From 2a1a7512ae39eea81d10dfdab90912912d088a67 Mon Sep 17 00:00:00 2001
From: Stephen Waits <1+swaits@noreply.git.swaits.com>
Date: Sun, 11 Oct 2026 01:09:40 +0000
Subject: [PATCH] QBO formats for import/export; server-side receipt
 enforcement policy in MCP spec

---
 docs/oracle.md | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/docs/oracle.md b/docs/oracle.md
index 2750d16..1cc073d 100644
--- a/docs/oracle.md
+++ b/docs/oracle.md
@@ -33,11 +33,15 @@ is exactly zero. New invariants get new properties. (Later: graduate to
 `proptest` with shrinking.)
 
 **Layer 3 — GnuCash diff harness (roadmap phase 3).** A `ledger-oracle` crate
-will: import fixture books into GnuCash's XML format (or drive GnuCash
-headless), run both engines, and diff `snapshot()` output automatically —
-`cargo xtask oracle`. This is the direct analog of storytold's
-`cargo xtask corpus` / `oracle_diff`. Until it exists, Layers 1 and 2 are
-the oracle, and they are not optional.
+will run fixture books through our engine and through GnuCash headless, then
+diff `snapshot()` output automatically — `cargo xtask oracle`. This is the
+direct analog of storytold's `cargo xtask corpus` / `oracle_diff`. Note the
+distinction: GnuCash is the *behavioral* oracle, not a file-format target
+(Stephen: "for file format import/export I could not give a single shit
+about GnuCash XML — QBO is all that matters"). The harness feeds fixtures to
+GnuCash via whatever it imports reliably (QIF/OFX) or its Python bindings;
+the exact mechanism is decided at implementation time. Until the harness
+exists, Layers 1 and 2 are the oracle, and they are not optional.
 
 ## What the oracle does NOT cover (yet)