diff --git a/.github/workflows/ci-pr.yaml b/.github/workflows/ci-pr.yaml
index 812e36a..95e4cd6 100644
--- a/.github/workflows/ci-pr.yaml
+++ b/.github/workflows/ci-pr.yaml
@@ -29,6 +29,34 @@ jobs:
         with:
           command: check
 
+  external-types:
+    name: External Types (public API)
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Setup pinned nightly
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: nightly-2025-10-18
+
+      - name: Cache cargo
+        uses: Swatinem/rust-cache@v2
+
+      - name: Install just
+        uses: extractions/setup-just@v2
+
+      - name: Install cargo-binstall
+        uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-binstall
+
+      - name: Install cargo-check-external-types
+        run: cargo binstall cargo-check-external-types -y --force
+
+      - name: Run checks
+        run: just check-external-types
+
   reject-trailing-whitespace:
     uses: ./.github/workflows/trailing-whitespace.yaml
 
diff --git a/Cargo.lock b/Cargo.lock
index 1b8ff9b..c48b28b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4896,7 +4896,6 @@ version = "0.1.0"
 dependencies = [
  "getset",
  "hex",
- "http",
  "json",
  "portpicker",
  "serde_json",
diff --git a/Cargo.toml b/Cargo.toml
index 1e23705..e3f298d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,7 +13,6 @@ zebra-node-services = "3.0.0"
 zebra-rpc = "5.0.0"
 
 # other
-http = "1.1.0"
 getset = "0.1.3"
 hex = "0.4.3"
 json = "0.12.4"
diff --git a/justfile b/justfile
new file mode 100644
index 0000000..0b6cecc
--- /dev/null
+++ b/justfile
@@ -0,0 +1,12 @@
+# cargo-check-external-types requires this for now
+PINNED_NIGHTLY := "nightly-2025-10-18"
+
+check-external-types-zcash-local-net:
+    cargo +{{PINNED_NIGHTLY}} check-external-types --manifest-path zcash_local_net/Cargo.toml
+
+check-external-types-zingo-test-vectors:
+    cargo +{{PINNED_NIGHTLY}} check-external-types --manifest-path zingo_test_vectors/Cargo.toml
+
+check-external-types:
+    just check-external-types-zcash-local-net
+    just check-external-types-zingo-test-vectors
\ No newline at end of file
diff --git a/zcash_local_net/CHANGELOG.md b/zcash_local_net/CHANGELOG.md
index 04208fd..d8aae2d 100644
--- a/zcash_local_net/CHANGELOG.md
+++ b/zcash_local_net/CHANGELOG.md
@@ -10,25 +10,39 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Deprecated
 
 ### Added
-- support for Zebra 4.1.0
-- support for Zebra 4
+
+- Added `zcash_local_net::protocol` module to provide a stable, crate-owned path for protocol-related types exposed in the public API:
+  - Re-exported `PoolType`, `ActivationHeights`, `NetworkType`, and `RpcRequestClient`.
+- Added `zcash_local_net::external` module to provide a stable, crate-owned path for external helper types exposed in the public API:
+  - Re-exported `TempDir` via `zcash_local_net::external::TempDir` (and `zcash_local_net::TempDir`).
 
