From 6979a20414e2f6deaa37176298f6703d3ee9278c Mon Sep 17 00:00:00 2001
From: Stephen Waits <1+swaits@noreply.git.swaits.com>
Date: Sun, 11 Oct 2026 01:37:12 +0000
Subject: [PATCH] First slice: ledger-store (journal+blobs+sqlite) and
 ledger-mcp (18 tools, receipt policy)

---
 crates/ledger-store/src/error.rs | 59 ++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 crates/ledger-store/src/error.rs

diff --git a/crates/ledger-store/src/error.rs b/crates/ledger-store/src/error.rs
new file mode 100644
index 0000000..5664ef2
--- /dev/null
+++ b/crates/ledger-store/src/error.rs
@@ -0,0 +1,59 @@
+//! Error type for the store.
+
+use thiserror::Error;
+
+/// Every way a store operation can fail.
+#[derive(Debug, Error)]
+pub enum StoreError {
+    /// Filesystem error.
+    #[error("io error: {0}")]
+    Io(#[from] std::io::Error),
+
+    /// SQLite error.
+    #[error("sqlite error: {0}")]
+    Rusqlite(#[from] rusqlite::Error),
+
+    /// JSON error.
+    #[error("json error: {0}")]
+    Json(#[from] serde_json::Error),
+
+    /// The engine rejected the operation. The journal is untouched.
+    #[error("ledger error: {0}")]
+    Ledger(#[from] ledger_core::LedgerError),
+
+    /// The journal failed integrity verification.
+    #[error("journal corrupt: {0}")]
+    JournalCorrupt(String),
+
+    /// Replay produced different ids than the journal recorded.
+    #[error("replay mismatch: {0}")]
+    ReplayMismatch(String),
+
+    /// [`crate::Store::verify`] found divergence.
+    #[error("verify failed: {0}")]
+    VerifyMismatch(String),
+
+    /// A blob's bytes did not match its SHA-256.
+    #[error("blob corrupt: hash mismatch for {0}")]
+    CorruptBlob(String),
+
+    /// Referenced attachment does not exist.
+    #[error("unknown attachment {0}")]
+    UnknownAttachment(u64),
+
+    /// The store's schema is newer than this binary understands.
+    #[error("schema version {0} newer than supported {1}")]
+    SchemaTooNew(u32, u32),
+
+    /// `create` called where a store already exists.
+    #[error("store already exists at {0}")]
+    AlreadyExists(String),
+
+    /// `open` called where no store exists.
+    #[error("store not found at {0}")]
+    NotFound(String),
+
+    /// The requested base currency differs from the store's.
+    #[error("base currency mismatch: store is {0}, requested {1}")]
+    CurrencyMismatch(String, String),
+}