DeveloperEncoding
Quick claims:
JWT

🔒 Signing uses SubtleCrypto in your browser. Secrets never leave your machine.

</>Use this tool programmaticallycurl · JavaScript · MCP

Same tool, callable from any HTTP client or from Claude (via MCP). Anonymous: 100 req/day per IP. Sign up for 1,000 req/day.

curl
curl https://api.b-e-a-d.com/tools/jwt-builder/run \
  -H "Content-Type: application/json" \
  -d '{
  "alg": "HS256",
  "payload": {}
}'
JavaScript (fetch)
const res = await fetch("https://api.b-e-a-d.com/tools/jwt-builder/run", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
  "alg": "HS256",
  "payload": {}
}),
});
const data = await res.json();
console.log(data.result);
MCP (Claude Desktop / Claude Code)
# In Claude Desktop / Claude Code, add to your MCP config:
{
  "mcpServers": {
    "bead": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://mcp.b-e-a-d.com"]
    }
  }
}

# Then ask Claude to call:
mcp__bead__bead_jwt_builder

Full reference: developer docs · OpenAPI spec

About this tool

Builds and signs JWTs in your browser. Symmetric algorithms only —HS256, HS384, HS512 — plus none for unsigned tokens (testing only — never accept alg: none in production).

For RS/ES signing you need a private key; that's a different beast and out of scope here. To inspect an existing JWT, see the JWT Decoder.

You might also like