diff --git a/cli/src/commands/compatibility.rs b/cli/src/commands/compatibility.rs
index 99730334e3..614af7f08b 100644
--- a/cli/src/commands/compatibility.rs
+++ b/cli/src/commands/compatibility.rs
@@ -77,7 +77,7 @@ async fn handle_pallet_metadata(
                 compatibility
                     .pallet_present
                     .entry(hex_hash)
-                    .or_insert_with(Vec::new)
+                    .or_default()
                     .push(node.to_string());
             }
             None => {
@@ -110,7 +110,7 @@ async fn handle_full_metadata(
 
         compatibility_map
             .entry(hex_hash)
-            .or_insert_with(Vec::new)
+            .or_default()
             .push(node.to_string());
     }
 
diff --git a/cli/src/commands/diff.rs b/cli/src/commands/diff.rs
index 9200e85209..50439ebe93 100644
--- a/cli/src/commands/diff.rs
+++ b/cli/src/commands/diff.rs
@@ -13,7 +13,6 @@ use scale_info::Variant;
 
 use subxt_metadata::{
     ConstantMetadata, Metadata, PalletMetadata, RuntimeApiMetadata, StorageEntryMetadata,
-    StorageEntryType,
 };
 
 /// Explore the differences between two nodes
@@ -220,40 +219,34 @@ impl StorageEntryDiff {
         metadata_1: &Metadata,
         metadata_2: &Metadata,
     ) -> Self {
-        let value_1_ty_id = match storage_entry_1.entry_type() {
-            StorageEntryType::Plain(value_ty) | StorageEntryType::Map { value_ty, .. } => value_ty,
-        };
+        let value_1_ty_id = storage_entry_1.entry_type().value_ty();
         let value_1_hash = metadata_1
-            .type_hash(*value_1_ty_id)
+            .type_hash(value_1_ty_id)
             .expect("type should be present");
-        let value_2_ty_id = match storage_entry_2.entry_type() {
-            StorageEntryType::Plain(value_ty) | StorageEntryType::Map { value_ty, .. } => value_ty,
-        };
+        let value_2_ty_id = storage_entry_2.entry_type().value_ty();
         let value_2_hash = metadata_1
-            .type_hash(*value_2_ty_id)
+            .type_hash(value_2_ty_id)
             .expect("type should be present");
         let value_different = value_1_hash != value_2_hash;
 
-        let key_1_hash = match storage_entry_1.entry_type() {
-            StorageEntryType::Plain(_) => None,
-            StorageEntryType::Map { key_ty, .. } => Some(*key_ty),
-        }
-        .map(|key_ty| {
-            metadata_1
-                .type_hash(key_ty)
-                .expect("type should be present")
-        })
-        .unwrap_or_default();
-        let key_2_hash = match storage_entry_2.entry_type() {
-            StorageEntryType::Plain(_) => None,
-            StorageEntryType::Map { key_ty, .. } => Some(*key_ty),
-        }
-        .map(|key_ty| {
-            metadata_2
-                .type_hash(key_ty)
-                .expect("type should be present")
-        })
-        .unwrap_or_default();
+        let key_1_hash = storage_entry_1
+            .entry_type()
+            .key_ty()
+            .map(|key_ty| {
+                metadata_1
+                    .type_hash(key_ty)
+                    .expect("type should be present")
+            })
+            .unwrap_or_default();
+        let key_2_hash = storage_entry_2
+            .entry_type()
+            .key_ty()
+            .map(|key_ty| {
+                metadata_2
+                    .type_hash(key_ty)
+                    .expect("type should be present")
+            })
+            .unwrap_or_default();
         let key_different = key_1_hash != key_2_hash;
 
         StorageEntryDiff {
diff --git a/codegen/Cargo.toml b/codegen/Cargo.toml
index 18609661fb..a336f7fa7c 100644
--- a/codegen/Cargo.toml
+++ b/codegen/Cargo.toml
@@ -12,21 +12,25 @@ documentation = "https://docs.rs/subxt-codegen"
 homepage.workspace = true
 description = "Generate an API for interacting with a substrate node from FRAME metadata"
 
