diff --git a/Cargo.lock b/Cargo.lock
index 21d8ae9a98..55aedbcad2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -8174,10 +8174,11 @@ name = "spin-app"
 version = "3.4.0-pre0"
 dependencies = [
  "anyhow",
+ "itertools 0.14.0",
  "serde",
  "serde_json",
- "spin-factors-test",
- "spin-locked-app",
+ "spin-serde",
+ "thiserror 2.0.12",
  "tokio",
  "toml",
 ]
@@ -8243,7 +8244,6 @@ dependencies = [
  "spin-factor-outbound-networking",
  "spin-http",
  "spin-loader",
- "spin-locked-app",
  "spin-manifest",
  "spin-oci",
  "spin-plugins",
@@ -8332,11 +8332,11 @@ dependencies = [
  "anyhow",
  "async-trait",
  "serde_json",
+ "spin-app",
  "spin-componentize",
  "spin-factor-wasi",
  "spin-factors",
  "spin-factors-test",
- "spin-locked-app",
  "tokio",
  "tracing",
  "wasmtime",
@@ -8371,7 +8371,7 @@ dependencies = [
  "anyhow",
  "async-trait",
  "futures",
- "spin-locked-app",
+ "spin-app",
  "thiserror 2.0.12",
  "tokio",
  "toml",
@@ -8383,12 +8383,12 @@ version = "3.4.0-pre0"
 dependencies = [
  "anyhow",
  "serde",
+ "spin-app",
  "spin-core",
  "spin-factors",
  "spin-factors-test",
  "spin-key-value-redis",
  "spin-key-value-spin",
- "spin-locked-app",
  "spin-resource-table",
  "spin-telemetry",
  "spin-world",
@@ -8406,11 +8406,11 @@ dependencies = [
  "anyhow",
  "async-trait",
  "serde",
+ "spin-app",
  "spin-factors",
  "spin-factors-test",
  "spin-llm-local",
  "spin-llm-remote-http",
- "spin-locked-app",
  "spin-telemetry",
  "spin-world",
  "tokio",
@@ -8493,11 +8493,11 @@ dependencies = [
  "rustls 0.23.18",
  "rustls-pki-types",
  "serde",
+ "spin-app",
  "spin-factor-variables",
  "spin-factor-wasi",
  "spin-factors",
  "spin-factors-test",
- "spin-locked-app",
  "spin-manifest",
  "spin-outbound-networking-config",
  "spin-serde",
@@ -8559,9 +8559,9 @@ name = "spin-factor-sqlite"
 version = "3.4.0-pre0"
 dependencies = [
  "async-trait",
+ "spin-app",
  "spin-factors",
  "spin-factors-test",
- "spin-locked-app",
  "spin-resource-table",
  "spin-world",
  "tokio",
@@ -8640,6 +8640,7 @@ dependencies = [
  "spin-loader",
  "spin-telemetry",
  "tempfile",
+ "tokio",
  "toml",
 ]
 
@@ -8779,9 +8780,9 @@ dependencies = [
  "serde",
  "serde_json",
  "sha2",
+ "spin-app",
  "spin-common",
  "spin-expressions",
- "spin-locked-app",
  "spin-manifest",
  "spin-outbound-networking-config",
  "spin-serde",
@@ -8794,19 +8795,6 @@ dependencies = [
  "wasm-pkg-client",
 ]
 
-[[package]]
-name = "spin-locked-app"
-version = "3.4.0-pre0"
-dependencies = [
- "anyhow",
- "async-trait",
- "itertools 0.14.0",
- "serde",
- "serde_json",
- "spin-serde",
- "thiserror 2.0.12",
-]
-
 [[package]]
 name = "spin-manifest"
 version = "3.4.0-pre0"
@@ -8845,10 +8833,10 @@ dependencies = [
  "reqwest 0.12.9",
  "serde",
  "serde_json",
+ "spin-app",
  "spin-common",
  "spin-compose",
  "spin-loader",
- "spin-locked-app",
  "tempfile",
  "tokio",
  "tokio-util",
diff --git a/Cargo.toml b/Cargo.toml
index 51065b44ee..723f4ba291 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -58,7 +58,6 @@ spin-doctor = { path = "crates/doctor" }
 spin-factor-outbound-networking = { path = "crates/factor-outbound-networking" }
 spin-http = { path = "crates/http" }
 spin-loader = { path = "crates/loader" }
-spin-locked-app = { path = "crates/locked-app" }
 spin-manifest = { path = "crates/manifest" }
 spin-oci = { path = "crates/oci" }
 spin-plugins = { path = "crates/plugins" }
diff --git a/crates/app/Cargo.toml b/crates/app/Cargo.toml
index 94bbfa7c27..29adbb755d 100644
--- a/crates/app/Cargo.toml
+++ b/crates/app/Cargo.toml
@@ -6,11 +6,12 @@ edition = { workspace = true }
 
