diff --git a/Cargo.lock b/Cargo.lock
index 5f17717..9a40033 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3778,7 +3778,7 @@ dependencies = [
 [[package]]
 name = "schematic"
 version = "0.18.12"
-source = "git+https://github.com/JeanMertz/schematic?branch=merged#f072ccf7402d00c853b23712910f22a32cc6bfe3"
+source = "git+https://github.com/JeanMertz/schematic?branch=merged#533dc9ada5af11a74f44adfe19d7c056a174db32"
 dependencies = [
  "indexmap",
  "miette",
@@ -3797,7 +3797,7 @@ dependencies = [
 [[package]]
 name = "schematic_macros"
 version = "0.18.11"
-source = "git+https://github.com/JeanMertz/schematic?branch=merged#f072ccf7402d00c853b23712910f22a32cc6bfe3"
+source = "git+https://github.com/JeanMertz/schematic?branch=merged#533dc9ada5af11a74f44adfe19d7c056a174db32"
 dependencies = [
  "convert_case 0.8.0",
  "darling 0.21.3",
@@ -3809,7 +3809,7 @@ dependencies = [
 [[package]]
 name = "schematic_types"
 version = "0.10.6"
-source = "git+https://github.com/JeanMertz/schematic?branch=merged#f072ccf7402d00c853b23712910f22a32cc6bfe3"
+source = "git+https://github.com/JeanMertz/schematic?branch=merged#533dc9ada5af11a74f44adfe19d7c056a174db32"
 dependencies = [
  "indexmap",
  "relative-path",
diff --git a/crates/jp_cli/src/cmd/attachment/rm.rs b/crates/jp_cli/src/cmd/attachment/rm.rs
index 3b95488..d6381ed 100644
--- a/crates/jp_cli/src/cmd/attachment/rm.rs
+++ b/crates/jp_cli/src/cmd/attachment/rm.rs
@@ -33,7 +33,7 @@ impl IntoPartialAppConfig for Rm {
             .collect::<Result<Vec<_>, _>>()?;
 
         for attachment in partial.conversation.attachments {
-            let url = AttachmentConfig::from_partial(attachment.clone())?.to_url()?;
+            let url = AttachmentConfig::from_partial(attachment.clone(), vec![])?.to_url()?;
             if !to_remove_attachments.contains(&url) {
                 attachments.push(attachment);
             }
diff --git a/crates/jp_cli/src/cmd/conversation/fork.rs b/crates/jp_cli/src/cmd/conversation/fork.rs
index d6a4762..24abd0c 100644
--- a/crates/jp_cli/src/cmd/conversation/fork.rs
+++ b/crates/jp_cli/src/cmd/conversation/fork.rs
@@ -88,11 +88,7 @@ mod tests {
     use std::panic::{AssertUnwindSafe, catch_unwind, resume_unwind};
 
     use assert_matches::assert_matches;
-    use jp_config::{
-        AppConfig, Config as _, PartialAppConfig,
-        conversation::tool::RunMode,
-        model::id::{PartialModelIdConfig, ProviderId},
-    };
+    use jp_config::AppConfig;
     use jp_conversation::{
         Conversation, ConversationEvent, ConversationStream,
         event::{ChatRequest, ChatResponse},
@@ -406,15 +402,7 @@ mod tests {
         for (name, case) in cases {
             let tmp = tempdir().unwrap();
 
-            let mut partial = PartialAppConfig::empty();
-            partial.conversation.tools.defaults.run = Some(RunMode::Ask);
-            partial.assistant.model.id = PartialModelIdConfig {
-                provider: Some(ProviderId::Anthropic),
-                name: Some("test".parse().unwrap()),
-            }
-            .into();
-
-            let config = AppConfig::from_partial(partial).unwrap();
+            let config = AppConfig::new_test();
             let workspace = Workspace::new(tmp.path());
             let mut ctx = Ctx::new(
                 workspace,
diff --git a/crates/jp_config/src/conversation/attachment.rs b/crates/jp_config/src/conversation/attachment.rs
index acf4d34..95bc77d 100644
--- a/crates/jp_config/src/conversation/attachment.rs
+++ b/crates/jp_config/src/conversation/attachment.rs
@@ -74,7 +74,7 @@ impl FromStr for AttachmentConfig {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let partial = PartialAttachmentConfig::from_str(s)?;
-        Self::from_partial(partial).map_err(Into::into)
+        Self::from_partial(partial, vec![]).map_err(Into::into)
     }
 }
 
