diff --git a/cachy.jsonl b/cachy.jsonl
index 5e3f037..6c423cd 100644
--- a/cachy.jsonl
+++ b/cachy.jsonl
@@ -19,3 +19,4 @@
 {"key": "d4142886", "response": "{\n  \"candidates\": [\n    {\n      \"content\": {\n        \"parts\": [\n          {\n            \"text\": \"Concurrency\\n\"\n          }\n        ],\n        \"role\": \"model\"\n      },\n      \"finishReason\": \"STOP\",\n      \"avgLogprobs\": -0.29076665639877319\n    }\n  ],\n  \"usageMetadata\": {\n    \"promptTokenCount\": 10,\n    \"candidatesTokenCount\": 2,\n    \"totalTokenCount\": 12,\n    \"promptTokensDetails\": [\n      {\n        \"modality\": \"TEXT\",\n        \"tokenCount\": 10\n      }\n    ],\n    \"candidatesTokensDetails\": [\n      {\n        \"modality\": \"TEXT\",\n        \"tokenCount\": 2\n      }\n    ]\n  },\n  \"modelVersion\": \"gemini-2.0-flash\",\n  \"responseId\": \"1gvIaLDAGe2kvdIPsY6--Q0\"\n}\n"}
 {"key": "fe23aa62", "response": "data: {\"candidates\": [{\"content\": {\"parts\": [{\"text\": \"Concurrency\"}],\"role\": \"model\"}}],\"usageMetadata\": {\"promptTokenCount\": 12,\"totalTokenCount\": 12,\"promptTokensDetails\": [{\"modality\": \"TEXT\",\"tokenCount\": 12}]},\"modelVersion\": \"gemini-2.0-flash\",\"responseId\": \"1gvIaKSQOt3h1PIPwJO12Ac\"}\r\n\r\ndata: {\"candidates\": [{\"content\": {\"parts\": [{\"text\": \"\\n\"}],\"role\": \"model\"},\"finishReason\": \"STOP\"}],\"usageMetadata\": {\"promptTokenCount\": 11,\"candidatesTokenCount\": 2,\"totalTokenCount\": 13,\"promptTokensDetails\": [{\"modality\": \"TEXT\",\"tokenCount\": 11}],\"candidatesTokensDetails\": [{\"modality\": \"TEXT\",\"tokenCount\": 2}]},\"modelVersion\": \"gemini-2.0-flash\",\"responseId\": \"1gvIaKSQOt3h1PIPwJO12Ac\"}\r\n\r\n"}
 {"key": "c90feca2", "response": "{\"id\":\"msg_01HpiQTg22STqarE33JnuHdt\",\"type\":\"message\",\"role\":\"assistant\",\"model\":\"claude-sonnet-4-20250514\",\"content\":[{\"type\":\"tool_use\",\"id\":\"toolu_0182nVBg1pTYTadKxS5qgCt4\",\"name\":\"get_current_weather\",\"input\":{\"location\":\"Reims\"}}],\"stop_reason\":\"tool_use\",\"stop_sequence\":null,\"usage\":{\"input_tokens\":427,\"cache_creation_input_tokens\":0,\"cache_read_input_tokens\":0,\"cache_creation\":{\"ephemeral_5m_input_tokens\":0,\"ephemeral_1h_input_tokens\":0},\"output_tokens\":57,\"service_tier\":\"standard\"}}"}
+{"key": "79d28180", "response": "{\n  \"id\": \"resp_07096c5fa7f05f3600692af5de73f0819c85e63a30484d9b65\",\n  \"object\": \"response\",\n  \"created_at\": 1764423134,\n  \"status\": \"completed\",\n  \"background\": false,\n  \"billing\": {\n    \"payer\": \"developer\"\n  },\n  \"error\": null,\n  \"incomplete_details\": null,\n  \"instructions\": null,\n  \"max_output_tokens\": null,\n  \"max_tool_calls\": null,\n  \"model\": \"gpt-4.1-2025-04-14\",\n  \"output\": [\n    {\n      \"id\": \"msg_07096c5fa7f05f3600692af5df34a8819ca053230b7e0ede57\",\n      \"type\": \"message\",\n      \"status\": \"completed\",\n      \"content\": [\n        {\n          \"type\": \"output_text\",\n          \"annotations\": [],\n          \"logprobs\": [],\n          \"text\": \"Hello! \\ud83d\\ude0a How can I help you today?\"\n        }\n      ],\n      \"role\": \"assistant\"\n    }\n  ],\n  \"parallel_tool_calls\": true,\n  \"previous_response_id\": null,\n  \"prompt_cache_key\": null,\n  \"prompt_cache_retention\": null,\n  \"reasoning\": {\n    \"effort\": null,\n    \"summary\": null\n  },\n  \"safety_identifier\": null,\n  \"service_tier\": \"default\",\n  \"store\": true,\n  \"temperature\": 1.0,\n  \"text\": {\n    \"format\": {\n      \"type\": \"text\"\n    },\n    \"verbosity\": \"medium\"\n  },\n  \"tool_choice\": \"auto\",\n  \"tools\": [],\n  \"top_logprobs\": 0,\n  \"top_p\": 1.0,\n  \"truncation\": \"disabled\",\n  \"usage\": {\n    \"input_tokens\": 9,\n    \"input_tokens_details\": {\n      \"cached_tokens\": 0\n    },\n    \"output_tokens\": 11,\n    \"output_tokens_details\": {\n      \"reasoning_tokens\": 0\n    },\n    \"total_tokens\": 20\n  },\n  \"user\": null,\n  \"metadata\": {}\n}"}
diff --git a/cachy/_modidx.py b/cachy/_modidx.py
index e4be19d..2837235 100644
--- a/cachy/_modidx.py
+++ b/cachy/_modidx.py
@@ -9,6 +9,7 @@
                             'cachy.core._apply_sync_patch': ('core.html#_apply_sync_patch', 'cachy/core.py'),
                             'cachy.core._cache': ('core.html#_cache', 'cachy/core.py'),
                             'cachy.core._key': ('core.html#_key', 'cachy/core.py'),
+                            'cachy.core._norm_multipart': ('core.html#_norm_multipart', 'cachy/core.py'),
                             'cachy.core._should_cache': ('core.html#_should_cache', 'cachy/core.py'),
                             'cachy.core._write_cache': ('core.html#_write_cache', 'cachy/core.py'),
                             'cachy.core.disable_cachy': ('core.html#disable_cachy', 'cachy/core.py'),
diff --git a/cachy/core.py b/cachy/core.py
index ceafb86..5f535c8 100644
--- a/cachy/core.py
+++ b/cachy/core.py
@@ -6,7 +6,7 @@
 __all__ = ['doms', 'enable_cachy', 'disable_cachy']
 