 [dependencies]
 anyhow = { workspace = true }
+itertools = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
-spin-locked-app = { path = "../locked-app" }
+spin-serde = { path = "../serde" }
+thiserror = { workspace = true }
 
 [dev-dependencies]
 toml = { workspace = true }
-spin-factors-test = { path = "../factors-test" }
 tokio = { workspace = true }
\ No newline at end of file
diff --git a/crates/app/src/error.rs b/crates/app/src/error.rs
new file mode 100644
index 0000000000..16fcf253ff
--- /dev/null
+++ b/crates/app/src/error.rs
@@ -0,0 +1,25 @@
+/// Type alias for a [`Result`]s with [`Error`].
+pub type Result<T> = std::result::Result<T, Error>;
+
+/// Errors returned by methods in this crate.
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    /// An error propagated from the `spin_core` crate.
+    #[error(transparent)]
+    Core(anyhow::Error),
+    /// An error from a `DynamicHostComponent`.
+    #[error("host component error: {0:#}")]
+    HostComponent(#[source] anyhow::Error),
+    /// An error from a `Loader` implementation.
+    #[error(transparent)]
+    Loader(anyhow::Error),
+    /// An error indicating missing or unexpected metadata.
+    #[error("metadata error: {0}")]
+    Metadata(String),
+    /// An error indicating failed JSON (de)serialization.
+    #[error("json error: {0}")]
+    Json(#[from] serde_json::Error),
+    /// A validation error that can be presented directly to the user.
+    #[error(transparent)]
+    Validation(anyhow::Error),
+}
diff --git a/crates/app/src/lib.rs b/crates/app/src/lib.rs
index 3f2a0098cc..8830ebb729 100644
--- a/crates/app/src/lib.rs
+++ b/crates/app/src/lib.rs
@@ -11,15 +11,22 @@ use std::sync::Arc;
 
 use serde::Deserialize;
 use serde_json::Value;
-use spin_locked_app::MetadataExt;
 
-use locked::{ContentPath, LockedApp, LockedComponent, LockedComponentSource, LockedTrigger};
+use crate::locked::{
+    ContentPath, LockedApp, LockedComponent, LockedComponentSource, LockedTrigger,
+};
 
-pub use spin_locked_app::locked;
-pub use spin_locked_app::values;
-pub use spin_locked_app::{Error, MetadataKey, Result};
+pub use crate::locked::Variable;
 
-pub use locked::Variable;
+use crate::error::{Error, Result};
+use crate::metadata::MetadataExt as _;
+
+mod error;
+pub mod locked;
+mod metadata;
+pub mod values;
+
+pub use metadata::MetadataKey;
 
 /// MetadataKey for extracting the application name.
 pub const APP_NAME_KEY: MetadataKey = MetadataKey::new("name");
@@ -121,7 +128,7 @@ impl App {
             return Ok(None);
         };
         let metadata = T::deserialize(value).map_err(|err| {
-            Error::MetadataError(format!(
+            Error::Metadata(format!(
                 "invalid metadata value for {trigger_type:?}: {err:?}"
             ))
         })?;
@@ -186,7 +193,7 @@ impl App {
     ) -> Result<LockedApp> {
         self.validate_retained_components_exist(retained_components)?;
         for validator in validators {
-            validator(&self, retained_components).map_err(Error::ValidationError)?;
+            validator(&self, retained_components).map_err(Error::Validation)?;
         }
         let (component_ids, trigger_ids): (HashSet<String>, HashSet<String>) = self
             .triggers()
@@ -211,7 +218,7 @@ impl App {
             .collect::<HashSet<_>>();
         for c in retained_components {
             if !app_components.contains(*c) {
-                return Err(Error::ValidationError(anyhow::anyhow!(
+                return Err(Error::Validation(anyhow::anyhow!(
                     "Specified component \"{c}\" not found in application"
                 )));
             }
@@ -310,10 +317,10 @@ impl<'a> AppTrigger<'a> {
         let id = &self.locked.id;
         let common_config: CommonTriggerConfig = self.typed_config()?;
         let component_id = common_config.component.ok_or_else(|| {
-            Error::MetadataError(format!("trigger {id:?} missing 'component' config field"))
+            Error::Metadata(format!("trigger {id:?} missing 'component' config field"))
         })?;
         self.app.get_component(&component_id).ok_or_else(|| {
-            Error::MetadataError(format!(
+            Error::Metadata(format!(
                 "missing component {component_id:?} configured for trigger {id:?}"
             ))
         })
@@ -337,29 +344,45 @@ pub fn retain_components(
 