+[features]
+default = ["fetch-metadata"]
+fetch-metadata = ["dep:jsonrpsee", "dep:tokio", "dep:frame-metadata"]
+
 [dependencies]
 codec = { package = "parity-scale-codec", workspace = true, features = ["derive"] }
-frame-metadata = { workspace = true }
+frame-metadata = { workspace = true, optional = true }
 heck = { workspace = true }
 proc-macro2 = { workspace = true }
 quote = { workspace = true }
 syn = { workspace = true }
 scale-info = { workspace = true }
 subxt-metadata = { workspace = true }
-jsonrpsee = { workspace = true, features = ["async-client", "client-ws-transport-native-tls", "http-client"] }
+jsonrpsee = { workspace = true, features = ["async-client", "client-ws-transport-native-tls", "http-client"], optional = true }
 hex = { workspace = true }
-tokio = { workspace = true, features = ["rt-multi-thread"] }
+tokio = { workspace = true, features = ["rt-multi-thread"], optional = true }
 thiserror = { workspace = true }
 
 [dev-dependencies]
 bitvec = { workspace = true }
 scale-info = { workspace = true, features = ["bit-vec"] }
-pretty_assertions = { workspace = true }
+pretty_assertions = { workspace = true }
\ No newline at end of file
diff --git a/codegen/src/api/mod.rs b/codegen/src/api/mod.rs
index 7802ba7ea9..1d1897e3d2 100644
--- a/codegen/src/api/mod.rs
+++ b/codegen/src/api/mod.rs
@@ -20,14 +20,14 @@ use crate::error::CodegenError;
 use crate::{
     ir,
     types::{CompositeDef, CompositeDefFields, TypeGenerator, TypeSubstitutes},
-    utils::{fetch_metadata_bytes_blocking, MetadataVersion, Url},
     CratePath,
 };
+
 use codec::Decode;
 use heck::ToSnakeCase as _;
 use proc_macro2::TokenStream as TokenStream2;
 use quote::{format_ident, quote};
-use std::{collections::HashMap, fs, io::Read, path, string::ToString};
+use std::{fs, io::Read, path, string::ToString};
 use syn::parse_quote;
 
 /// Generate the runtime API for interacting with a substrate runtime.
@@ -146,7 +146,10 @@ impl GenerateRuntimeApi {
     /// # Warning
     ///
     /// Not recommended to be used in production environments.
-    pub fn generate_from_url(self, url: Url) -> Result<TokenStream2, CodegenError> {
+    #[cfg(feature = "fetch-metadata")]
+    pub fn generate_from_url(self, url: crate::utils::Url) -> Result<TokenStream2, CodegenError> {
+        use crate::utils::{fetch_metadata_bytes_blocking, MetadataVersion, Url};
+
         fn fetch_metadata(url: Url, version: MetadataVersion) -> Result<Metadata, CodegenError> {
             let bytes = fetch_metadata_bytes_blocking(url, version)?;
             Ok(Metadata::decode(&mut &bytes[..])?)
@@ -225,49 +228,10 @@ impl RuntimeGenerator {
     ///
     /// Supported versions: v14 and v15.
     pub fn new(mut metadata: Metadata) -> Self {
-        Self::ensure_unique_type_paths(&mut metadata);
+        metadata.ensure_unique_type_paths();
         RuntimeGenerator { metadata }
     }
 
-    /// Ensure that every unique type we'll be generating or referring to also has a
-    /// unique path, so that types with matching paths don't end up overwriting each other
-    /// in the codegen. We ignore any types with generics; Subxt actually endeavours to
-    /// de-duplicate those into single types with a generic.
-    fn ensure_unique_type_paths(metadata: &mut Metadata) {
-        let mut visited_path_counts = HashMap::<Vec<String>, usize>::new();
-        for ty in metadata.types_mut().types.iter_mut() {
-            // Ignore types without a path (ie prelude types).
-            if ty.ty.path.namespace().is_empty() {
-                continue;
-            }
-
-            let has_valid_type_params = ty.ty.type_params.iter().any(|tp| tp.ty.is_some());
-
-            // Ignore types which have generic params that the type generation will use.
-            // Ordinarily we'd expect that any two types with identical paths must be parameterized
-            // in order to share the path. However scale-info doesn't understand all forms of generics
-            // properly I think (eg generics that have associated types that can differ), and so in
-            // those cases we need to fix the paths for Subxt to generate correct code.
-            if has_valid_type_params {
-                continue;
-            }
-
-            // Count how many times we've seen the same path already.
-            let visited_count = visited_path_counts
-                .entry(ty.ty.path.segments.clone())
-                .or_default();
-            *visited_count += 1;
-
-            // alter the type so that if it's been seen more than once, we append a number to
-            // its name to ensure that every unique type has a unique path, too.
-            if *visited_count > 1 {
-                if let Some(name) = ty.ty.path.segments.last_mut() {
-                    *name = format!("{name}{visited_count}");
-                }
-            }
-        }
-    }
-
     /// Generate the API for interacting with a Substrate runtime.
     ///
     /// # Arguments
diff --git a/codegen/src/api/storage.rs b/codegen/src/api/storage.rs
index 4101fd80e8..988679e7a9 100644
--- a/codegen/src/api/storage.rs
+++ b/codegen/src/api/storage.rs
@@ -96,10 +96,7 @@ fn generate_storage_entry_fns(
     };
 