 # %% ../nbs/00_core.ipynb
-import hashlib,httpx,json
+import hashlib,httpx,json,re
 from fastcore.utils import *
 
 # %% ../nbs/00_core.ipynb
@@ -25,10 +25,18 @@ def _cache(key, cfp):
 def _write_cache(key, content, cfp):
     with open(cfp, "a") as f: f.write(json.dumps({"key":key, "response": content})+"\n")
 
+# %% ../nbs/00_core.ipynb
+def _norm_multipart(r):
+    ct = r.headers.get('content-type', '')
+    match = re.search(r'boundary=([a-f0-9]{32})', ct)
+    if match: return r.content.replace(match.group(1).encode(), b'BOUNDARY')
+    return r.content
+
 # %% ../nbs/00_core.ipynb
 def _key(r, is_stream=False):
     "Create a unique, deterministic id from the request `r`."
-    return hashlib.sha256(f"{r.url.host}{is_stream}".encode() + r.content).hexdigest()[:8]
+    r.read()
+    return hashlib.sha256(f"{r.url.host}{is_stream}".encode() + _norm_multipart(r)).hexdigest()[:8]
 
 # %% ../nbs/00_core.ipynb
 def _apply_async_patch(cfp, doms):    
diff --git a/nbs/00_core.ipynb b/nbs/00_core.ipynb
index 14917d0..7642a40 100644
--- a/nbs/00_core.ipynb
+++ b/nbs/00_core.ipynb
@@ -71,7 +71,7 @@
    "outputs": [],
    "source": [
     "#| export\n",
-    "import hashlib,httpx,json\n",
+    "import hashlib,httpx,json,re\n",
     "from fastcore.utils import *"
    ]
   },
@@ -407,6 +407,27 @@
     "First let's include an `is_stream` bool in our hash so that a non-streamed request will generate a different key to the same request when streamed. "
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#| export\n",
+    "def _norm_multipart(r):\n",
+    "    ct = r.headers.get('content-type', '')\n",
+    "    match = re.search(r'boundary=([a-f0-9]{32})', ct)\n",
+    "    if match: return r.content.replace(match.group(1).encode(), b'BOUNDARY')\n",
+    "    return r.content"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Here, we use `httpx.Request.read()` which reads the streaming request body into memory (storing it in `_content`) so that `r.content` can be accessed, and it's safe to call multiple times since it's a no-op if already read. For multipart requests, we normalize the content by replacing httpx's randomly-generated boundary string with a fixed value, ensuring identical requests produce the same cache key."
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
@@ -416,7 +437,8 @@
     "#| exports\n",
     "def _key(r, is_stream=False):\n",
     "    \"Create a unique, deterministic id from the request `r`.\"\n",
-    "    return hashlib.sha256(f\"{r.url.host}{is_stream}\".encode() + r.content).hexdigest()[:8]"
+    "    r.read()\n",
+    "    return hashlib.sha256(f\"{r.url.host}{is_stream}\".encode() + _norm_multipart(r)).hexdigest()[:8]"
    ]
   },
   {