diff --git a/proposals/cli/wit-0.3.0-draft/deps.lock b/proposals/cli/wit-0.3.0-draft/deps.lock
index 7d4bde4e..c6708067 100644
--- a/proposals/cli/wit-0.3.0-draft/deps.lock
+++ b/proposals/cli/wit-0.3.0-draft/deps.lock
@@ -5,15 +5,15 @@ sha512 = "f08a2828b88fc6ddea935af584531c484ad4a7a5f30340265e11e91b2bfe0f81e74a66
 
 [filesystem]
 path = "../../filesystem/wit-0.3.0-draft"
-sha256 = "184861e98785957311bfaab242cdf9e66a9ecca11fe2c493b840c461b2361088"
-sha512 = "50fa8801fc0a2c1ecfa3cea52af57836f98a12bb0a264439c13bbdcc0e269b3b37ade38b903d6ce10594d1f585d02ef993f3f769c4cddeebdfc00bf93734ed25"
+sha256 = "8808ea3adfbc1a025d649b82ddf4f38232ca4377100cfe671d80d5ee37fa3147"
+sha512 = "19f4eb8fa62e96ba37b3ea231af6a3bc396c28f82935018a3322441321936b34fb0e44360b378145fcb681d9fea810745969d8baab02ae6017be1784be8abe45"
 
 [random]
 path = "../../random/wit-0.3.0-draft"
-sha256 = "5794796c909d6656fcbae6bed28265210ca57308a624119ac0a472326a75aa8f"
-sha512 = "812ce57aa13ff3128779d41f4dad50714365e4f9cfd2e1b13458a885fa65da05e409f145deefa25c4a82e0e301a41e2e6572705b35752dc33908d565a73a2e9c"
+sha256 = "2d54fe2815781a7462f3540b0959842b7e15d9fe8530c2b961b35451b6922670"
+sha512 = "ac1a04d180f8aa11ac82529a0de7ff01c8d51d10424806aefe1c1d52ea9ade9911eaee2b3f7d9c23f4b3bfdff469af6482f4a9e5b800c465b9fb7b73ccc635c7"
 
 [sockets]
 path = "../../sockets/wit-0.3.0-draft"
-sha256 = "985821e86f2643d90b7a100420a44a5a60a6838adcf76fdb90a66255e3926dde"
-sha512 = "9ba1e9456c0dc02800ba738acd382a4113103bed72127396546c5f0ad3d38dd5c8e077443bd508b15f86f6095706907e9cb258cccab37c273b4c597a238987e7"
+sha256 = "5e7010b31fc80b5484cdcad7bfaae9dbb2134d3debfa6a90c69c30ec8cf7d55e"
+sha512 = "3863bd53d4ef1815f0f0f48d4032e3232322a3dbfa875eb573df2940264aacfe55d672886323406e5942ffc38ed5ad7dce91fcff3ff1e2e072773bb6dd9c7cd1"
diff --git a/proposals/http/wit-0.3.0-draft/deps.lock b/proposals/http/wit-0.3.0-draft/deps.lock
index e8f05aec..11113573 100644
--- a/proposals/http/wit-0.3.0-draft/deps.lock
+++ b/proposals/http/wit-0.3.0-draft/deps.lock
@@ -10,13 +10,13 @@ sha256 = "888647625fec3eaaf276cb884e426bc32bfa79ced22955f10eb239df74c8550c"
 sha512 = "f08a2828b88fc6ddea935af584531c484ad4a7a5f30340265e11e91b2bfe0f81e74a660a512f72e5197d60278feccc00534833ebd73868e801859dd31a61bdbb"
 
 [filesystem]
-sha256 = "184861e98785957311bfaab242cdf9e66a9ecca11fe2c493b840c461b2361088"
-sha512 = "50fa8801fc0a2c1ecfa3cea52af57836f98a12bb0a264439c13bbdcc0e269b3b37ade38b903d6ce10594d1f585d02ef993f3f769c4cddeebdfc00bf93734ed25"
+sha256 = "8808ea3adfbc1a025d649b82ddf4f38232ca4377100cfe671d80d5ee37fa3147"
+sha512 = "19f4eb8fa62e96ba37b3ea231af6a3bc396c28f82935018a3322441321936b34fb0e44360b378145fcb681d9fea810745969d8baab02ae6017be1784be8abe45"
 