     let snake_case_name = storage_entry.name().to_snake_case();
-    let storage_entry_ty = match storage_entry.entry_type() {
-        StorageEntryType::Plain(ty) => *ty,
-        StorageEntryType::Map { value_ty, .. } => *value_ty,
-    };
+    let storage_entry_ty = storage_entry.entry_type().value_ty();
     let storage_entry_value_ty = type_gen.resolve_type_path(storage_entry_ty);
     let docs = storage_entry.docs();
     let docs = should_gen_docs
diff --git a/codegen/src/error.rs b/codegen/src/error.rs
index f293df2ee6..60437f5de7 100644
--- a/codegen/src/error.rs
+++ b/codegen/src/error.rs
@@ -8,6 +8,7 @@ use proc_macro2::{Span, TokenStream as TokenStream2};
 
 /// Error returned when the Codegen cannot generate the runtime API.
 #[derive(Debug, thiserror::Error)]
+#[non_exhaustive]
 pub enum CodegenError {
     /// The given metadata type could not be found.
     #[error("Could not find type with ID {0} in the type registry; please raise a support issue.")]
@@ -82,11 +83,13 @@ impl CodegenError {
 
 /// Error attempting to load metadata.
 #[derive(Debug, thiserror::Error)]
+#[non_exhaustive]
 pub enum FetchMetadataError {
     #[error("Cannot decode hex value: {0}")]
     DecodeError(#[from] hex::FromHexError),
     #[error("Cannot scale encode/decode value: {0}")]
     CodecError(#[from] codec::Error),
+    #[cfg(feature = "fetch-metadata")]
     #[error("Request error: {0}")]
     RequestError(#[from] jsonrpsee::core::Error),
     #[error("'{0}' not supported, supported URI schemes are http, https, ws or wss.")]
@@ -97,6 +100,7 @@ pub enum FetchMetadataError {
 
 /// Error attempting to do type substitution.
 #[derive(Debug, thiserror::Error)]
+#[non_exhaustive]
 pub enum TypeSubstitutionError {
     /// Substitute "to" type must be an absolute path.
     #[error("`substitute_type(with = <path>)` must be a path prefixed with 'crate::' or '::'")]
diff --git a/codegen/src/lib.rs b/codegen/src/lib.rs
index be2e27e0d2..5af5a244b9 100644
--- a/codegen/src/lib.rs
+++ b/codegen/src/lib.rs
@@ -50,10 +50,17 @@ mod error;
 mod ir;
 mod types;
 
+#[cfg(feature = "fetch-metadata")]
 pub mod utils;
 
+#[cfg(all(feature = "web", feature = "fetch-metadata"))]
+compile_error!("subxt-codegen: the features 'web' and 'fetch_metadata' cannot be used together.");
+
 pub use self::{
     api::{GenerateRuntimeApi, RuntimeGenerator},
     error::{CodegenError, TypeSubstitutionError},
-    types::{CratePath, Derives, DerivesRegistry, Module, TypeGenerator, TypeSubstitutes},
+    types::{
+        CratePath, Derives, DerivesRegistry, Module, TypeDefGen, TypeDefParameters, TypeGenerator,
+        TypeSubstitutes,
+    },
 };
diff --git a/codegen/src/types/mod.rs b/codegen/src/types/mod.rs
index 2e8d1611be..f565fb0460 100644
--- a/codegen/src/types/mod.rs
+++ b/codegen/src/types/mod.rs
@@ -262,6 +262,11 @@ impl<'a> TypeGenerator<'a> {
         self.derives.default_derives()
     }
 