 #[cfg(test)]
 mod test {
-    use spin_factors_test::build_locked_app;
+    use std::collections::HashSet;
 
     use super::*;
 
+    pub fn locked_app() -> LockedApp {
+        LockedApp {
+            spin_lock_version: Default::default(),
+            must_understand: Default::default(),
+            metadata: Default::default(),
+            host_requirements: Default::default(),
+            variables: Default::default(),
+            triggers: vec![LockedTrigger {
+                id: "trigger".into(),
+                trigger_type: "dummy".into(),
+                trigger_config: toml::from_str(r#"component = "empty""#).unwrap(),
+            }],
+            components: vec![LockedComponent {
+                id: "empty".to_owned(),
+                metadata: Default::default(),
+                source: LockedComponentSource {
+                    content_type: "application/wasm".to_owned(),
+                    content: Default::default(),
+                },
+                env: Default::default(),
+                files: Default::default(),
+                config: Default::default(),
+                dependencies: Default::default(),
+                host_requirements: Default::default(),
+            }],
+        }
+    }
+
     fn does_nothing_validator(_: &App, _: &[&str]) -> anyhow::Result<()> {
         Ok(())
     }
 
     #[tokio::test]
     async fn test_retain_components_filtering_for_only_component_works() {
-        let manifest = toml::toml! {
-            spin_manifest_version = 2
-
-            [application]
-            name = "test-app"
-
-            [[trigger.test-trigger]]
-            component = "empty"
-
-            [component.empty]
-            source = "does-not-exist.wasm"
-        };
-        let mut locked_app = build_locked_app(&manifest).await.unwrap();
+        let mut locked_app = locked_app();
         locked_app = retain_components(locked_app, &["empty"], &[&does_nothing_validator]).unwrap();
         let components = locked_app
             .components
diff --git a/crates/locked-app/src/locked.rs b/crates/app/src/locked.rs
similarity index 100%
rename from crates/locked-app/src/locked.rs
rename to crates/app/src/locked.rs
diff --git a/crates/locked-app/src/metadata.rs b/crates/app/src/metadata.rs
similarity index 88%
rename from crates/locked-app/src/metadata.rs
rename to crates/app/src/metadata.rs
index cfb487ce4d..5e50ad7e03 100644
--- a/crates/locked-app/src/metadata.rs
+++ b/crates/app/src/metadata.rs
@@ -57,16 +57,14 @@ pub trait MetadataExt {
         self.get_value(key.as_ref())
             .map(T::deserialize)
             .transpose()
-            .map_err(|err| {
-                Error::MetadataError(format!("invalid metadata value for {key:?}: {err:?}"))
-            })
+            .map_err(|err| Error::Metadata(format!("invalid metadata value for {key:?}: {err:?}")))
     }
 
     /// Get a required value from a metadata map, returning an error
     /// if it is not present
     fn require_typed<'a, T: Deserialize<'a>>(&'a self, key: MetadataKey<T>) -> Result<T> {
         self.get_typed(key)?
-            .ok_or_else(|| Error::MetadataError(format!("missing required metadata {key:?}")))
+            .ok_or_else(|| Error::Metadata(format!("missing required metadata {key:?}")))
     }
 }
 
diff --git a/crates/locked-app/src/values.rs b/crates/app/src/values.rs
similarity index 100%
rename from crates/locked-app/src/values.rs
rename to crates/app/src/values.rs
diff --git a/crates/core/Cargo.toml b/crates/core/Cargo.toml
index c6d324991e..e0bed88c7b 100644
--- a/crates/core/Cargo.toml
+++ b/crates/core/Cargo.toml
@@ -16,7 +16,7 @@ spin-componentize = { workspace = true }
 spin-factor-wasi = { path = "../factor-wasi" }
 spin-factors = { path = "../factors" }
 spin-factors-test = { path = "../factors-test" }
-spin-locked-app = { path = "../locked-app" }
+spin-app = { path = "../app" }
 tokio = { workspace = true, features = ["macros", "rt", "rt-multi-thread"] }
 wasmtime-wasi = { workspace = true }
 
diff --git a/crates/core/tests/integration_test.rs b/crates/core/tests/integration_test.rs
index 7d2c1aca3d..09d5976279 100644
--- a/crates/core/tests/integration_test.rs
+++ b/crates/core/tests/integration_test.rs
@@ -5,10 +5,10 @@ use std::{
 