diff --git a/crates/jp_config/src/conversation/tool.rs b/crates/jp_config/src/conversation/tool.rs
index 246c053..83b2650 100644
--- a/crates/jp_config/src/conversation/tool.rs
+++ b/crates/jp_config/src/conversation/tool.rs
@@ -1049,7 +1049,7 @@ mod tests {
             ))
         );
 
-        let cfg = CommandConfigOrString::from_partial(p.command.clone().unwrap()).unwrap();
+        let cfg = CommandConfigOrString::from_partial(p.command.clone().unwrap(), vec![]).unwrap();
         assert_eq!(cfg.command(), ToolCommandConfig {
             program: "cargo".to_owned(),
             args: vec!["check".to_owned()],
@@ -1073,7 +1073,7 @@ mod tests {
             ))
         );
 
-        let cfg = CommandConfigOrString::from_partial(p.command.unwrap()).unwrap();
+        let cfg = CommandConfigOrString::from_partial(p.command.unwrap(), vec![]).unwrap();
         assert_eq!(cfg.command(), ToolCommandConfig {
             program: "cargo".to_owned(),
             args: vec!["check".to_owned(), "--verbose".to_owned()],
diff --git a/crates/jp_config/src/lib.rs b/crates/jp_config/src/lib.rs
index 4606a97..7ef0dbd 100644
--- a/crates/jp_config/src/lib.rs
+++ b/crates/jp_config/src/lib.rs
@@ -237,6 +237,31 @@ impl ToPartial for AppConfig {
 }
 
 impl AppConfig {
+    /// Return a default configuration for testing purposes.
+    ///
+    /// This CANNOT be used in release mode.
+    #[cfg(debug_assertions)]
+    #[doc(hidden)]
+    #[must_use]
+    pub fn new_test() -> Self {
+        use crate::{
+            conversation::tool::RunMode,
+            model::id::{Name, PartialModelIdConfig, ProviderId},
+        };
+
+        let mut partial = PartialAppConfig::empty();
+
+        partial.conversation.title.generate.auto = Some(false);
+        partial.conversation.tools.defaults.run = Some(RunMode::Ask);
+        partial.assistant.model.id = PartialModelIdConfig {
+            provider: Some(ProviderId::Anthropic),
+            name: Some(Name("test".to_owned())),
+        }
+        .into();
+
+        Self::from_partial(partial, vec![]).expect("valid config")
+    }
+
     /// Return a list of all fields in the configuration.
     ///
     /// The fields are returned in alphabetical order, with nested fields
diff --git a/crates/jp_config/src/model/parameters.rs b/crates/jp_config/src/model/parameters.rs
index ce3dd16..322fc23 100644
--- a/crates/jp_config/src/model/parameters.rs
+++ b/crates/jp_config/src/model/parameters.rs
@@ -207,7 +207,7 @@ impl FromStr for ReasoningConfig {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let partial = PartialReasoningConfig::from_str(s)?;
-        Self::from_partial(partial).map_err(Into::into)
+        Self::from_partial(partial, vec![]).map_err(Into::into)
     }
 }
 
diff --git a/crates/jp_config/src/util.rs b/crates/jp_config/src/util.rs
index 2e3059b..d4b5478 100644
--- a/crates/jp_config/src/util.rs
+++ b/crates/jp_config/src/util.rs
@@ -182,7 +182,7 @@ pub fn build(mut partial: PartialAppConfig) -> Result<AppConfig, Error> {
         "Configuration details."
     );
 
-    let mut config: AppConfig = Config::from_partial(partial)?;
+    let mut config: AppConfig = Config::from_partial(partial, vec![])?;
 