+    /// Returns the type registry.
+    pub fn types(&self) -> &PortableRegistry {
+        self.type_registry
+    }
+
     /// Returns the derives to be applied to a generated type.
     pub fn type_derives(&self, ty: &Type<PortableForm>) -> Result<Derives, CodegenError> {
         let joined_path = ty.path.segments.join("::");
diff --git a/codegen/src/types/type_def.rs b/codegen/src/types/type_def.rs
index 25fa02556a..57470abf7f 100644
--- a/codegen/src/types/type_def.rs
+++ b/codegen/src/types/type_def.rs
@@ -118,6 +118,11 @@ impl TypeDefGen {
             ty_docs,
         })
     }
+
+    /// are there unused type params?
+    pub fn has_unused_type_params(&self) -> bool {
+        self.type_params.has_unused_type_params()
+    }
 }
 
 impl quote::ToTokens for TypeDefGen {
diff --git a/codegen/src/types/type_def_params.rs b/codegen/src/types/type_def_params.rs
index 15dc5b6bc2..155029fdd4 100644
--- a/codegen/src/types/type_def_params.rs
+++ b/codegen/src/types/type_def_params.rs
@@ -60,6 +60,11 @@ impl TypeDefParameters {
     pub fn params(&self) -> &[TypeParameter] {
         &self.params
     }
+
+    /// Returns true if there are any unused type params
+    pub fn has_unused_type_params(&self) -> bool {
+        !self.unused.is_empty()
+    }
 }
 
 impl quote::ToTokens for TypeDefParameters {
diff --git a/examples/wasm-example/Cargo.lock b/examples/wasm-example/Cargo.lock
index 174decfb19..8a8a3af72d 100644
--- a/examples/wasm-example/Cargo.lock
+++ b/examples/wasm-example/Cargo.lock
@@ -107,9 +107,9 @@ dependencies = [
 
 [[package]]
 name = "async-trait"
-version = "0.1.72"
+version = "0.1.73"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc6dde6e4ed435a4c1ee4e73592f5ba9da2151af10076cc04858746af9352d09"
+checksum = "bc00ceb34980c03614e35a3a4e218276a0a824e911d07651cd0d858a51e8c0f0"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -859,7 +859,7 @@ dependencies = [
  "gloo-render",
  "gloo-storage",
  "gloo-timers",
- "gloo-utils",
+ "gloo-utils 0.1.7",
  "gloo-worker",
 ]
 
@@ -869,7 +869,7 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "82b7ce3c05debe147233596904981848862b068862e9ec3e34be446077190d3f"
 dependencies = [
- "gloo-utils",
+ "gloo-utils 0.1.7",
  "js-sys",
  "serde",
  "wasm-bindgen",
@@ -916,7 +916,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ddfd137a4b629e72b8c949ec56c71ea9bd5491cc66358a0a7787e94875feec71"
 dependencies = [
  "gloo-events",
- "gloo-utils",
+ "gloo-utils 0.1.7",
  "serde",
  "serde-wasm-bindgen",
  "serde_urlencoded",
@@ -927,14 +927,15 @@ dependencies = [
 
 [[package]]
 name = "gloo-net"
-version = "0.2.6"
+version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9902a044653b26b99f7e3693a42f171312d9be8b26b5697bd1e43ad1f8a35e10"
+checksum = "3000ef231a67d5bfee6b35f2c0f6f5c8d45b3381ef5bbbea603690ec4e539762"
 dependencies = [
  "futures-channel",
  "futures-core",
  "futures-sink",
- "gloo-utils",
+ "gloo-utils 0.1.7",
+ "http",
  "js-sys",
  "pin-project",
  "serde",
@@ -947,14 +948,14 @@ dependencies = [
 
