From b030baab59f4fc0429ddc6a03c24c085aacc49b8 Mon Sep 17 00:00:00 2001
From: Chay Nabors <nabochay@amazon.com>
Date: Thu, 2 Apr 2026 15:31:40 -0400
Subject: [PATCH] Add wasi:http support

---
 tests/component/test_linker.py | 30 +++++++++++++++++++++++++++++-
 wasmtime/_bindings.py          | 12 ++++++++++++
 wasmtime/_store.py             |  9 +++++++++
 wasmtime/component/_linker.py  | 12 ++++++++++++
 4 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/tests/component/test_linker.py b/tests/component/test_linker.py
index df0ac093..a424bc18 100644
--- a/tests/component/test_linker.py
+++ b/tests/component/test_linker.py
@@ -1,6 +1,6 @@
 import unittest
 
-from wasmtime import Engine, WasmtimeError, Module, Store
+from wasmtime import Engine, WasiConfig, WasmtimeError, Module, Store
 from wasmtime.component import Linker, Component, LinkerInstance
 
 
@@ -143,6 +143,34 @@ def test_shadow_func(self):
         with linker.root() as l:
             l.add_func('x', lambda: None)
 
+    def test_add_wasi_http(self):
+        engine = Engine()
+        linker = Linker(engine)
+        linker.add_wasip2()
+        linker.add_wasi_http()
+
+        with linker.root():
+            with self.assertRaises(WasmtimeError):
+                linker.add_wasi_http()
+
+        linker.close()
+
+        with Linker(engine) as l2:
+            l2.add_wasip2()
+            l2.add_wasi_http()
+            with self.assertRaises(WasmtimeError):
+                l2.add_wasi_http()
+            l2.allow_shadowing = True
+            l2.add_wasi_http()
+
+    def test_set_wasi_http(self):
+        engine = Engine()
+        store = Store(engine)
+        wasi = WasiConfig()
+        wasi.inherit_stdout()
+        store.set_wasi(wasi)
+        store.set_wasi_http()
+
     def test_define_unknown_imports_as_traps(self):
         engine = Engine()
         store = Store(engine)
diff --git a/wasmtime/_bindings.py b/wasmtime/_bindings.py
index f74b8a01..8b896303 100644
--- a/wasmtime/_bindings.py
+++ b/wasmtime/_bindings.py
@@ -2694,6 +2694,12 @@ def wasmtime_context_get_fuel(context: Any, fuel: Any) -> ctypes._Pointer:
 def wasmtime_context_set_wasi(context: Any, wasi: Any) -> ctypes._Pointer:
     return _wasmtime_context_set_wasi(context, wasi)  # type: ignore
 
+_wasmtime_context_set_wasi_http = dll.wasmtime_context_set_wasi_http
+_wasmtime_context_set_wasi_http.restype = None
+_wasmtime_context_set_wasi_http.argtypes = [ctypes.POINTER(wasmtime_context_t)]
+def wasmtime_context_set_wasi_http(context: Any) -> None:
+    return _wasmtime_context_set_wasi_http(context)  # type: ignore
+
 _wasmtime_context_set_epoch_deadline = dll.wasmtime_context_set_epoch_deadline
 _wasmtime_context_set_epoch_deadline.restype = None
 _wasmtime_context_set_epoch_deadline.argtypes = [ctypes.POINTER(wasmtime_context_t), ctypes.c_uint64]
@@ -4751,6 +4757,12 @@ def wasmtime_component_linker_instance_add_func(linker_instance: Any, name: Any,
 def wasmtime_component_linker_add_wasip2(linker: Any) -> ctypes._Pointer:
     return _wasmtime_component_linker_add_wasip2(linker)  # type: ignore
 
+_wasmtime_component_linker_add_wasi_http = dll.wasmtime_component_linker_add_wasi_http
+_wasmtime_component_linker_add_wasi_http.restype = ctypes.POINTER(wasmtime_error_t)
+_wasmtime_component_linker_add_wasi_http.argtypes = [ctypes.POINTER(wasmtime_component_linker_t)]
+def wasmtime_component_linker_add_wasi_http(linker: Any) -> ctypes._Pointer:
+    return _wasmtime_component_linker_add_wasi_http(linker)  # type: ignore
+
 wasmtime_component_resource_destructor_t = ctypes.CFUNCTYPE(ctypes.c_size_t, ctypes.c_void_p, ctypes.POINTER(wasmtime_context_t), ctypes.c_uint32)
 
 _wasmtime_component_linker_instance_add_resource = dll.wasmtime_component_linker_instance_add_resource
diff --git a/wasmtime/_store.py b/wasmtime/_store.py
index 9467f062..bd3a6c2a 100644
--- a/wasmtime/_store.py
+++ b/wasmtime/_store.py
@@ -97,6 +97,15 @@ def set_wasi(self, wasi: "WasiConfig") -> None:
         if error:
             raise WasmtimeError._from_ptr(error)
 
+    def set_wasi_http(self) -> None:
+        """
+        Initializes the WASI HTTP context for this store.
+
+        Must be called before instantiating a component that uses `wasi:http`.
+        Requires WASI to be configured first via `set_wasi()`.
+        """
+        ffi.wasmtime_context_set_wasi_http(self._context())
+
     def set_epoch_deadline(self, ticks_after_current: int) -> None:
         """
         Configures the relative epoch deadline, after the current engine's
diff --git a/wasmtime/component/_linker.py b/wasmtime/component/_linker.py
index fa1acd6d..6ce56ddc 100644
--- a/wasmtime/component/_linker.py
+++ b/wasmtime/component/_linker.py
@@ -73,6 +73,18 @@ def add_wasip2(self) -> None:
         if err:
             raise WasmtimeError._from_ptr(err)
 
+    def add_wasi_http(self) -> None:
+        """
+        Adds the WASI HTTP API definitions to this linker.
+
+        This adds `wasi:http/types` and `wasi:http/outgoing-handler`.
+        Requires WASIp2 to be added first via `add_wasip2()`.
+        """
+        self._assert_not_locked()
+        err = ffi.wasmtime_component_linker_add_wasi_http(self.ptr())
+        if err:
+            raise WasmtimeError._from_ptr(err)
+
     def instantiate(self, store: Storelike, component: Component) -> Instance:
         """
         Instantiates the given component using this linker within the provided