 [random]
-sha256 = "5794796c909d6656fcbae6bed28265210ca57308a624119ac0a472326a75aa8f"
-sha512 = "812ce57aa13ff3128779d41f4dad50714365e4f9cfd2e1b13458a885fa65da05e409f145deefa25c4a82e0e301a41e2e6572705b35752dc33908d565a73a2e9c"
+sha256 = "2d54fe2815781a7462f3540b0959842b7e15d9fe8530c2b961b35451b6922670"
+sha512 = "ac1a04d180f8aa11ac82529a0de7ff01c8d51d10424806aefe1c1d52ea9ade9911eaee2b3f7d9c23f4b3bfdff469af6482f4a9e5b800c465b9fb7b73ccc635c7"
 
 [sockets]
-sha256 = "985821e86f2643d90b7a100420a44a5a60a6838adcf76fdb90a66255e3926dde"
-sha512 = "9ba1e9456c0dc02800ba738acd382a4113103bed72127396546c5f0ad3d38dd5c8e077443bd508b15f86f6095706907e9cb258cccab37c273b4c597a238987e7"
+sha256 = "5e7010b31fc80b5484cdcad7bfaae9dbb2134d3debfa6a90c69c30ec8cf7d55e"
+sha512 = "3863bd53d4ef1815f0f0f48d4032e3232322a3dbfa875eb573df2940264aacfe55d672886323406e5942ffc38ed5ad7dce91fcff3ff1e2e072773bb6dd9c7cd1"
diff --git a/proposals/http/wit-0.3.0-draft/types.wit b/proposals/http/wit-0.3.0-draft/types.wit
index 22f907d9..0d208fce 100644
--- a/proposals/http/wit-0.3.0-draft/types.wit
+++ b/proposals/http/wit-0.3.0-draft/types.wit
@@ -116,6 +116,20 @@ interface types {
     /// This error indicates that the operation on the `fields` was not
     /// permitted because the fields are immutable.
     immutable,
+
+    /// This error indicates that the operation would exceed an
+    /// implementation-defined limit on field sizes. This may apply to
+    /// an individual `field-value`, a single `field-name` plus all its
+    /// values, or the total aggregate size of all fields.
+    size-exceeded,
+
+    /// This is a catch-all error for anything that doesn't fit cleanly into a
+    /// more specific case. Implementations can use this to extend the error
+    /// type without breaking existing code. It also includes an optional
+    /// string for an unstructured description of the error. Users should not
+    /// depend on the string for diagnosing errors, as it's not required to be
+    /// consistent between implementations.
+    other(option<string>),
   }
 
   /// This type enumerates the different kinds of errors that may occur when
@@ -128,6 +142,14 @@ interface types {
     /// Indicates that the operation on the `request-options` was not permitted
     /// because it is immutable.
     immutable,
+
+    /// This is a catch-all error for anything that doesn't fit cleanly into a
+    /// more specific case. Implementations can use this to extend the error
+    /// type without breaking existing code. It also includes an optional
+    /// string for an unstructured description of the error. Users should not
+    /// depend on the string for diagnosing errors, as it's not required to be
+    /// consistent between implementations.
+    other(option<string>),
   }
 
   /// Field names are always strings.
@@ -158,6 +180,10 @@ interface types {
   /// original casing used to construct or mutate the `fields` resource. The `fields`
   /// resource should use that original casing when serializing the fields for
   /// transport or when returning them from a method.
+  ///
+  /// Implementations may impose limits on individual field values and on total
+  /// aggregate field section size. Operations that would exceed these limits
+  /// fail with `header-error.size-exceeded`
   @since(version = 0.3.0-rc-2026-02-09)
   resource fields {
 
@@ -180,7 +206,8 @@ interface types {
     /// well-formed, so they are represented as a raw list of bytes.
     ///
     /// An error result will be returned if any header or value was
-    /// syntactically invalid, or if a header was forbidden.
+    /// syntactically invalid, if a header was forbidden, or if the
+    /// entries would exceed an implementation size limit.
     from-list: static func(
       entries: list<tuple<field-name,field-value>>
     ) -> result<fields, header-error>;
@@ -199,6 +226,9 @@ interface types {
     /// name, if they have been set.
     ///
     /// Fails with `header-error.immutable` if the `fields` are immutable.
+    ///
+    /// Fails with `header-error.size-exceeded` if the name or values would
+    /// exceed an implementation-defined size limit.
     set: func(name: field-name, value: list<field-value>) -> result<_, header-error>;
 
     /// Delete all values for a name. Does nothing if no values for the name
@@ -219,6 +249,9 @@ interface types {
     /// values for that name.
     ///
     /// Fails with `header-error.immutable` if the `fields` are immutable.
+    ///
+    /// Fails with `header-error.size-exceeded` if the value would exceed
+    /// an implementation-defined size limit.
     append: func(name: field-name, value: field-value) -> result<_, header-error>;
 
     /// Retrieve the full set of names and values in the Fields. Like the