 ### Changed
+
+- Replaced `portpicker::Port` with `u16` across the public API for listen/port-related accessors and configuration setters, reducing external type leakage and simplifying callers:
+  - `indexer::empty::Empty::listen_port() -> u16`
+  - `indexer::lightwalletd::{Lightwalletd::port(), Lightwalletd::listen_port(), LightwalletdConfig::listen_port, LightwalletdConfig::set_listen_port(..)}`
+  - `indexer::zainod::{Zainod::port(), Zainod::listen_port(), ZainodConfig::{listen_port, validator_port}, ZainodConfig::set_listen_port(..)}`
+  - `network::pick_unused_port(fixed_port: Option<u16>) -> u16`
+  - `validator::zcashd::{Zcashd::port(), Zcashd::get_port(), ZcashdConfig::rpc_listen_port}`
+  - `validator::zebrad::{Zebrad::{indexer_listen_port(), network_listen_port(), rpc_listen_port(), get_port()}, ZebradConfig::{indexer_listen_port, network_listen_port, rpc_listen_port}}`
+  - `validator::Validator::get_port() -> u16`
+
 - `validator::Validator` trait:
   - `network`: now takes `ActivationHeights` instead of `ConfiguredActivationHeights`.
   - `load_chain`: now takes `NetworkType` instead of `NetworkKind`.
 - `validator::zcashd::ZcashdConfig`: changed `configured_activation_heights: ConfiguredActivationHeights` field to
-`activation_heights: ActivationHeights`. Removing the zebra-chain type from the public API and replacing with new
-zingo_common_components type.
+  `activation_heights: ActivationHeights`. Removing the zebra-chain type from the public API and replacing with new
+  zingo_common_components type.
 - `validator::zebrad::ZebradConfig`:
   - changed `network: NetworkKind` to `network_type: NetworkType`. Removing the
-zebra-chain type from the public API and replacing with new zingo_common_components type.
+    zebra-chain type from the public API and replacing with new zingo_common_components type.
   - `with_regtest_enabled` method: now takes `ActivationHeights` instead of `ConfiguredActivationHeights`.
   - `set_test_parameters` method: now takes `ActivationHeights` instead of `ConfiguredActivationHeights`.
 
 ### Removed
+
+- Removed `network::localhost_uri(port: portpicker::Port) -> http::Uri` from the public API. (Callers should construct URIs using their own `u16` port value, or via a replacement helper if provided elsewhere.)
 - `validator::zebrad::ZebradConfig`: removed `configured_activation_heights: ConfiguredActivationHeights` field removing the
-zebra-chain type from the public API. Replaced by new `network_type` field which includes activation heights.
+  zebra-chain type from the public API. Replaced by new `network_type` field which includes activation heights.
 
 ## [0.1.0]
-
diff --git a/zcash_local_net/Cargo.toml b/zcash_local_net/Cargo.toml
index 1dbae03..338072d 100644
--- a/zcash_local_net/Cargo.toml
+++ b/zcash_local_net/Cargo.toml
@@ -24,7 +24,6 @@ zebra-chain = { workspace = true }
 # Community
 tempfile = { workspace = true }
 portpicker = { workspace = true }
-http = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 getset = { workspace = true }
@@ -39,3 +38,12 @@ tracing-subscriber = { workspace = true }
 [build-dependencies]
 hex = { workspace = true }
 tokio = { workspace = true, features = ["macros", "fs", "rt-multi-thread"] }
+
+[package.metadata.cargo_check_external_types]
+allowed_external_types = [
+    "tempfile::dir::TempDir",
+    "zcash_protocol::PoolType",
+    "zingo_common_components::protocol::ActivationHeights",
+    "zingo_common_components::protocol::NetworkType",
+    "zebra_node_services::rpc_client::RpcRequestClient",
+]
diff --git a/zcash_local_net/src/config.rs b/zcash_local_net/src/config.rs
index b57e1fb..da4fef1 100644
--- a/zcash_local_net/src/config.rs
+++ b/zcash_local_net/src/config.rs
@@ -4,8 +4,6 @@ use std::fs::File;
 use std::io::{BufWriter, Write};
 use std::path::{Path, PathBuf};
 
-use portpicker::Port;
-
 use zingo_common_components::protocol::{ActivationHeights, NetworkType};
 