 use anyhow::Context;
 use serde_json::json;
+use spin_app::locked::LockedApp;
 use spin_core::{AsState, Component, Config, Engine, State, Store, StoreBuilder, Trap};
 use spin_factor_wasi::{DummyFilesMounter, WasiFactor};
 use spin_factors::{App, AsInstanceState, RuntimeFactors};
-use spin_locked_app::locked::LockedApp;
 use tokio::{fs, io::AsyncWrite};
 use wasmtime_wasi::I32Exit;
 
diff --git a/crates/expressions/Cargo.toml b/crates/expressions/Cargo.toml
index 6c9749fb4d..50ee221b5d 100644
--- a/crates/expressions/Cargo.toml
+++ b/crates/expressions/Cargo.toml
@@ -8,7 +8,7 @@ edition = { workspace = true }
 anyhow = { workspace = true }
 async-trait = { workspace = true }
 futures = { workspace = true }
-spin-locked-app = { path = "../locked-app" }
+spin-app = { path = "../app" }
 thiserror = { workspace = true }
 
 [dev-dependencies]
diff --git a/crates/expressions/src/lib.rs b/crates/expressions/src/lib.rs
index 2219044372..eaae990522 100644
--- a/crates/expressions/src/lib.rs
+++ b/crates/expressions/src/lib.rs
@@ -3,7 +3,7 @@ mod template;
 
 use std::{borrow::Cow, collections::HashMap, fmt::Debug};
 
-use spin_locked_app::Variable;
+use spin_app::Variable;
 
 pub use async_trait;
 
diff --git a/crates/factor-key-value/Cargo.toml b/crates/factor-key-value/Cargo.toml
index 8327737bd1..6273b11863 100644
--- a/crates/factor-key-value/Cargo.toml
+++ b/crates/factor-key-value/Cargo.toml
@@ -9,7 +9,7 @@ anyhow = { workspace = true }
 serde = { workspace = true }
 spin-core = { path = "../core" }
 spin-factors = { path = "../factors" }
-spin-locked-app = { path = "../locked-app" }
+spin-app = { path = "../app" }
 spin-resource-table = { path = "../table" }
 spin-telemetry = { path = "../telemetry" }
 spin-world = { path = "../world" }
diff --git a/crates/factor-key-value/src/lib.rs b/crates/factor-key-value/src/lib.rs
index 792ea18b92..2567c1c2e2 100644
--- a/crates/factor-key-value/src/lib.rs
+++ b/crates/factor-key-value/src/lib.rs
@@ -8,11 +8,11 @@ use std::{
 };
 
 use anyhow::ensure;
+use spin_app::MetadataKey;
 use spin_factors::{
     ConfigureAppContext, Factor, FactorData, FactorInstanceBuilder, InitContext, PrepareContext,
     RuntimeFactors,
 };
-use spin_locked_app::MetadataKey;
 
 /// Metadata key for key-value stores.
 pub const KEY_VALUE_STORES_KEY: MetadataKey<Vec<String>> = MetadataKey::new("key_value_stores");
diff --git a/crates/factor-llm/Cargo.toml b/crates/factor-llm/Cargo.toml
index c43a7bbd6c..51d3a9d5b1 100644
--- a/crates/factor-llm/Cargo.toml
+++ b/crates/factor-llm/Cargo.toml
@@ -20,7 +20,7 @@ serde = { workspace = true }
 spin-factors = { path = "../factors" }
 spin-llm-local = { path = "../llm-local", optional = true }
 spin-llm-remote-http = { path = "../llm-remote-http" }
-spin-locked-app = { path = "../locked-app" }
+spin-app = { path = "../app" }
 spin-telemetry = { path = "../telemetry" }
 spin-world = { path = "../world" }
 tokio = { workspace = true, features = ["sync"] }
diff --git a/crates/factor-llm/src/lib.rs b/crates/factor-llm/src/lib.rs
index 4f43feac68..d1b386db30 100644
--- a/crates/factor-llm/src/lib.rs
+++ b/crates/factor-llm/src/lib.rs
@@ -5,10 +5,10 @@ use std::collections::{HashMap, HashSet};
 use std::sync::Arc;
 