 [[package]]
 name = "gloo-net"
-version = "0.3.0"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3000ef231a67d5bfee6b35f2c0f6f5c8d45b3381ef5bbbea603690ec4e539762"
+checksum = "8ac9e8288ae2c632fa9f8657ac70bfe38a1530f345282d7ba66a1f70b72b7dc4"
 dependencies = [
  "futures-channel",
  "futures-core",
  "futures-sink",
- "gloo-utils",
+ "gloo-utils 0.2.0",
  "http",
  "js-sys",
  "pin-project",
@@ -982,7 +983,7 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5d6ab60bf5dbfd6f0ed1f7843da31b41010515c745735c970e821945ca91e480"
 dependencies = [
- "gloo-utils",
+ "gloo-utils 0.1.7",
  "js-sys",
  "serde",
  "serde_json",
@@ -1016,6 +1017,19 @@ dependencies = [
  "web-sys",
 ]
 
+[[package]]
+name = "gloo-utils"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b5555354113b18c547c1d3a98fbf7fb32a9ff4f6fa112ce823a21641a0ba3aa"
+dependencies = [
+ "js-sys",
+ "serde",
+ "serde_json",
+ "wasm-bindgen",
+ "web-sys",
+]
+
 [[package]]
 name = "gloo-worker"
 version = "0.2.1"
@@ -1025,7 +1039,7 @@ dependencies = [
  "anymap2",
  "bincode",
  "gloo-console",
- "gloo-utils",
+ "gloo-utils 0.1.7",
  "js-sys",
  "serde",
  "wasm-bindgen",
@@ -1169,7 +1183,7 @@ dependencies = [
  "httpdate",
  "itoa",
  "pin-project-lite",
- "socket2",
+ "socket2 0.4.9",
  "tokio",
  "tower-service",
  "tracing",
@@ -1178,10 +1192,11 @@ dependencies = [
 
 [[package]]
 name = "hyper-rustls"
-version = "0.23.2"
+version = "0.24.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1788965e61b367cd03a62950836d5cd41560c3577d90e40e0819373194d1661c"
+checksum = "8d78e1e73ec14cf7375674f74d7dde185c8206fd9dea6fb6295e8a98098aaa97"
 dependencies = [
+ "futures-util",
  "http",
  "hyper",
  "log",
@@ -1189,7 +1204,6 @@ dependencies = [
  "rustls-native-certs",
  "tokio",
  "tokio-rustls",
- "webpki-roots",
 ]
 
 [[package]]
@@ -1198,6 +1212,16 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
 
+[[package]]
+name = "idna"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d20d6b07bfbc108882d88ed8e37d39636dcc260e15e30c45e6ba089610b917c"
+dependencies = [
+ "unicode-bidi",
+ "unicode-normalization",
+]
+
 [[package]]
 name = "impl-codec"
 version = "0.6.0"
@@ -1306,9 +1330,9 @@ dependencies = [
 
 [[package]]
 name = "jsonrpsee"
-version = "0.16.2"
+version = "0.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d291e3a5818a2384645fd9756362e6d89cf0541b0b916fa7702ea4a9833608e"
+checksum = "9ad9b31183a8bcbe843e32ca8554ad2936633548d95a7bb6a8e14c767dea6b05"
 dependencies = [
  "jsonrpsee-client-transport",
  "jsonrpsee-core",
@@ -1318,18 +1342,15 @@ dependencies = [
 
 [[package]]
 name = "jsonrpsee-client-transport"
-version = "0.16.2"
+version = "0.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "965de52763f2004bc91ac5bcec504192440f0b568a5d621c59d9dbd6f886c3fb"
+checksum = "97f2743cad51cc86b0dbfe316309eeb87a9d96a3d7f4dd7a99767c4b5f065335"
 dependencies = [
- "anyhow",
  "futures-channel",
- "futures-timer",
  "futures-util",
- "gloo-net 0.2.6",
+ "gloo-net 0.4.0",
  "http",
  "jsonrpsee-core",
- "jsonrpsee-types",
  "pin-project",
  "rustls-native-certs",
  "soketto",
@@ -1338,20 +1359,19 @@ dependencies = [
  "tokio-rustls",
  "tokio-util",
  "tracing",
- "webpki-roots",
+ "url",
 ]
 
 [[package]]
 name = "jsonrpsee-core"
-version = "0.16.2"
+version = "0.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4e70b4439a751a5de7dd5ed55eacff78ebf4ffe0fc009cb1ebb11417f5b536b"
+checksum = "35dc957af59ce98373bcdde0c1698060ca6c2d2e9ae357b459c7158b6df33330"
 dependencies = [
  "anyhow",
  "async-lock",
  "async-trait",
  "beef",
- "futures-channel",
  "futures-timer",
  "futures-util",
  "hyper",
@@ -1367,28 +1387,29 @@ dependencies = [
 