 /// Convert `NetworkKind` to its config string representation
@@ -27,7 +25,7 @@ pub(crate) const LIGHTWALLETD_FILENAME: &str = "lightwalletd.yml";
 /// Returns the path to the config file.
 pub(crate) fn write_zcashd_config(
     config_dir: &Path,
-    rpc_port: Port,
+    rpc_port: u16,
     activation_heights: ActivationHeights,
     miner_address: Option<&str>,
 ) -> std::io::Result<PathBuf> {
@@ -120,9 +118,9 @@ minetolocalwallet=0 # This is set to false so that we can mine to a wallet, othe
 pub(crate) fn write_zebrad_config(
     output_config_dir: PathBuf,
     cache_dir: PathBuf,
-    network_listen_port: Port,
-    rpc_listen_port: Port,
-    indexer_listen_port: Port,
+    network_listen_port: u16,
+    rpc_listen_port: u16,
+    indexer_listen_port: u16,
     miner_address: &str,
     network: NetworkType,
 ) -> std::io::Result<PathBuf> {
@@ -234,8 +232,8 @@ NU6 = {nu6_activation_height}
 pub(crate) fn write_zainod_config(
     config_dir: &Path,
     validator_cache_dir: PathBuf,
-    listen_port: Port,
-    validator_port: Port,
+    listen_port: u16,
+    validator_port: u16,
     network: NetworkType,
 ) -> std::io::Result<PathBuf> {
     let config_file_path = config_dir.join(ZAINOD_FILENAME);
@@ -274,7 +272,7 @@ database.path = \"{chain_cache}\""
 #[allow(dead_code)]
 pub(crate) fn write_lightwalletd_config(
     config_dir: &Path,
-    grpc_bind_addr_port: Port,
+    grpc_bind_addr_port: u16,
     log_file: PathBuf,
     zcashd_conf: PathBuf,
 ) -> std::io::Result<PathBuf> {
diff --git a/zcash_local_net/src/indexer.rs b/zcash_local_net/src/indexer.rs
index 25b7f1f..0716e54 100644
--- a/zcash_local_net/src/indexer.rs
+++ b/zcash_local_net/src/indexer.rs
@@ -3,14 +3,12 @@
 //! Processes which are not strictly indexers but have a similar role in serving light-clients/light-wallets
 //! (i.e. Lightwalletd) are also included in this category and are referred to as "light-nodes".
 
-use portpicker::Port;
-
 use crate::{process::Process, validator::Validator};
 
 /// Can offer specific functionality shared across configuration for all indexers.
 pub trait IndexerConfig: Default + std::fmt::Debug {
     /// To receive a port to instruct an indexer to listen at.
-    fn set_listen_port(&mut self, indexer_listen_port: Option<Port>);
+    fn set_listen_port(&mut self, indexer_listen_port: Option<u16>);
     /// To receive a port to instruct an indexer to listen at.
     fn setup_validator_connection<V: Validator>(&mut self, validator: &V);
 }
@@ -18,7 +16,7 @@ pub trait IndexerConfig: Default + std::fmt::Debug {
 /// Functionality for indexer/light-node processes.
 pub trait Indexer: Process<Config: IndexerConfig> + std::fmt::Debug {
     /// Indexer listen port
-    fn listen_port(&self) -> Port;
+    fn listen_port(&self) -> u16;
 }
 
 /// The Zainod executable support struct.
diff --git a/zcash_local_net/src/indexer/empty.rs b/zcash_local_net/src/indexer/empty.rs
index 069a183..660e42b 100644
--- a/zcash_local_net/src/indexer/empty.rs
+++ b/zcash_local_net/src/indexer/empty.rs
@@ -1,5 +1,4 @@
 use getset::{CopyGetters, Getters};
-use portpicker::Port;
 use tempfile::TempDir;
 
 use crate::{
@@ -21,7 +20,7 @@ impl IndexerConfig for EmptyConfig {
         tracing::info!("Empty Validator cannot accept a port!");
     }
 
