How Verification Works

Every delta you submit to PacSpace goes through a multi-step verification pipeline. The result is a cryptographic proof that your data was recorded accurately, in order, and hasn't been tampered with.

The Verification Pipeline#

1. You emit a delta#

Send a POST /balance/delta request with your delta payload — the customer, amount, reason, and any metadata you want to attach.

{
  "customerId": "cust_8xKj2m",
  "amount": -42.50,
  "reason": "usage_charge",
  "referenceId": "inv_20260211_001",
  "metadata": { "plan": "growth" }
}

2. PacSpace computes a content hash#

As soon as your delta arrives, PacSpace canonicalizes the payload and computes a content hash — a unique fingerprint of that exact data. If even a single character changes, the hash is completely different.

3. Deltas are batched and a proof hash is computed#

Multiple deltas are grouped into a batch. PacSpace builds a Merkle tree from the batch's content hashes and computes a single root value — the proof hash. This proof hash cryptographically represents every delta in the batch.

4. The proof hash is committed to PacSpace's verification layer#

The proof hash is written to PacSpace's independent verification layer, creating a permanent, tamper-evident record. Once committed, the data cannot be altered without invalidating the proof.

5. You receive a delta.verified webhook#

PacSpace sends a webhook to your registered endpoint with the complete proof packet — including the proof hash, content hash, item hashes, and verification metadata.

{
  "event": "delta.verified",
  "data": {
    "receiptId": "rcpt_a1b2c3d4",
    "proof": {
      "proofHash": "0x8f3a...",
      "contentHash": "0x2d4e...",
      "previousProofHash": "0x1c7b...",
      "itemHashes": ["0x2d4e...", "0x9f1a..."]
    }
  }
}

6. A checkpoint locks the period#

At the end of each period, PacSpace creates a checkpoint — a single root hash computed over all deltas in that period. This checkpoint locks the entire period's data into one verifiable value and fires a checkpoint.verified webhook.

How Deltas Form a Chain#

Each delta's proof hash references the previous delta's proof hash, creating a hash chain. This means:

• You can verify any delta links back to the one before it
• Inserting, removing, or reordering deltas breaks the chain
• The full history is auditable from any point

Delta 0        Delta 1        Delta 2
proofHash₀ ──→ proofHash₁ ──→ proofHash₂
               (includes       (includes
                prevHash₀)      prevHash₁)

Key Terms#

What You Can Do With This#

• Audit any delta — Recompute the content hash and verify it against the proof hash
• Detect tampering — Any modification breaks the hash chain
• Prove history — Walk the chain from any delta back to the beginning
• Independent verification — You don't have to trust PacSpace; you can verify the proofs yourself