 [[package]]
 name = "jsonrpsee-http-client"
-version = "0.16.2"
+version = "0.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc345b0a43c6bc49b947ebeb936e886a419ee3d894421790c969cc56040542ad"
+checksum = "0dd865d0072764cb937b0110a92b5f53e995f7101cb346beca03d93a2dea79de"
 dependencies = [
  "async-trait",
  "hyper",
  "hyper-rustls",
  "jsonrpsee-core",
  "jsonrpsee-types",
- "rustc-hash",
  "serde",
  "serde_json",
  "thiserror",
  "tokio",
+ "tower",
  "tracing",
+ "url",
 ]
 
 [[package]]
 name = "jsonrpsee-types"
-version = "0.16.2"
+version = "0.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5bd522fe1ce3702fd94812965d7bb7a3364b1c9aba743944c5a00529aae80f8c"
+checksum = "fa9e25aec855b2a7d3ed90fded6c41e8c3fb72b63f071e1be3f0004eba19b625"
 dependencies = [
  "anyhow",
  "beef",
@@ -1709,9 +1730,9 @@ dependencies = [
 
 [[package]]
 name = "pin-project-lite"
-version = "0.2.10"
+version = "0.2.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c40d25201921e5ff0c862a505c6557ea88568a4e3ace775ab55e93f2f4f9d57"
+checksum = "8afb450f006bf6385ca15ef45d71d2288452bc3683ce2e2cacc0d18e4be60b58"
 
 [[package]]
 name = "pin-utils"
@@ -1824,9 +1845,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.66"
+version = "1.0.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18fb31db3f9bddb2ea821cde30a9f70117e3f119938b5ee630b7403aa6e2ead9"
+checksum = "3d433d9f1a3e8c1263d9456598b16fec66f4acc9a74dacffd35c7bb09b3a1328"
 dependencies = [
  "unicode-ident",
 ]
@@ -1850,9 +1871,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.32"
+version = "1.0.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50f3b39ccfb720540debaa0164757101c08ecb8d326b15358ce76a62c7e85965"
+checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
 dependencies = [
  "proc-macro2",
 ]
@@ -1949,14 +1970,14 @@ dependencies = [
 
 [[package]]
 name = "rustls"
-version = "0.20.8"
+version = "0.21.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fff78fc74d175294f4e83b28343315ffcfb114b156f0185e9741cb5570f50e2f"
+checksum = "cd8d6c9f025a446bc4d18ad9632e69aec8f287aa84499ee335599fabd20c3fd8"
 dependencies = [
  "log",
  "ring",
+ "rustls-webpki",
  "sct",
- "webpki",
 ]
 
 [[package]]
@@ -1980,6 +2001,16 @@ dependencies = [
  "base64 0.21.2",
 ]
 
+[[package]]
+name = "rustls-webpki"
+version = "0.101.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "45a27e3b59326c16e23d30aeb7a36a24cc0d29e71d68ff611cdfb4a01d013bed"
+dependencies = [
+ "ring",
+ "untrusted",
+]
+
 [[package]]
 name = "rustversion"
 version = "1.0.14"
@@ -2194,9 +2225,9 @@ checksum = "cd0b0ec5f1c1ca621c432a25813d8d60c88abe6d3e08a3eb9cf37d97a0fe3d73"
 