-    fn set_listen_port(&mut self, indexer_listen_port: Option<Port>) {
+    fn set_listen_port(&mut self, indexer_listen_port: Option<u16>) {
         panic!("Empty validator cannot listen on port! {indexer_listen_port:?}");
     }
 }
@@ -78,7 +77,7 @@ impl Drop for Empty {
 }
 
 impl Indexer for Empty {
-    fn listen_port(&self) -> Port {
+    fn listen_port(&self) -> u16 {
         0
     }
 }
diff --git a/zcash_local_net/src/indexer/lightwalletd.rs b/zcash_local_net/src/indexer/lightwalletd.rs
index 0f0dde4..db2869b 100644
--- a/zcash_local_net/src/indexer/lightwalletd.rs
+++ b/zcash_local_net/src/indexer/lightwalletd.rs
@@ -1,7 +1,6 @@
 use std::{fs::File, path::PathBuf, process::Child};
 
 use getset::{CopyGetters, Getters};
-use portpicker::Port;
 use tempfile::TempDir;
 
 use crate::{
@@ -26,7 +25,7 @@ use crate::{
 #[derive(Debug)]
 pub struct LightwalletdConfig {
     /// Listen RPC port
-    pub listen_port: Option<Port>,
+    pub listen_port: Option<u16>,
     /// Zcashd configuration file location. Required even when running non-Zcashd validators.
     pub zcashd_conf: PathBuf,
     /// Enables darkside
@@ -48,7 +47,7 @@ impl IndexerConfig for LightwalletdConfig {
         self.zcashd_conf = validator.get_zcashd_conf_path();
     }
 
-    fn set_listen_port(&mut self, indexer_listen_port: Option<Port>) {
+    fn set_listen_port(&mut self, indexer_listen_port: Option<u16>) {
         self.listen_port = indexer_listen_port;
     }
 }
@@ -61,7 +60,7 @@ pub struct Lightwalletd {
     /// RPC Port
     #[getset(skip)]
     #[getset(get_copy = "pub")]
-    port: Port,
+    port: u16,
     /// Data directory
     _data_dir: TempDir,
     /// Logs directory
@@ -163,7 +162,7 @@ impl Process for Lightwalletd {
 }
 
 impl Indexer for Lightwalletd {
-    fn listen_port(&self) -> Port {
+    fn listen_port(&self) -> u16 {
         self.port
     }
 }
diff --git a/zcash_local_net/src/indexer/zainod.rs b/zcash_local_net/src/indexer/zainod.rs
index 7d42f0a..012eca2 100644
--- a/zcash_local_net/src/indexer/zainod.rs
+++ b/zcash_local_net/src/indexer/zainod.rs
@@ -3,7 +3,6 @@
 use std::{path::PathBuf, process::Child};
 
 use getset::{CopyGetters, Getters};
-use portpicker::Port;
 use tempfile::TempDir;
 
 use zingo_common_components::protocol::{ActivationHeights, NetworkType};
@@ -33,9 +32,9 @@ use crate::{
 #[derive(Debug)]
 pub struct ZainodConfig {
     /// Listen RPC port
-    pub listen_port: Option<Port>,
+    pub listen_port: Option<u16>,
     /// Validator RPC port
-    pub validator_port: Port,
+    pub validator_port: u16,
     /// Chain cache path
     pub chain_cache: Option<PathBuf>,
     /// Network type.
@@ -58,7 +57,7 @@ impl IndexerConfig for ZainodConfig {
         self.validator_port = validator.get_port();
     }
 
-    fn set_listen_port(&mut self, indexer_listen_port: Option<Port>) {
+    fn set_listen_port(&mut self, indexer_listen_port: Option<u16>) {
         self.listen_port = indexer_listen_port;
     }
 }
@@ -72,7 +71,7 @@ pub struct Zainod {
     /// RPC port
     #[getset(skip)]
     #[getset(get_copy = "pub")]
-    port: Port,
+    port: u16,
     /// Logs directory
     logs_dir: TempDir,
     /// Config directory
@@ -154,7 +153,7 @@ impl Process for Zainod {
 }
 
 impl Indexer for Zainod {
-    fn listen_port(&self) -> Port {
+    fn listen_port(&self) -> u16 {
         self.port
     }
 }
diff --git a/zcash_local_net/src/lib.rs b/zcash_local_net/src/lib.rs
index 471e292..e29c3e7 100644
--- a/zcash_local_net/src/lib.rs
+++ b/zcash_local_net/src/lib.rs
@@ -49,6 +49,18 @@ use crate::{
 
 pub use zcash_protocol::PoolType;
 
