diff --git a/packages/session/session-persistence-jsonl/tests/jsonl.spec.ts b/packages/session/session-persistence-jsonl/tests/jsonl.spec.ts
index 390d0e9048..7f760c7281 100644
--- a/packages/session/session-persistence-jsonl/tests/jsonl.spec.ts
+++ b/packages/session/session-persistence-jsonl/tests/jsonl.spec.ts
@@ -237,6 +237,26 @@ describe('SessionPersistenceJsonl: durability and crash semantics', () => {
     expect(await ctx.sessionPersistence.readRaw(m.id)).toBeUndefined()
   })
 
+  it('readRaw rejects a corrupt header line instead of exporting it', async () => {
+    const m = meta('raw-corrupt', '/work')
+    await ctx.sessionPersistence.create(m)
+    await ctx.sessionPersistence.append(m.id, oneTurnLog())
+    await writeFile(rawLogPath(root, '/work', m.id), 'not a header line\n{"type":"turn/start","seq":0}\n')
+    await expect(ctx.sessionPersistence.readRaw(m.id)).rejects.toThrow(/corrupt session log/)
+  })
+
+  it('readRaw retries when the file revision changes during the read', async () => {
+    const m = meta('raw-revision-race', '/work')
+    await ctx.sessionPersistence.create(m)
+    await ctx.sessionPersistence.append(m.id, oneTurnLog())
+    statRace.path = rawLogPath(root, '/work', m.id)
+
+    const raw = await ctx.sessionPersistence.readRaw(m.id)
+    expect(raw).toBeDefined()
+    // Two stat calls per iteration; the mocked revision change forces a retry.
+    expect(statRace.reads).toBe(4)
+  })
+
   it('keeps the same location on resume and gives a fork its own location', async () => {
     const parent = meta('location-parent', '/work')
     const parentLocation = ctx.sessionPersistence.locate(parent)
diff --git a/packages/session/session-persistence-jsonl/tests/zstd.spec.ts b/packages/session/session-persistence-jsonl/tests/zstd.spec.ts
index 37d3e6c13b..c54dca4c08 100644
--- a/packages/session/session-persistence-jsonl/tests/zstd.spec.ts
+++ b/packages/session/session-persistence-jsonl/tests/zstd.spec.ts
@@ -377,6 +377,18 @@ describe('SessionPersistenceJsonl: default Zstandard encoding', () => {
     expect(scanned.events.map(event => event.type)).toEqual(oneTurnLog().map(event => event.type))
   })
 
+  it('readRaw is undefined for a zstd artifact that carries no frame', async () => {
+    const root = await freshRoot()
+    const ctx = await mount(root)
+    const header = meta('raw-zero-frame', '/work')
+    await ctx.sessionPersistence.create(header)
+    await ctx.sessionPersistence.append(header.id, oneTurnLog())
+    // Overwrite the physical artifact with a short buffer: frame scanning
+    // answers zero frames before any magic check, so readRaw reports no artifact.
+    await writeFile(logPath(root, '/work', header.id, 'zstd'), Buffer.alloc(0))
+    expect(await ctx.sessionPersistence.readRaw(header.id)).toBeUndefined()
+  })
+
   it('resolves the default when a programmatic wrapper bypasses Loader schema normalization', async () => {
     const root = await freshRoot()
     const ctx = new Context()
diff --git a/packages/session/session-persistence/src/index.ts b/packages/session/session-persistence/src/index.ts
index 0889a60edf..aedfd8df5a 100644
--- a/packages/session/session-persistence/src/index.ts
+++ b/packages/session/session-persistence/src/index.ts
@@ -106,9 +106,9 @@ export abstract class SessionPersistence extends Service {
    * @returns the raw artifact plus its parsed header, or `undefined` when the
    * session is absent or the backend owns no per-session artifact.
    */
-  readRaw(_id: SessionId, signal?: AbortSignal): Promise<SessionRawArtifact | undefined> {
+  async readRaw(_id: SessionId, signal?: AbortSignal): Promise<SessionRawArtifact | undefined> {
     signal?.throwIfAborted()
-    return Promise.resolve(undefined)
+    return undefined
   }
 
   /**
diff --git a/packages/session/session-persistence/tests/persistence.spec.ts b/packages/session/session-persistence/tests/persistence.spec.ts
index d3e715b085..99f6acc756 100644
--- a/packages/session/session-persistence/tests/persistence.spec.ts
+++ b/packages/session/session-persistence/tests/persistence.spec.ts
@@ -246,6 +246,18 @@ runPersistenceContract('memory', async () => {
   }
 })
 
+describe('the inherited readRaw default', () => {
+  it('answers undefined and honors an aborted signal', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SessionStore)
+    await ctx.plugin(MemoryPersistence)
+    expect(await ctx.sessionPersistence.readRaw(SessionId('any-session'))).toBeUndefined()
+    await expect(
+      ctx.sessionPersistence.readRaw(SessionId('any-session'), AbortSignal.abort()),
+    ).rejects.toThrow()
+  })
+})
+
 // Each fixture shares one map across mounts. No `corruptTail` is supplied because map writes are
 // atomic; the suite asserts that skip while JSONL and SQLite cover the repair branch.
 runCoordinatorContract('memory', async (): Promise<CoordinatorFixture> => {