 [[package]]
 name = "serde"
-version = "1.0.181"
+version = "1.0.188"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d3e73c93c3240c0bda063c239298e633114c69a888c3e37ca8bb33f343e9890"
+checksum = "cf9e0fcba69a370eed61bcf2b728575f726b50b55cba78064753d708ddc7549e"
 dependencies = [
  "serde_derive",
 ]
@@ -2214,9 +2245,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.181"
+version = "1.0.188"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be02f6cb0cd3a5ec20bbcfbcbd749f57daddb1a0882dc2e46a6c236c90b977ed"
+checksum = "4eca7ac642d82aa35b60049a6eccb4be6be75e599bd2e9adb5f875a737654af2"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2225,9 +2256,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.104"
+version = "1.0.107"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "076066c5f1078eac5b722a31827a8832fe108bed65dfa75e233c89f8206e976c"
+checksum = "6b420ce6e3d8bd882e9b243c6eed35dbc9a6110c9769e74b584e0d68d1f20c65"
 dependencies = [
  "itoa",
  "ryu",
@@ -2416,6 +2447,16 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "socket2"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4031e820eb552adee9295814c0ced9e5cf38ddf1e8b7d566d6de8e2538ea989e"
+dependencies = [
+ "libc",
+ "windows-sys",
+]
+
 [[package]]
 name = "soketto"
 version = "0.7.1"
@@ -2492,13 +2533,13 @@ checksum = "734676eb262c623cec13c3155096e08d1f8f29adce39ba17948b18dad1e54142"
 name = "subxt"
 version = "0.31.0"
 dependencies = [
+ "async-trait",
  "base58",
  "blake2",
  "derivative",
  "either",
  "frame-metadata 16.0.0",
  "futures",
- "getrandom",
  "hex",
  "impl-serde",
  "jsonrpsee",
@@ -2612,9 +2653,9 @@ checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
 
 [[package]]
 name = "thiserror"
-version = "1.0.44"
+version = "1.0.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "611040a08a0439f8248d1990b111c95baa9c704c805fa1f62104b39655fd7f90"
+checksum = "9d6d7a740b8a666a7e828dd00da9c0dc290dff53154ea77ac109281de90589b7"
 dependencies = [
  "thiserror-impl",
 ]
@@ -2641,9 +2682,9 @@ dependencies = [
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.44"
+version = "1.0.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "090198534930841fab3a5d1bb637cde49e339654e606195f8d9c76eeb081dc96"
+checksum = "49922ecae66cc8a249b77e68d1d0623c1b2c514f0060c27cdc68bd62a1219d35"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2676,18 +2717,17 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
 [[package]]
 name = "tokio"
-version = "1.29.1"
+version = "1.32.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "532826ff75199d5833b9d2c5fe410f29235e25704ee5f0ef599fb51c21f4a4da"
+checksum = "17ed6077ed6cd6c74735e21f37eb16dc3935f96878b1fe961074089cc80893f9"
 dependencies = [
- "autocfg",
  "backtrace",
  "bytes",
  "libc",
  "mio",
  "num_cpus",
  "pin-project-lite",
- "socket2",
+ "socket2 0.5.4",
  "tokio-macros",
  "windows-sys",
 ]
@@ -2705,13 +2745,12 @@ dependencies = [
 
 [[package]]
 name = "tokio-rustls"
-version = "0.23.4"
+version = "0.24.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c43ee83903113e03984cb9e5cebe6c04a5116269e900e3ddba8f068a62adda59"
+checksum = "c28327cf380ac148141087fbfb9de9d7bd4e84ab5d2c28fbc911d753de8a7081"
 dependencies = [
  "rustls",
  "tokio",
- "webpki",
 ]
 
 [[package]]
@@ -2757,6 +2796,27 @@ dependencies = [
  "winnow",
 ]
 
+[[package]]
+name = "tower"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8fa9be0de6cf49e536ce1851f987bd21a43b771b09473c3549a6c853db37c1c"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "pin-project",
+ "pin-project-lite",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "tower-layer"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c20c8dbed6283a09604c3e69b4b7eeb54e298b8a600d4d5ecb5ad39de609f1d0"
+
 [[package]]
 name = "tower-service"
 version = "0.3.2"
@@ -2770,6 +2830,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ce8c33a8d48bd45d624a6e523445fd21ec13d3653cd51f681abf67418f54eb8"
 dependencies = [
  "cfg-if",
+ "log",
  "pin-project-lite",
  "tracing-attributes",
  "tracing-core",
@@ -2809,7 +2870,6 @@ checksum = "97fee6b57c6a41524a810daee9286c02d7752c4253064d0b05472833a438f675"
 dependencies = [
  "cfg-if",
  "digest 0.10.7",
- "rand",
  "static_assertions",
 ]
 
@@ -2831,12 +2891,27 @@ dependencies = [
  "static_assertions",
 ]
 
+[[package]]
+name = "unicode-bidi"
+version = "0.3.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "92888ba5573ff080736b3648696b70cafad7d250551175acbaa4e0385b3e1460"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "301abaae475aa91687eb82514b328ab47a211a533026cb25fc3e519b86adfc3c"
 
