int err;
jsmn_token_encode_s token;

// Create token
err = jsmn_token_init(&token, JSMN_ALG_HS256, "{\"sub\":\"%s\",\"iat\":%d}", "user", time(NULL));

if (!err) {
  // Sign token
  err = jsmn_token_sign(&token, "secret", strlen("secret"));

  // Get token
  if (!err) printf("%.*s", jsmn_token_len(&token), jsmn_token_str(&token));
}

const char *t = \
  "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9."\
  "eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ."\
  "SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c";

int err;
jsmn_token_decode_s token;

// Decode and validate token
err = jsmn_token_decode(&token, "your-256-bit-secret", JSMN_ALG_HS256, t, strlen(t));

if (!err) {
  jsmn_value sub, name;
  int iat;

  // Read claims
  jsmn_token_get_claim_str(&token, "sub", &sub);
  jsmn_token_get_claim_str(&token, "name", &name);
  jsmn_token_get_claim_int(&token, "iat", &iat);
  printf("Hello %.*s!", name.len, name.p);
}