Reference

{
  "version": "1.0",
  "events": [
    {
      "event_type": "envelope.sent",
      "description": "Envelope was sent to signers.",
      "trigger": "after envelope creation and first email dispatch"
    },
    {
      "event_type": "envelope.completed",
      "description": "All signers signed and the final PDF is available.",
      "trigger": "after last signer signs successfully"
    },
    {
      "event_type": "envelope.voided",
      "description": "Envelope was voided by the sender.",
      "trigger": "when envelope status transitions to Voided"
    },
    {
      "event_type": "signer.opened",
      "description": "A signer opened the envelope for the first time.",
      "trigger": "signer's first email link click"
    },
    {
      "event_type": "signer.signed",
      "description": "A single signer completed signing (mid-flow, not final).",
      "trigger": "each signer's completion"
    },
    {
      "event_type": "signer.declined",
      "description": "A signer declined to sign the envelope.",
      "trigger": "when signer clicks Decline"
    },
    {
      "event_type": "signer.delegated",
      "description": "A signer delegated their slot to another person.",
      "trigger": "when signer submits the delegation form"
    }
  ]
}

{
  "algorithm": "HMAC-SHA256",
  "signature_formula": "sha256_hex( hmac( secret, timestamp + \".\" + raw_body ) )",
  "timestamp_tolerance_seconds": 300,
  "dedup_note": "Use X-Inkfree-Delivery as an idempotency key. We retry on failure so the same delivery ID may be sent more than once."
}