+[[package]]
+name = "unicode-normalization"
+version = "0.1.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c5713f0fc4b5db668a2ac63cdb7bb4469d8c9fed047b1d0292cc7b0ce2ba921"
+dependencies = [
+ "tinyvec",
+]
+
 [[package]]
 name = "universal-hash"
 version = "0.4.0"
@@ -2853,6 +2928,17 @@ version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a156c684c91ea7d62626509bce3cb4e1d9ed5c4d978f7b4352658f96a4c26b4a"
 
+[[package]]
+name = "url"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "143b538f18257fac9cad154828a57c6bf5157e1aa604d4816b5995bf6de87ae5"
+dependencies = [
+ "form_urlencoded",
+ "idna",
+ "percent-encoding",
+]
+
 [[package]]
 name = "version_check"
 version = "0.9.4"
@@ -3009,25 +3095,6 @@ dependencies = [
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "webpki"
-version = "0.22.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f095d78192e208183081cc07bc5515ef55216397af48b873e5edcd72637fa1bd"
-dependencies = [
- "ring",
- "untrusted",
-]
-
-[[package]]
-name = "webpki-roots"
-version = "0.22.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6c71e40d7d2c34a5106301fb632274ca37242cd0c9d3e64dbece371a40a2d87"
-dependencies = [
- "webpki",
-]
-
 [[package]]
 name = "winapi"
 version = "0.3.9"
diff --git a/metadata/src/lib.rs b/metadata/src/lib.rs
index 2ce1481e5e..b0186cab66 100644
--- a/metadata/src/lib.rs
+++ b/metadata/src/lib.rs
@@ -166,6 +166,45 @@ impl Metadata {
             &mut HashMap::new(),
         ))
     }
+
+    /// Ensure that every unique type we'll be generating or referring to also has a
+    /// unique path, so that types with matching paths don't end up overwriting each other
+    /// in the codegen. We ignore any types with generics; Subxt actually endeavours to
+    /// de-duplicate those into single types with a generic.
+    pub fn ensure_unique_type_paths(&mut self) {
+        let mut visited_path_counts = HashMap::<Vec<String>, usize>::new();
+        for ty in self.types.types.iter_mut() {
+            // Ignore types without a path (ie prelude types).
+            if ty.ty.path.namespace().is_empty() {
+                continue;
+            }
+
+            let has_valid_type_params = ty.ty.type_params.iter().any(|tp| tp.ty.is_some());
+
+            // Ignore types which have generic params that the type generation will use.
+            // Ordinarily we'd expect that any two types with identical paths must be parameterized
+            // in order to share the path. However scale-info doesn't understand all forms of generics
+            // properly I think (eg generics that have associated types that can differ), and so in
+            // those cases we need to fix the paths for Subxt to generate correct code.
+            if has_valid_type_params {
+                continue;
+            }
+
+            // Count how many times we've seen the same path already.
+            let visited_count = visited_path_counts
+                .entry(ty.ty.path.segments.clone())
+                .or_default();
+            *visited_count += 1;
+
+            // alter the type so that if it's been seen more than once, we append a number to
+            // its name to ensure that every unique type has a unique path, too.
+            if *visited_count > 1 {
+                if let Some(name) = ty.ty.path.segments.last_mut() {
+                    *name = format!("{name}{visited_count}");
+                }
+            }
+        }
+    }
 }
 
 /// Metadata for a specific pallet.
@@ -395,6 +434,23 @@ pub enum StorageEntryType {
     },
 }
 
+impl StorageEntryType {
+    /// The type of the value.
+    pub fn value_ty(&self) -> u32 {
+        match self {
+            StorageEntryType::Map { value_ty, .. } | StorageEntryType::Plain(value_ty) => *value_ty,
+        }
+    }
+
+    /// The type of the key, can be a tuple with elements for each of the hashers. None for a Plain storage entry.
+    pub fn key_ty(&self) -> Option<u32> {
+        match self {
+            StorageEntryType::Map { key_ty, .. } => Some(*key_ty),
+            StorageEntryType::Plain(_) => None,
+        }
+    }
+}
+
 /// Hasher used by storage maps.
 #[derive(Debug, Clone, Copy)]
 pub enum StorageHasher {