diff --git a/openhands-sdk/openhands/sdk/llm/llm.py b/openhands-sdk/openhands/sdk/llm/llm.py
index 2dd49d7164..127715c863 100644
--- a/openhands-sdk/openhands/sdk/llm/llm.py
+++ b/openhands-sdk/openhands/sdk/llm/llm.py
@@ -344,6 +344,15 @@ class LLM(BaseModel, RetryMixin, NonNativeToolCallingMixin):
         json_schema_extra=field_meta(),
     )
 
+    # AIMLAPI (https://aimlapi.com) partner attribution, sent only on calls
+    # routed through the ``aiml`` LiteLLM provider so AIMLAPI can attribute
+    # traffic to OpenHands (see AIMLAPI_PARTNER_ID in the CLI's aimlapi/config.py
+    # for the sibling implementation).
+    aimlapi_partner_id: str = Field(
+        default="part_uDVajKg3xPLrOdNdQetOtoGA",
+        json_schema_extra=field_meta(),
+    )
+
     num_retries: int = Field(default=5, ge=0, json_schema_extra=field_meta())
     retry_multiplier: float = Field(default=8.0, ge=0, json_schema_extra=field_meta())
     retry_min_wait: int = Field(default=8, ge=0, json_schema_extra=field_meta())
@@ -822,6 +831,21 @@ def _openrouter_headers(self) -> dict[str, str]:
             headers["X-Title"] = self.openrouter_app_name
         return headers
 
+    def _aiml_headers(self) -> dict[str, str]:
+        """Build AIMLAPI partner-attribution headers for per-call use.
+
+        Unlike ``_openrouter_headers()``, gated on the parsed LiteLLM provider
+        being ``aiml`` — an unrecognized ``X-AIMLAPI-Partner-ID`` header would
+        just be dead weight on every other provider's request.
+        """
+        if self._provider_info is None or self._provider_info.name != "aiml":
+            return {}
+        headers: dict[str, str] = {}
+        if self.aimlapi_partner_id:
+            headers["X-AIMLAPI-Partner-ID"] = self.aimlapi_partner_id
+            headers["X-AIMLAPI-Source"] = "agent"
+        return headers
+
     def _aws_kwargs(self) -> dict[str, str]:
         """Build kwargs dict for AWS params to pass to litellm calls."""
         kw: dict[str, str] = {}
diff --git a/openhands-sdk/openhands/sdk/llm/options/common.py b/openhands-sdk/openhands/sdk/llm/options/common.py
index d6b4602e37..30da86baf9 100644
--- a/openhands-sdk/openhands/sdk/llm/options/common.py
+++ b/openhands-sdk/openhands/sdk/llm/options/common.py
@@ -27,9 +27,10 @@ def apply_extra_headers(user_kwargs: dict[str, Any], llm: LLM) -> dict[str, Any]
     """Return a new dict with the LLM's extra headers applied.
 
     Propagates ``llm.extra_headers`` when the caller did not set its own, then
-    merges the OpenRouter attribution headers. These go through ``extra_headers``
-    rather than ``os.environ`` so they don't leak across conversations in a
-    multi-tenant server (see issue #3138). User-supplied headers win.
+    merges the OpenRouter and AIMLAPI attribution headers. These go through
+    ``extra_headers`` rather than ``os.environ`` so they don't leak across
+    conversations in a multi-tenant server (see issue #3138). User-supplied
+    headers win.
 
     - Pure and deterministic; does not mutate inputs
     """
@@ -43,6 +44,11 @@ def apply_extra_headers(user_kwargs: dict[str, Any], llm: LLM) -> dict[str, Any]
         existing = out.get("extra_headers") or {}
         out["extra_headers"] = {**openrouter_headers, **existing}
 
