ci: add clippy step and fix clippy warnings

.github/workflows/ci.yml

@@ -20,3 +20,6 @@ jobs:
 
       - name: Check formatting
         run: cargo fmt --all -- --check
+
+      - name: Clippy
+        run: cargo clippy --all-targets --all-features -- -D warnings

crates/langgraph-checkpoint-sqlite/src/saver.rs

@@ -20,6 +20,9 @@ use langgraph_checkpoint::serde::jsonplus::JsonPlusSerializer;
 
 use crate::queries::*;
 
+/// A dumped blob row: (thread_id, checkpoint_ns, channel, type, checkpoint_id, data)
+type BlobDumpRow = (String, String, String, String, String, Option<Vec<u8>>);
+
 /// Async SQLite checkpoint saver using sqlx.
 ///
 /// Uses a three-table schema (`checkpoints`, `checkpoint_blobs`,
@@ -218,7 +221,7 @@ impl SqliteSaver {
         checkpoint_ns: &str,
         values: &HashMap<String, JsonValue>,
         versions: &ChannelVersions,
-    ) -> Vec<(String, String, String, String, String, Option<Vec<u8>>)> {
+    ) -> Vec<BlobDumpRow> {
         let mut result = Vec::new();
         for (channel, ver) in versions {
             let ver_str = match ver {

crates/langgraph-checkpoint/src/cache/memory.rs

@@ -5,10 +5,12 @@ use parking_lot::RwLock;
 use serde_json::Value as JsonValue;
 use std::collections::HashMap;
 
+/// namespace -> key -> (type_tag, bytes, expire_at_unix_secs)
+type CacheMap = HashMap<CacheNamespace, HashMap<String, (String, Vec<u8>, Option<f64>)>>;
+
 /// In-memory cache implementation
 pub struct InMemoryCache {
-    /// namespace -> key -> (type_tag, bytes, expire_at_unix_secs)
-    cache: RwLock<HashMap<CacheNamespace, HashMap<String, (String, Vec<u8>, Option<f64>)>>>,
+    cache: RwLock<CacheMap>,
 }
 
 impl InMemoryCache {
@@ -127,7 +129,7 @@ mod tests {
         cache
             .set(&[((ns.clone(), "k1".to_string()), serde_json::json!(1), None)])
             .unwrap();
-        cache.clear(Some(&[ns.clone()])).unwrap();
+        cache.clear(Some(std::slice::from_ref(&ns))).unwrap();
         let result = cache.get(&[(ns, "k1".to_string())]).unwrap();
         assert!(result.is_empty());
     }

crates/langgraph-checkpoint/src/checkpoint/memory.rs

@@ -10,15 +10,18 @@ use std::collections::HashMap;
 type StorageKey = (String, String, String); // (thread_id, checkpoint_ns, checkpoint_id)
 type WriteKey = (String, String, String, i64); // (thread_id, checkpoint_ns, checkpoint_id, idx)
 
+/// (thread_id, checkpoint_ns, checkpoint_id) -> (checkpoint_json, metadata_json, parent_checkpoint_id)
+type StorageValue = (JsonValue, JsonValue, Option<String>);
+/// (thread_id, checkpoint_ns, checkpoint_id, idx) -> (task_id, channel, value_json, task_path)
+type WriteValue = (String, String, JsonValue, String);
+
 /// In-memory checkpoint saver for testing and development.
 ///
 /// Stores checkpoints, blobs, and writes in memory using DashMap
 /// for concurrent access.
 pub struct InMemorySaver {
-    // (thread_id, checkpoint_ns, checkpoint_id) -> (checkpoint_json, metadata_json, parent_checkpoint_id)
-    storage: RwLock<HashMap<StorageKey, (JsonValue, JsonValue, Option<String>)>>,
-    // (thread_id, checkpoint_ns, checkpoint_id, idx) -> (task_id, channel, value_json, task_path)
-    writes: RwLock<HashMap<WriteKey, (String, String, JsonValue, String)>>,
+    storage: RwLock<HashMap<StorageKey, StorageValue>>,
+    writes: RwLock<HashMap<WriteKey, WriteValue>>,
 }
 
 impl InMemorySaver {

crates/langgraph-checkpoint/src/store/memory.rs

@@ -186,7 +186,7 @@ impl BaseStore for InMemoryStore {
                         }
                     }
 
