diff --git a/apps/server/src/persistence/Errors.test.ts b/apps/server/src/persistence/Errors.test.ts
index 680a362e20a..4223273aca7 100644
--- a/apps/server/src/persistence/Errors.test.ts
+++ b/apps/server/src/persistence/Errors.test.ts
@@ -2,7 +2,7 @@ import { assert, it } from "@effect/vitest";
 import * as Effect from "effect/Effect";
 import * as Schema from "effect/Schema";
 
-import { PersistenceDecodeError, PersistenceSqlError } from "./Errors.ts";
+import { PersistenceDecodeError, PersistenceSqlError, toPersistenceSqlError } from "./Errors.ts";
 
 const decodeRuntimePayload = Schema.decodeUnknownEffect(
   Schema.Struct({
@@ -25,6 +25,56 @@ it("keeps SQL operation context without a tautological detail", () => {
   assert.equal(error.message, "SQL error in AuthSessionRepository.list:query");
 });
 
+it("names the SQLite condition by its normalized result code", () => {
+  const cause = Object.assign(new Error("UNIQUE constraint failed: orders.customer_email"), {
+    errcode: 1555,
+    errstr: "constraint failed",
+  });
+  const error = toPersistenceSqlError("OrchestrationCommandReceiptRepository.upsert:query")(cause);
+
+  assert.equal(error.detail, "SQLITE(1555) constraint failed");
+  assert.equal(error.cause, cause);
+});
+
+it("reads the condition through a wrapping driver error", () => {
+  const driver = Object.assign(new Error("locked"), { errcode: 5, errstr: "database is locked" });
+  const error = toPersistenceSqlError("AuthSessionRepository.list:query")(
+    new Error("Failed to prepare statement", { cause: driver }),
+  );
+
+  assert.equal(error.detail, "SQLITE(5) database is locked");
+});
+
+it("keeps the driver's own prose out of the message", () => {
+  const cause = Object.assign(new Error("UNIQUE constraint failed: orders.customer_email"), {
+    errcode: 1555,
+    errstr: "constraint failed",
+  });
+  const error = toPersistenceSqlError("AuthSessionRepository.create:query")(cause);
+
+  assert.ok(!error.message.includes("customer_email"));
+});
+
+it("omits a detail for a cause it cannot categorize", () => {
+  const error = toPersistenceSqlError("AuthSessionRepository.list:query")(new Error("unhelpful"));
+
+  assert.equal(error.detail, undefined);
+  assert.equal(error.message, "SQL error in AuthSessionRepository.list:query");
+});
+
+it.effect("summarizes a schema cause by issue tag instead of by rejected value", () =>
+  Effect.gen(function* () {
+    const rejectedPayload = "sql-mapper-secret-sentinel";
+    const cause = yield* Effect.flip(
+      decodeRuntimePayload({ runtimePayload: { attempt: rejectedPayload } }),
+    );
+    const error = toPersistenceSqlError("ProviderSessionRuntimeRepository.list:query")(cause);
+
+    assert.ok(error.detail !== undefined);
+    assert.ok(!error.message.includes(rejectedPayload));
+  }),
+);
+
 it.effect("maps schema errors without copying rejected payloads into diagnostics", () =>
   Effect.gen(function* () {
     const rejectedPayload = "runtime-payload-secret-sentinel";
diff --git a/apps/server/src/persistence/Errors.ts b/apps/server/src/persistence/Errors.ts
index 03edaec77d6..bce1dd1f36b 100644
--- a/apps/server/src/persistence/Errors.ts
+++ b/apps/server/src/persistence/Errors.ts
@@ -73,13 +73,45 @@ const isPersistenceSqlError = Schema.is(PersistenceSqlError);
 const isPersistenceDecodeError = Schema.is(PersistenceDecodeError);
 
 // Kept for orchestration/projection call sites, which are being revamped separately.
+/**
+ * SQLite names its condition through a fixed result-code table, so the code and
+ * its canonical string are bounded and carry no query data. The driver message
+ * is not bounded: a constraint failure spells out the table and column it hit.
+ * Only the normalized pair is carried here; `cause` keeps everything else.
+ */
+function sqliteCondition(cause: unknown): string | undefined {
+  let value: unknown = cause;
+  for (let depth = 0; depth < 4 && typeof value === "object" && value !== null; depth += 1) {
+    const { errcode, errstr } = value as { errcode?: unknown; errstr?: unknown };
+    if (typeof errcode === "number" && typeof errstr === "string") {
+      return `SQLITE(${errcode}) ${errstr}`;
+    }
+    value = (value as { cause?: unknown }).cause;
+  }
+  return undefined;
+}
+
+/**
+ * A rejected payload must never reach diagnostics, so a schema failure
+ * contributes only its issue tags, and a driver failure only its normalized
+ * condition. Anything the mapper cannot categorize leaves the detail unset.
+ */
+function describeSqlCause(cause: unknown): string | undefined {
+  if (Schema.isSchemaError(cause)) return summarizeSchemaIssue(cause.issue);
+  return sqliteCondition(cause);
+}
+
 export function toPersistenceSqlError(operation: string) {
-  return (cause: unknown): PersistenceSqlError =>
-    new PersistenceSqlError({
+  return (cause: unknown): PersistenceSqlError => {
+    // Restating the operation as the detail only doubled it in the message and
+    // buried the cause; `message` already reads well without a detail.
+    const detail = describeSqlCause(cause);
+    return new PersistenceSqlError({
       operation,
-      detail: `Failed to execute ${operation}`,
+      ...(detail === undefined ? {} : { detail }),
       cause,
     });
+  };
 }
 
 // Kept for orchestration/projection call sites, which are being revamped separately.