 use async_trait::async_trait;
+use spin_app::MetadataKey;
 use spin_factors::{
     ConfigureAppContext, Factor, FactorData, PrepareContext, RuntimeFactors, SelfInstanceBuilder,
 };
-use spin_locked_app::MetadataKey;
 use spin_world::v1::llm::{self as v1};
 use spin_world::v2::llm::{self as v2};
 use tokio::sync::Mutex;
diff --git a/crates/factor-outbound-networking/Cargo.toml b/crates/factor-outbound-networking/Cargo.toml
index b94a75fa2c..15143ac171 100644
--- a/crates/factor-outbound-networking/Cargo.toml
+++ b/crates/factor-outbound-networking/Cargo.toml
@@ -15,7 +15,7 @@ serde = { workspace = true }
 spin-factor-variables = { path = "../factor-variables" }
 spin-factor-wasi = { path = "../factor-wasi" }
 spin-factors = { path = "../factors" }
-spin-locked-app = { path = "../locked-app" }
+spin-app = { path = "../app" }
 spin-manifest = { path = "../manifest" }
 spin-outbound-networking-config = { path = "../outbound-networking-config" }
 spin-serde = { path = "../serde" }
diff --git a/crates/factor-outbound-networking/src/allowed_hosts.rs b/crates/factor-outbound-networking/src/allowed_hosts.rs
index 0a736eb6bf..43e146aa75 100644
--- a/crates/factor-outbound-networking/src/allowed_hosts.rs
+++ b/crates/factor-outbound-networking/src/allowed_hosts.rs
@@ -1,6 +1,6 @@
 use anyhow::Context as _;
+use spin_app::MetadataKey;
 use spin_factors::{App, AppComponent};
-use spin_locked_app::MetadataKey;
 use spin_outbound_networking_config::allowed_hosts::parse_service_chaining_target;
 
 const ALLOWED_HOSTS_KEY: MetadataKey<Vec<String>> = MetadataKey::new("allowed_outbound_hosts");
diff --git a/crates/factor-sqlite/Cargo.toml b/crates/factor-sqlite/Cargo.toml
index ee945ed4fa..956a6f5b75 100644
--- a/crates/factor-sqlite/Cargo.toml
+++ b/crates/factor-sqlite/Cargo.toml
@@ -11,7 +11,7 @@ rust-version.workspace = true
 [dependencies]
 async-trait = { workspace = true }
 spin-factors = { path = "../factors" }
-spin-locked-app = { path = "../locked-app" }
+spin-app = { path = "../app" }
 spin-resource-table = { path = "../table" }
 spin-world = { path = "../world" }
 tokio = { workspace = true }
diff --git a/crates/factor-sqlite/src/lib.rs b/crates/factor-sqlite/src/lib.rs
index 9fafdb796a..833ae756c7 100644
--- a/crates/factor-sqlite/src/lib.rs
+++ b/crates/factor-sqlite/src/lib.rs
@@ -7,8 +7,8 @@ use std::sync::Arc;
 use host::InstanceState;
 
 use async_trait::async_trait;
+use spin_app::MetadataKey;
 use spin_factors::{anyhow, Factor, FactorData};
-use spin_locked_app::MetadataKey;
 use spin_world::spin::sqlite::sqlite as v3;
 use spin_world::v1::sqlite as v1;
 use spin_world::v2::sqlite as v2;
diff --git a/crates/factors-test/Cargo.toml b/crates/factors-test/Cargo.toml
index 80ab8aa655..2333cb3786 100644
--- a/crates/factors-test/Cargo.toml
+++ b/crates/factors-test/Cargo.toml
@@ -11,6 +11,7 @@ spin-loader = { path = "../loader" }
 spin-telemetry = { path = "../telemetry", features = ["testing"] }
 tempfile = { workspace = true }
 toml = { workspace = true }
+tokio = { workspace = true }
 
 [lints]
 workspace = true
diff --git a/crates/loader/Cargo.toml b/crates/loader/Cargo.toml
index 0d85b5f577..a709378d88 100644
--- a/crates/loader/Cargo.toml
+++ b/crates/loader/Cargo.toml
@@ -17,7 +17,7 @@ serde_json = { workspace = true }
 sha2 = { workspace = true }
 spin-common = { path = "../common" }
 spin-expressions = { path = "../expressions" }
-spin-locked-app = { path = "../locked-app" }
+spin-app = { path = "../app" }
 spin-manifest = { path = "../manifest" }
 spin-outbound-networking-config = { path = "../outbound-networking-config" }
 spin-serde = { path = "../serde" }
diff --git a/crates/loader/src/lib.rs b/crates/loader/src/lib.rs
index ea64bac40d..0e8a46581c 100644
--- a/crates/loader/src/lib.rs
+++ b/crates/loader/src/lib.rs
@@ -14,8 +14,8 @@ use std::path::{Path, PathBuf};
 