+    aiml_headers = llm._aiml_headers()
+    if aiml_headers:
+        existing = out.get("extra_headers") or {}
+        out["extra_headers"] = {**aiml_headers, **existing}
+
     return out
 
 
diff --git a/tests/sdk/llm/test_chat_options.py b/tests/sdk/llm/test_chat_options.py
index 7b8462ad74..0cbbe9ee08 100644
--- a/tests/sdk/llm/test_chat_options.py
+++ b/tests/sdk/llm/test_chat_options.py
@@ -29,6 +29,8 @@ class DummyLLM:
     _call_context: LLMCallContext = field(default_factory=LLMCallContext)
     openrouter_site_url: str = ""
     openrouter_app_name: str = ""
+    aimlapi_partner_id: str = ""
+    is_aiml_provider: bool = False
 
     def _openrouter_headers(self) -> dict[str, str]:
         headers: dict[str, str] = {}
@@ -38,6 +40,15 @@ def _openrouter_headers(self) -> dict[str, str]:
             headers["X-Title"] = self.openrouter_app_name
         return headers
 
+    def _aiml_headers(self) -> dict[str, str]:
+        if not self.is_aiml_provider:
+            return {}
+        headers: dict[str, str] = {}
+        if self.aimlapi_partner_id:
+            headers["X-AIMLAPI-Partner-ID"] = self.aimlapi_partner_id
+            headers["X-AIMLAPI-Source"] = "agent"
+        return headers
+
     def _model_name_for_capabilities(self) -> str:
         return self.model_canonical_name or self.model
 
@@ -390,3 +401,28 @@ def test_chat_options_omits_openrouter_headers_when_unset():
     llm = DummyLLM(model="gpt-4o")
     out = select_chat_options(llm, user_kwargs={}, has_tools=False)
     assert "extra_headers" not in out
+
+
+def test_chat_options_injects_aimlapi_partner_headers_for_aiml_provider():
+    """AIMLAPI partner attribution must flow per-call when routed via aiml."""
+    llm = DummyLLM(
+        model="aiml/anthropic/claude-opus-5",
+        is_aiml_provider=True,
+        aimlapi_partner_id="part_uDVajKg3xPLrOdNdQetOtoGA",
+    )
+    out = select_chat_options(llm, user_kwargs={}, has_tools=False)
+    assert out["extra_headers"]["X-AIMLAPI-Partner-ID"] == (
+        "part_uDVajKg3xPLrOdNdQetOtoGA"
+    )
+    assert out["extra_headers"]["X-AIMLAPI-Source"] == "agent"
+
+
+def test_chat_options_omits_aimlapi_headers_for_non_aiml_provider():
+    """The partner id must not leak onto unrelated providers as a stray header."""
+    llm = DummyLLM(
+        model="anthropic/claude-opus-5",
+        is_aiml_provider=False,
+        aimlapi_partner_id="part_uDVajKg3xPLrOdNdQetOtoGA",
+    )
+    out = select_chat_options(llm, user_kwargs={}, has_tools=False)
+    assert "extra_headers" not in out
diff --git a/tests/sdk/llm/test_llm.py b/tests/sdk/llm/test_llm.py
index f0c805ed21..1a27ea33cb 100644
--- a/tests/sdk/llm/test_llm.py
+++ b/tests/sdk/llm/test_llm.py
@@ -1910,4 +1910,27 @@ def test_max_output_tokens_not_capped_when_below_context_window(
     assert llm.effective_max_output_tokens == 8192
 
 
+def test_aiml_headers_present_for_aiml_provider():
+    """AIMLAPI partner attribution is built for a model routed via ``aiml``."""
+    llm = LLM(
+        model="aiml/anthropic/claude-opus-5",
+        api_key=SecretStr("test-key"),
+        usage_id="test-llm",
+    )
+    assert llm._aiml_headers() == {
+        "X-AIMLAPI-Partner-ID": "part_uDVajKg3xPLrOdNdQetOtoGA",
+        "X-AIMLAPI-Source": "agent",
+    }
+
+
+def test_aiml_headers_empty_for_non_aiml_provider():
+    """The partner id must not leak onto an unrelated provider's request."""
+    llm = LLM(
+        model="anthropic/claude-opus-5",
+        api_key=SecretStr("test-key"),
+        usage_id="test-llm",
+    )
+    assert llm._aiml_headers() == {}
+
+
 # LLM Registry Tests