diff --git a/examples/acp-agent/tests/acp.snapshot.ts b/examples/acp-agent/tests/acp.snapshot.ts
index 94f18e64d3..7d19f44bb5 100644
--- a/examples/acp-agent/tests/acp.snapshot.ts
+++ b/examples/acp-agent/tests/acp.snapshot.ts
@@ -54,6 +54,11 @@ const SCENARIOS: Scenario[] = [
   { name: 'tool-call-turn', hasModelTurn: true, recorded: true },
   { name: 'todo-plan', hasModelTurn: true, recorded: true },
   { name: 'workspace-edit', hasModelTurn: true, recorded: true },
+  { name: 'fs-read', hasModelTurn: true, recorded: true },
+  { name: 'fs-write', hasModelTurn: true, recorded: true },
+  { name: 'fs-edit', hasModelTurn: true, recorded: true },
+  { name: 'fs-write-overwrite', hasModelTurn: true, recorded: true },
+  { name: 'fs-read-window', hasModelTurn: true, recorded: true },
   { name: 'multi-turn', hasModelTurn: true, recorded: true },
   { name: 'error-finish', hasModelTurn: true, recorded: false },
   { name: 'cancel', hasModelTurn: true, recorded: false },
diff --git a/examples/acp-agent/tests/snapshots/fs-edit/input.json b/examples/acp-agent/tests/snapshots/fs-edit/input.json
new file mode 100644
index 0000000000..1455aa373c
--- /dev/null
+++ b/examples/acp-agent/tests/snapshots/fs-edit/input.json
@@ -0,0 +1,7 @@
+{
+  "steps": [
+    { "op": "initialize" },
+    { "op": "newSession" },
+    { "op": "prompt", "text": "First use the read tool to read config.txt in the current directory. Then use the edit tool (NOT bash) to replace the literal text DEBUG with RELEASE in that file. Then reply with exactly the single word DONE." }
+  ]
+}
diff --git a/examples/acp-agent/tests/snapshots/fs-edit/session.jsonl b/examples/acp-agent/tests/snapshots/fs-edit/session.jsonl
new file mode 100644
index 0000000000..0e6b253480
--- /dev/null
+++ b/examples/acp-agent/tests/snapshots/fs-edit/session.jsonl
@@ -0,0 +1,147 @@
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+line one
+line two
+line three
+line four
+line five
+line six
+line seven
+line eight
+line nine
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diff --git a/examples/acp-agent/tests/snapshots/fs-read/workspace/greeting.txt b/examples/acp-agent/tests/snapshots/fs-read/workspace/greeting.txt
new file mode 100644
index 0000000000..ce01362503
--- /dev/null
+++ b/examples/acp-agent/tests/snapshots/fs-read/workspace/greeting.txt
@@ -0,0 +1 @@
+hello
diff --git a/examples/acp-agent/tests/snapshots/fs-write-overwrite/input.json b/examples/acp-agent/tests/snapshots/fs-write-overwrite/input.json
new file mode 100644
index 0000000000..585ec3ebed
--- /dev/null
+++ b/examples/acp-agent/tests/snapshots/fs-write-overwrite/input.json
@@ -0,0 +1,7 @@
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+  ]
+}
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new file mode 100644
index 0000000000..1d234c2dd4
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diff --git a/examples/acp-agent/tests/snapshots/fs-write-overwrite/workspace/data.txt b/examples/acp-agent/tests/snapshots/fs-write-overwrite/workspace/data.txt
new file mode 100644
index 0000000000..b2745f6f48
--- /dev/null
+++ b/examples/acp-agent/tests/snapshots/fs-write-overwrite/workspace/data.txt
@@ -0,0 +1 @@
+original contents
diff --git a/examples/acp-agent/tests/snapshots/fs-write/input.json b/examples/acp-agent/tests/snapshots/fs-write/input.json
new file mode 100644
index 0000000000..1512e93735
--- /dev/null
+++ b/examples/acp-agent/tests/snapshots/fs-write/input.json
@@ -0,0 +1,7 @@
+{
+  "steps": [
+    { "op": "initialize" },
+    { "op": "newSession" },
+    { "op": "prompt", "text": "Use the write tool (NOT bash) to create a file named notes.txt in the current directory containing exactly the single line: hello world. Then reply with exactly the single word DONE." }
+  ]
+}
diff --git a/examples/acp-agent/tests/snapshots/fs-write/session.jsonl b/examples/acp-agent/tests/snapshots/fs-write/session.jsonl
new file mode 100644
index 0000000000..533ec83084
--- /dev/null
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