 use anyhow::{Context, Result};
 use local::LocalLoader;
+use spin_app::locked::LockedApp;
 use spin_common::paths::parent_dir;
-use spin_locked_app::locked::LockedApp;
 
 pub mod cache;
 mod fs;
diff --git a/crates/loader/src/local.rs b/crates/loader/src/local.rs
index 34659fc65b..a662c8111c 100644
--- a/crates/loader/src/local.rs
+++ b/crates/loader/src/local.rs
@@ -3,15 +3,15 @@ use std::path::{Path, PathBuf};
 use anyhow::{anyhow, bail, ensure, Context, Result};
 use futures::{future::try_join_all, StreamExt};
 use reqwest::Url;
-use spin_common::{paths::parent_dir, sloth, ui::quoted_path};
-use spin_expressions::Resolver;
-use spin_locked_app::{
+use spin_app::{
     locked::{
         self, ContentPath, ContentRef, LockedApp, LockedComponent, LockedComponentDependency,
         LockedComponentSource, LockedTrigger,
     },
     values::{ValuesMap, ValuesMapBuilder},
 };
+use spin_common::{paths::parent_dir, sloth, ui::quoted_path};
+use spin_expressions::Resolver;
 use spin_manifest::schema::v2::{self, AppManifest, KebabId, WasiFilesMount};
 use spin_outbound_networking_config::allowed_hosts::{AllowedHostConfig, AllowedHostsConfig};
 use spin_serde::DependencyName;
@@ -114,15 +114,14 @@ impl LocalLoader {
         }))
         .await?;
 
-        let host_requirements = spin_locked_app::values::ValuesMap::new();
+        let host_requirements = spin_app::values::ValuesMap::new();
 
         let mut must_understand = vec![];
         if !host_requirements.is_empty() {
-            must_understand.push(spin_locked_app::locked::MustUnderstand::HostRequirements);
+            must_understand.push(spin_app::locked::MustUnderstand::HostRequirements);
         }
         if components.iter().any(|c| !c.host_requirements.is_empty()) {
-            must_understand
-                .push(spin_locked_app::locked::MustUnderstand::ComponentHostRequirements);
+            must_understand.push(spin_app::locked::MustUnderstand::ComponentHostRequirements);
         }
 
