Xahau Hooks Docs

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Binary Visualizer ​

A browser tool that decodes a serialized Xahau blob — a transaction, a ledger entry, a manifest, or any other STObject — field by field, showing the type-code, field-code, and raw payload bytes for each field in order.

Why use it ​

Hooks work entirely in terms of raw serialized bytes: otxn_field and slot_subfield/sto_subfield hand you an offset and length into a byte buffer, not a parsed structure, and building an emitted transaction template (as in the Transaction Builder) means laying out field headers, VL prefixes, and amount encodings by hand. When a hook's byte math doesn't line up — an unexpected field length, an off-by-one offset, a mis-encoded amount — the fastest way to find out why is to paste the exact bytes into a visualizer and see the field boundaries the ledger itself would see. It turns "what does this hex blob actually contain" from a manual nibble-counting exercise into a click-through breakdown.

It is also useful independent of debugging a specific hook: reading an sfHookExecutions array from transaction metadata, inspecting an sfEmitDetails object you built by hand, or checking what a ltHOOK_DEFINITION or ltHOOK_STATE object looks like on the wire.

How to use it ​

  1. Paste hex, base64, or JSON into the single text box, then click outside it (or it re-runs on every change). The tool auto-detects which of the three it is — including base64-encoded JSON — and decodes accordingly.
  2. For hex/base64 input, it walks the bytes and prints, per field, in order: the type-code, the field-code, and the field's raw payload — indenting nested STObject/STArray fields and marking their end markers.
  3. Amount fields get a dedicated breakdown instead of a flat payload: for native XAH it splits out the XAH-bit and sign bit from the drops value; for an IOU it splits out the not-XAH bit, sign bit, 8-bit exponent (both the raw stored value and the adjusted exponent), the mantissa, the 3-letter currency code, and the 20-byte issuer — the same sign/exponent/mantissa layout documented in XFL.
  4. Any value inside a decoded JSON blob that looks like hex or base64 becomes clickable — clicking it re-decodes just that inner value, and a "Go up" link returns to the outer blob. This is convenient for drilling from a transaction's JSON down into one serialized inner blob (for example a Blob-typed field) without re-copying it by hand.
  5. It ships with its own default field definitions (def.json), which already include Xahau's Hook fields, so nothing extra needs to be loaded for typical Xahau blobs. A different field-definitions JSON can be supplied via a query string, e.g. ?path/to/definitions.json, if you need to decode against a different field set.

Worked example ​

Pasting the 49-byte serialized sfAmount field for an IOU amount of 1234567.0 USD — the same XFL value used in float_sto's worked example (6198187654261802496) serialized with a placeholder issuer:

61D60462D5077C86000000000000000000000000005553440000000000ABCDEFABCDEFABCDEFABCDEFABCDEFABCDEFABCD

produces a breakdown along these lines:

  • Field: Amount (type 6, field 1 — the single-byte header 0x61).
  • Type: AMOUNT.
  • Flags + Exponent: not-XAH bit 1, sign bit 1 (positive), exponent raw 88 / adjusted -9, plus the first two mantissa bits.
  • Mantissa: 1234567000000000.
  • Currency Code: USD.
  • Issuer: the 20-byte issuer AccountID.

That raw exponent/mantissa split is exactly what float_sto_set would decode into the XFL 6198187654261802496 inside a hook — the visualizer just shows you the same bits without writing any C.