+/// External re-exported zcash types.
+pub mod protocol {
+    pub use zcash_protocol::PoolType;
+    pub use zebra_node_services::rpc_client::RpcRequestClient;
+    pub use zingo_common_components::protocol::{ActivationHeights, NetworkType};
+}
+
+/// External re-exported types.
+pub mod external {
+    pub use tempfile::TempDir;
+}
+
 /// All processes currently supported
 #[derive(Clone, Copy)]
 #[allow(missing_docs)]
diff --git a/zcash_local_net/src/network.rs b/zcash_local_net/src/network.rs
index 5ebead8..49de104 100644
--- a/zcash_local_net/src/network.rs
+++ b/zcash_local_net/src/network.rs
@@ -1,13 +1,9 @@
 //! Structs and utility functions associated with local network configuration
 
-use portpicker::Port;
-
-pub(crate) const LOCALHOST_IPV4: &str = "http://127.0.0.1";
-
 /// Checks `fixed_port` is not in use.
 /// If `fixed_port` is `None`, returns a random free port between `15_000` and `25_000`.
 #[must_use]
-pub fn pick_unused_port(fixed_port: Option<Port>) -> Port {
+pub fn pick_unused_port(fixed_port: Option<u16>) -> u16 {
     if let Some(port) = fixed_port {
         assert!(portpicker::is_free(port), "Fixed port is not free!");
         port
@@ -15,9 +11,3 @@ pub fn pick_unused_port(fixed_port: Option<Port>) -> Port {
         portpicker::pick_unused_port().expect("No ports free!")
     }
 }
-
-/// Constructs a URI with the localhost IPv4 address and the specified port.
-#[must_use]
-pub fn localhost_uri(port: Port) -> http::Uri {
-    format!("{LOCALHOST_IPV4}:{port}").try_into().unwrap()
-}
diff --git a/zcash_local_net/src/utils.rs b/zcash_local_net/src/utils.rs
index d95680d..5e08a20 100644
--- a/zcash_local_net/src/utils.rs
+++ b/zcash_local_net/src/utils.rs
@@ -16,22 +16,3 @@ pub(crate) fn cargo_manifest_dir() -> PathBuf {
 pub fn chain_cache_dir() -> PathBuf {
     cargo_manifest_dir().join("chain_cache")
 }
-
-// // NOTE: this should be migrated to zingolib when LocalNet replaces regtest manager in zingoilb::testutils
-// /// Builds faucet (miner) and recipient lightclients for local network integration testing
-// pub fn build_lightclients(
-//     lightclient_dir: PathBuf,
-//     indexer_port: Port,
-// ) -> (LightClient, LightClient) {
-//     let mut client_builder =
-//         ClientBuilder::new(network::localhost_uri(indexer_port), lightclient_dir);
-//     let faucet = client_builder.build_faucet(true, RegtestNetwork::all_upgrades_active());
-//     let recipient = client_builder.build_client(
-//         seeds::HOSPITAL_MUSEUM_SEED.to_string(),
-//         1,
-//         true,
-//         RegtestNetwork::all_upgrades_active(),
-//     );
-
-//     (faucet, recipient)
-// }
diff --git a/zcash_local_net/src/validator.rs b/zcash_local_net/src/validator.rs
index d866312..88ef7ff 100644
--- a/zcash_local_net/src/validator.rs
+++ b/zcash_local_net/src/validator.rs
@@ -1,7 +1,6 @@
 //! Module for the structs that represent and manage the validator/full-node processes i.e. Zebrad.
 use std::path::PathBuf;
 