     // Sort instructions by position.
     config
@@ -510,7 +510,7 @@ mod tests {
         let error = build(PartialAppConfig::default_values(&()).unwrap().unwrap()).unwrap_err();
         assert_matches!(
             error,
-            Error::Schematic(schematic::ConfigError::MissingRequired(_))
+            Error::Schematic(schematic::ConfigError::MissingRequired { .. })
         );
 
         let mut partial = PartialAppConfig::default_values(&()).unwrap().unwrap();
@@ -536,7 +536,7 @@ mod tests {
         let mut partial = PartialAppConfig::default_values(&()).unwrap().unwrap();
 
         let error = build(partial.clone()).unwrap_err();
-        assert_matches!(error, Error::Schematic(MissingRequired(v)) if v == "provider");
+        assert_matches!(error, Error::Schematic(MissingRequired { fields }) if fields == vec!["assistant", "model", "id", "provider"]);
         partial.assistant.model.id = PartialModelIdConfig {
             provider: Some(ProviderId::Openrouter),
             name: Some("foo".parse().unwrap()),
@@ -544,7 +544,7 @@ mod tests {
         .into();
 
         let error = build(partial.clone()).unwrap_err();
-        assert_matches!(error, Error::Schematic(MissingRequired(v)) if v == "run");
+        assert_matches!(error, Error::Schematic(MissingRequired{ fields }) if fields == vec!["conversation", "tools", "defaults", "run"]);
         partial.conversation.tools.defaults.run = Some(RunMode::Unattended);
 
         build(partial).unwrap();
diff --git a/crates/jp_conversation/src/stream.rs b/crates/jp_conversation/src/stream.rs
index 303b1f0..dd07581 100644
--- a/crates/jp_conversation/src/stream.rs
+++ b/crates/jp_conversation/src/stream.rs
@@ -209,7 +209,7 @@ impl ConversationStream {
             partial.merge(&(), delta.into())?;
         }
 
-        AppConfig::from_partial(partial).map_err(Into::into)
+        AppConfig::from_partial(partial, vec![]).map_err(Into::into)
     }
 
     /// Removes all events from the end of the stream, until a [`ChatRequest`]
@@ -470,6 +470,22 @@ impl ConversationStream {
             front_config: self.base_config.to_partial(),
         }
     }
+
+    /// Return a default conversation stream for testing purposes.
+    ///
+    /// This CANNOT be used in release mode.
+    #[cfg(debug_assertions)]
+    #[doc(hidden)]
+    #[must_use]
+    pub fn new_test() -> Self {
+        use time::macros::utc_datetime;
+
+        Self {
+            base_config: AppConfig::new_test().into(),
+            events: vec![],
+            created_at: utc_datetime!(2020-01-01 0:00),
+        }
+    }
 }
 
 impl Extend<ConversationEventWithConfig> for ConversationStream {
@@ -748,7 +764,7 @@ impl FromIterator<ConversationEventWithConfig> for Result<ConversationStream, St
             return Err(StreamError::FromEmptyIterator);
         };
 
-        let mut stream = ConversationStream::new(AppConfig::from_partial(config)?.into());
+        let mut stream = ConversationStream::new(AppConfig::from_partial(config, vec![])?.into());
         stream.push(first_event);
         stream.extend(events);
 
@@ -829,7 +845,7 @@ impl<'de> Deserialize<'de> for ConversationStream {
         match events.remove(0) {
             InternalEvent::ConfigDelta(base_config) => Ok(Self {
                 created_at: base_config.timestamp,
-                base_config: AppConfig::from_partial(base_config.into())
+                base_config: AppConfig::from_partial(base_config.into(), vec![])
                     .map_err(Error::custom)?
                     .into(),
                 events,
@@ -988,30 +1004,13 @@ impl<'de> Deserialize<'de> for InternalEvent {
 
 #[cfg(test)]
 mod tests {
-    use jp_config::{
-        conversation::tool::RunMode,
-        model::id::{PartialModelIdConfig, ProviderId},
-    };
     use time::macros::utc_datetime;
 
     use super::*;
 