         drop(sloth_guard);
@@ -219,8 +218,8 @@ impl LocalLoader {
         let mut host_requirements = ValuesMapBuilder::new();
         if component_requires_service_chaining {
             host_requirements.string(
-                spin_locked_app::locked::SERVICE_CHAINING_KEY,
-                spin_locked_app::locked::HOST_REQ_REQUIRED,
+                spin_app::locked::SERVICE_CHAINING_KEY,
+                spin_app::locked::HOST_REQ_REQUIRED,
             );
         }
         let host_requirements = host_requirements.build();
diff --git a/crates/locked-app/Cargo.toml b/crates/locked-app/Cargo.toml
deleted file mode 100644
index aa9fe98a13..0000000000
--- a/crates/locked-app/Cargo.toml
+++ /dev/null
@@ -1,14 +0,0 @@
-[package]
-name = "spin-locked-app"
-version = { workspace = true }
-authors = { workspace = true }
-edition = { workspace = true }
-
-[dependencies]
-anyhow = { workspace = true }
-async-trait = { workspace = true }
-itertools = { workspace = true }
-serde = { workspace = true }
-serde_json = { workspace = true }
-spin-serde = { path = "../serde" }
-thiserror = { workspace = true }
diff --git a/crates/locked-app/src/lib.rs b/crates/locked-app/src/lib.rs
deleted file mode 100644
index e94cfcf774..0000000000
--- a/crates/locked-app/src/lib.rs
+++ /dev/null
@@ -1,50 +0,0 @@
-//! Spin internal application interfaces
-//!
-//! This crate contains interfaces to Spin application configuration to be used
-//! by crates that implement Spin execution environments: trigger executors and
-//! host components, in particular.
-
-#![deny(missing_docs)]
-
-pub mod locked;
-mod metadata;
-pub mod values;
-
-pub use async_trait::async_trait;
-pub use locked::Variable;
-pub use metadata::{MetadataExt, MetadataKey};
-
-/// MetadataKey for extracting the application name.
-pub const APP_NAME_KEY: MetadataKey = MetadataKey::new("name");
-/// MetadataKey for extracting the application version.
-pub const APP_VERSION_KEY: MetadataKey = MetadataKey::new("version");
-/// MetadataKey for extracting the application description.
-pub const APP_DESCRIPTION_KEY: MetadataKey = MetadataKey::new("description");
-/// MetadataKey for extracting the OCI image digest.
-pub const OCI_IMAGE_DIGEST_KEY: MetadataKey = MetadataKey::new("oci_image_digest");
-
-/// Type alias for a [`Result`]s with [`Error`].
-pub type Result<T> = std::result::Result<T, Error>;
-
-/// Errors returned by methods in this crate.
-#[derive(Debug, thiserror::Error)]
-pub enum Error {
-    /// An error propagated from the `spin_core` crate.
-    #[error(transparent)]
-    CoreError(anyhow::Error),
-    /// An error from a `DynamicHostComponent`.
-    #[error("host component error: {0:#}")]
-    HostComponentError(#[source] anyhow::Error),
-    /// An error from a `Loader` implementation.
-    #[error(transparent)]
-    LoaderError(anyhow::Error),
-    /// An error indicating missing or unexpected metadata.
-    #[error("metadata error: {0}")]
-    MetadataError(String),
-    /// An error indicating failed JSON (de)serialization.
-    #[error("json error: {0}")]
-    JsonError(#[from] serde_json::Error),
-    /// A validation error that can be presented directly to the user.
-    #[error(transparent)]
-    ValidationError(anyhow::Error),
-}
diff --git a/crates/oci/Cargo.toml b/crates/oci/Cargo.toml
index b4655152d0..10879c314f 100644
--- a/crates/oci/Cargo.toml
+++ b/crates/oci/Cargo.toml
@@ -24,7 +24,7 @@ serde_json = { workspace = true }
 spin-common = { path = "../common" }
 spin-compose = { path = "../compose" }
 spin-loader = { path = "../loader" }
-spin-locked-app = { path = "../locked-app" }
+spin-app = { path = "../app" }
 tempfile = { workspace = true }
 tokio = { workspace = true, features = ["fs"] }
 tokio-util = { version = "0.7", features = ["compat"] }
diff --git a/crates/oci/src/client.rs b/crates/oci/src/client.rs
index 7ec254bf46..5be8119df6 100644
--- a/crates/oci/src/client.rs
+++ b/crates/oci/src/client.rs
@@ -13,13 +13,13 @@ use oci_distribution::{
     token_cache::RegistryTokenType, Reference, RegistryOperation,
 };
 use reqwest::Url;
+use spin_app::locked::{ContentPath, ContentRef, LockedApp, LockedComponent};
 use spin_common::sha256;
 use spin_common::ui::quoted_path;
 use spin_common::url::parse_file_url;
 use spin_compose::ComponentSourceLoaderFs;
 use spin_loader::cache::Cache;
 use spin_loader::FilesMountStrategy;
-use spin_locked_app::locked::{ContentPath, ContentRef, LockedApp, LockedComponent};
 use tokio::fs;
 use walkdir::WalkDir;
 
@@ -835,7 +835,7 @@ fn all_annotations(
     explicit: Option<BTreeMap<String, String>>,
     predefined: InferPredefinedAnnotations,
 ) -> Option<BTreeMap<String, String>> {
-    use spin_locked_app::{MetadataKey, APP_DESCRIPTION_KEY, APP_NAME_KEY, APP_VERSION_KEY};
+    use spin_app::{MetadataKey, APP_DESCRIPTION_KEY, APP_NAME_KEY, APP_VERSION_KEY};
     const APP_AUTHORS_KEY: MetadataKey<Vec<String>> = MetadataKey::new("authors");
 
     if predefined == InferPredefinedAnnotations::None {
@@ -989,7 +989,7 @@ mod test {
 
     #[tokio::test]
     async fn can_assemble_layers() {
-        use spin_locked_app::locked::LockedComponent;
+        use spin_app::locked::LockedComponent;
         use tokio::io::AsyncWriteExt;
 
         let working_dir = tempfile::tempdir().unwrap();
@@ -1353,7 +1353,7 @@ mod test {
     }
 
     fn annotatable_app() -> LockedApp {
-        let mut meta_builder = spin_locked_app::values::ValuesMapBuilder::new();
+        let mut meta_builder = spin_app::values::ValuesMapBuilder::new();
         meta_builder
             .string("name", "this-is-spinal-tap")
             .string("version", "11.11.11")
diff --git a/crates/oci/src/loader.rs b/crates/oci/src/loader.rs
index 0a86f7a0df..813e4f2254 100644
--- a/crates/oci/src/loader.rs
+++ b/crates/oci/src/loader.rs
@@ -3,9 +3,9 @@ use std::path::{Path, PathBuf};
 use anyhow::{anyhow, ensure, Context, Result};
 use oci_distribution::Reference;
 use reqwest::Url;
+use spin_app::locked::{ContentPath, ContentRef, LockedApp, LockedComponent};
 use spin_common::ui::quoted_path;
 use spin_loader::cache::Cache;
-use spin_locked_app::locked::{ContentPath, ContentRef, LockedApp, LockedComponent};
 