-use portpicker::Port;
 use tempfile::TempDir;
 use zcash_protocol::PoolType;
 use zingo_common_components::protocol::{ActivationHeights, NetworkType};
@@ -121,5 +120,5 @@ pub trait Validator: Process<Config: ValidatorConfig> + std::fmt::Debug {
     ) -> PathBuf;
 
     /// To reveal a port.
-    fn get_port(&self) -> Port;
+    fn get_port(&self) -> u16;
 }
diff --git a/zcash_local_net/src/validator/zcashd.rs b/zcash_local_net/src/validator/zcashd.rs
index 90ded54..19a7be6 100644
--- a/zcash_local_net/src/validator/zcashd.rs
+++ b/zcash_local_net/src/validator/zcashd.rs
@@ -3,7 +3,6 @@
 use std::{path::PathBuf, process::Child};
 
 use getset::{CopyGetters, Getters};
-use portpicker::Port;
 use tempfile::TempDir;
 
 use zcash_protocol::PoolType;
@@ -43,7 +42,7 @@ use crate::{
 #[derive(Debug)]
 pub struct ZcashdConfig {
     /// Zcashd RPC listen port
-    pub rpc_listen_port: Option<Port>,
+    pub rpc_listen_port: Option<u16>,
     /// Local network upgrade activation heights
     pub activation_heights: ActivationHeights,
     /// Miner address
@@ -89,7 +88,7 @@ pub struct Zcashd {
     /// RPC port
     #[getset(skip)]
     #[getset(get_copy = "pub")]
-    port: Port,
+    port: u16,
     /// Config directory
     config_dir: TempDir,
     /// Logs directory
@@ -311,7 +310,7 @@ impl Validator for Zcashd {
         chain_cache
     }
 
-    fn get_port(&self) -> Port {
+    fn get_port(&self) -> u16 {
         self.port()
     }
 }
diff --git a/zcash_local_net/src/validator/zebrad.rs b/zcash_local_net/src/validator/zebrad.rs
index 7028809..fc339d3 100644
--- a/zcash_local_net/src/validator/zebrad.rs
+++ b/zcash_local_net/src/validator/zebrad.rs
@@ -25,7 +25,6 @@ use std::{
 };
 
 use getset::{CopyGetters, Getters};
-use portpicker::Port;
 use tempfile::TempDir;
 use zebra_chain::serialization::ZcashSerialize as _;
 use zebra_node_services::rpc_client::RpcRequestClient;
@@ -52,11 +51,11 @@ use zebra_rpc::{
 #[derive(Clone, Debug)]
 pub struct ZebradConfig {
     /// Zebrad network listen port
-    pub network_listen_port: Option<Port>,
+    pub network_listen_port: Option<u16>,
     /// Zebrad JSON-RPC listen port
-    pub rpc_listen_port: Option<Port>,
+    pub rpc_listen_port: Option<u16>,
     /// Zebrad gRPC listen port
-    pub indexer_listen_port: Option<Port>,
+    pub indexer_listen_port: Option<u16>,
     /// Miner address
     pub miner_address: String,
     /// Chain cache path
@@ -114,15 +113,15 @@ pub struct Zebrad {
     /// network listen port
     #[getset(skip)]
     #[getset(get_copy = "pub")]
-    network_listen_port: Port,
+    network_listen_port: u16,
     /// json RPC listen port
     #[getset(skip)]
     #[getset(get_copy = "pub")]
-    rpc_listen_port: Port,
+    rpc_listen_port: u16,
     /// gRPC listen port
     #[getset(skip)]
     #[getset(get_copy = "pub")]
-    indexer_listen_port: Port,
+    indexer_listen_port: u16,
     /// Config directory
     config_dir: TempDir,
     /// Logs directory
@@ -390,7 +389,7 @@ impl Validator for Zebrad {
         }
     }
 
-    fn get_port(&self) -> Port {
+    fn get_port(&self) -> u16 {
         self.rpc_listen_port()
     }
 }