     #[test]
     fn test_conversation_stream_serialization_roundtrip() {
-        let mut base_config = PartialAppConfig::empty();
-        base_config.conversation.title.generate.auto = Some(false);
-        base_config.conversation.tools.defaults.run = Some(RunMode::Ask);
-        base_config.assistant.model.id = PartialModelIdConfig {
-            provider: Some(ProviderId::Anthropic),
-            name: Some("test".parse().unwrap()),
-        }
-        .into();
-
-        let mut stream = ConversationStream {
-            base_config: AppConfig::from_partial(base_config).unwrap().into(),
-            events: vec![],
-            created_at: utc_datetime!(2020-01-01 0:00),
-        };
+        let mut stream = ConversationStream::new_test();
 
         insta::assert_json_snapshot!(&stream);
 
diff --git a/crates/jp_llm/src/test.rs b/crates/jp_llm/src/test.rs
index f0d8f1d..2c60ef5 100644
--- a/crates/jp_llm/src/test.rs
+++ b/crates/jp_llm/src/test.rs
@@ -97,7 +97,7 @@ impl TestRequest {
                             }
                             .into();
 
-                            AppConfig::from_partial(cfg).unwrap().into()
+                            AppConfig::from_partial(cfg, vec![]).unwrap().into()
                         })
                         .with_created_at(utc_datetime!(2020-01-01 0:00)),
                     )
@@ -128,7 +128,7 @@ impl TestRequest {
                             }
                             .into();
 
-                            AppConfig::from_partial(cfg).unwrap().into()
+                            AppConfig::from_partial(cfg, vec![]).unwrap().into()
                         })
                         .with_created_at(datetime!(2020-01-01 0:00 utc)),
                     )
diff --git a/crates/jp_workspace/src/lib.rs b/crates/jp_workspace/src/lib.rs
index ed64a89..d2c117d 100644
--- a/crates/jp_workspace/src/lib.rs
+++ b/crates/jp_workspace/src/lib.rs
@@ -627,11 +627,6 @@ pub fn user_data_dir() -> Result<PathBuf> {
 mod tests {
     use std::{collections::HashMap, fs, time::Duration};
 
-    use jp_config::{
-        Config as _, PartialAppConfig,
-        conversation::tool::RunMode,
-        model::id::{PartialModelIdConfig, ProviderId},
-    };
     use jp_storage::{CONVERSATIONS_DIR, METADATA_FILE, value::read_json};
     use tempfile::tempdir;
     use test_log::test;
@@ -738,19 +733,9 @@ mod tests {
         let storage = root.join("storage");
 
         let mut workspace = Workspace::new(&root);
+        let config = AppConfig::new_test();
 
-        let mut partial = PartialAppConfig::empty();
-        partial.conversation.tools.defaults.run = Some(RunMode::Ask);
-        partial.assistant.model.id = PartialModelIdConfig {
-            provider: Some(ProviderId::Anthropic),
-            name: Some("test".parse().unwrap()),
-        }
-        .into();
-
-        let id = workspace.create_conversation(
-            Conversation::default(),
-            AppConfig::from_partial(partial).unwrap().into(),
-        );
+        let id = workspace.create_conversation(Conversation::default(), config.into());
         workspace
             .set_active_conversation_id(id, UtcDateTime::UNIX_EPOCH)
             .unwrap();
@@ -818,18 +803,9 @@ mod tests {
         assert!(workspace.state.local.conversations.is_empty());
 
         let conversation = Conversation::default();
-        let mut partial = PartialAppConfig::empty();
-        partial.conversation.tools.defaults.run = Some(RunMode::Ask);
-        partial.assistant.model.id = PartialModelIdConfig {
-            provider: Some(ProviderId::Anthropic),
-            name: Some("test".parse().unwrap()),
-        }
-        .into();
+        let config = AppConfig::new_test();
+        let id = workspace.create_conversation(conversation.clone(), config.into());
 
-        let id = workspace.create_conversation(
-            conversation.clone(),
-            AppConfig::from_partial(partial).unwrap().into(),
-        );
         assert_eq!(
             workspace
                 .state