 use crate::{Client, ORIGIN_URL_SCHEME};
 
diff --git a/crates/oci/src/validate.rs b/crates/oci/src/validate.rs
index a28ccc3893..07c580ba41 100644
--- a/crates/oci/src/validate.rs
+++ b/crates/oci/src/validate.rs
@@ -1,6 +1,6 @@
 use anyhow::{bail, Context, Result};
+use spin_app::locked::{LockedComponent, LockedComponentSource};
 use spin_common::{ui::quoted_path, url::parse_file_url};
-use spin_locked_app::locked::{LockedComponent, LockedComponentSource};
 
 /// Validate that all Spin components specify valid wasm binaries in both the `source`
 /// field and for each dependency.
@@ -56,7 +56,7 @@ async fn read_component_source(source: &LockedComponentSource) -> Result<Vec<u8>
 mod test {
     use super::*;
     use crate::from_json;
-    use spin_locked_app::locked::LockedComponent;
+    use spin_app::locked::LockedComponent;
     use tokio::io::AsyncWriteExt;
 
     #[tokio::test]
diff --git a/examples/spin-timer/Cargo.lock b/examples/spin-timer/Cargo.lock
index 94a0f84724..90cda35456 100644
--- a/examples/spin-timer/Cargo.lock
+++ b/examples/spin-timer/Cargo.lock
@@ -4740,9 +4740,11 @@ name = "spin-app"
 version = "3.4.0-pre0"
 dependencies = [
  "anyhow",
+ "itertools 0.14.0",
  "serde",
  "serde_json",
- "spin-locked-app",
+ "spin-serde",
+ "thiserror 2.0.12",
 ]
 
 [[package]]
@@ -4804,7 +4806,7 @@ dependencies = [
  "anyhow",
  "async-trait",
  "futures",
- "spin-locked-app",
+ "spin-app",
  "thiserror 2.0.12",
 ]
 
@@ -4814,9 +4816,9 @@ version = "3.4.0-pre0"
 dependencies = [
  "anyhow",
  "serde",
+ "spin-app",
  "spin-core",
  "spin-factors",
- "spin-locked-app",
  "spin-resource-table",
  "spin-telemetry",
  "spin-world",
@@ -4833,9 +4835,9 @@ dependencies = [
  "anyhow",
  "async-trait",
  "serde",
+ "spin-app",
  "spin-factors",
  "spin-llm-remote-http",
- "spin-locked-app",
  "spin-telemetry",
  "spin-world",
  "tokio",
@@ -4911,10 +4913,10 @@ dependencies = [
  "rustls 0.23.25",
  "rustls-pki-types",
  "serde",
+ "spin-app",
  "spin-factor-variables",
  "spin-factor-wasi",
  "spin-factors",
- "spin-locked-app",
  "spin-manifest",
  "spin-outbound-networking-config",
  "spin-serde",
@@ -4967,8 +4969,8 @@ name = "spin-factor-sqlite"
 version = "3.4.0-pre0"
 dependencies = [
  "async-trait",
+ "spin-app",
  "spin-factors",
- "spin-locked-app",
  "spin-resource-table",
  "spin-world",
  "tokio",
@@ -5099,19 +5101,6 @@ dependencies = [
  "tracing",
 ]
 
-[[package]]
-name = "spin-locked-app"
-version = "3.4.0-pre0"
-dependencies = [
- "anyhow",
- "async-trait",
- "itertools 0.14.0",
- "serde",
- "serde_json",
- "spin-serde",
- "thiserror 2.0.12",
-]
-
 [[package]]
 name = "spin-manifest"
 version = "3.4.0-pre0"
diff --git a/src/commands/up/app_source.rs b/src/commands/up/app_source.rs
index 29088f0ddd..102b9261a4 100644
--- a/src/commands/up/app_source.rs
+++ b/src/commands/up/app_source.rs
@@ -3,8 +3,8 @@ use std::{
     path::{Path, PathBuf},
 };
 
+use spin_app::locked::LockedApp;
 use spin_common::ui::quoted_path;
-use spin_locked_app::locked::LockedApp;
 use spin_manifest::schema::v2::AppManifest;
 
 /// A source from which an App may be loaded.