-                    items.sort_by(|a, b| b.updated_at.cmp(&a.updated_at));
+                    items.sort_by_key(|b| std::cmp::Reverse(b.updated_at));
                     let total = items.len();
                     let start = search_op.offset.min(total);
                     let end = (start + search_op.limit).min(total);

crates/langgraph-core/src/channels/base.rs

@@ -12,6 +12,7 @@ pub trait Channel: Send + Sync + 'static {
     fn checkpoint(&self) -> Option<JsonValue>;
 
     /// Restore channel state from a checkpoint.
+    #[allow(clippy::wrong_self_convention)]
     fn from_checkpoint(&self, checkpoint: Option<&JsonValue>) -> Box<dyn Channel>;
 
     /// Apply a batch of updates. Returns true if the channel was modified.

crates/langgraph-core/src/graph/state.rs

@@ -260,6 +260,7 @@ impl StateGraph {
     }
 
     /// Internal: compile with explicit parameters.
+    #[allow(clippy::too_many_arguments)]
     fn compile_with(
         &mut self,
         checkpointer: Option<Arc<dyn BaseCheckpointSaver>>,
@@ -596,7 +597,7 @@ impl CompiledStateGraph {
             for (tid, chan, val) in pending {
                 if tid == NULL_TASK_ID {
                     if let Some(ch) = channels.get(chan) {
-                        ch.update(&[val.clone()]).ok();
+                        ch.update(std::slice::from_ref(val)).ok();
                     }
                 }
             }
@@ -793,7 +794,7 @@ impl CompiledStateGraph {
         if let Some(obj) = values.as_object() {
             for (key, val) in obj {
                 if let Some(ch) = channels.get(key) {
-                    ch.update(&[val.clone()]).ok();
+                    ch.update(std::slice::from_ref(val)).ok();
                     // Bump the channel version
                     let new_version = channel_versions
                         .get(key)
@@ -883,12 +884,12 @@ impl CompiledStateGraph {
                     }
                     if tid == NULL_TASK_ID {
                         if let Some(ch) = channels.get(chan) {
-                            ch.update(&[val.clone()]).ok();
+                            ch.update(std::slice::from_ref(val)).ok();
                         }
                         continue;
                     }
                     if let Some(ch) = channels.get(chan) {
-                        ch.update(&[val.clone()]).ok();
+                        ch.update(std::slice::from_ref(val)).ok();
                     }
                 }
             }
@@ -1372,7 +1373,7 @@ impl CompiledStateGraph {
                             for (_task_id, channel, value) in pending {
                                 if channel != RESUME {
                                     if let Some(ch) = restored.get(channel) {
-                                        ch.update(&[value.clone()]).ok();
+                                        ch.update(std::slice::from_ref(value)).ok();
                                     }
                                 }
                             }
@@ -1443,14 +1444,14 @@ impl CompiledStateGraph {
             let input_writes = map_input(&[START.to_string()], input);
             for (chan, val) in &input_writes {
                 if let Some(ch) = channels.get(chan) {
-                    ch.update(&[val.clone()]).ok();
+                    ch.update(std::slice::from_ref(val)).ok();
                 }
             }
             if let Some(obj) = input.as_object() {
                 for (key, val) in obj {
                     if key != START && !key.starts_with("branch:") && !key.starts_with("join:") {
                         if let Some(ch) = channels.get(key) {
-                            ch.update(&[val.clone()]).ok();
+                            ch.update(std::slice::from_ref(val)).ok();
                         }
                     }
                 }

crates/langgraph-core/src/pregel/algo.rs

@@ -42,6 +42,7 @@ fn version_gt(a: &JsonValue, b: &JsonValue) -> bool {
 ///
 /// This is the "Plan" phase of the BSP cycle. It checks which nodes
 /// have trigger channels with newer versions than what the node last saw.
+#[allow(clippy::too_many_arguments)]
 pub fn prepare_next_tasks(
     nodes: &HashMap<String, PregelNode>,
     channels: &HashMap<String, Box<dyn Channel>>,
@@ -292,12 +293,10 @@ pub fn apply_writes(
     //    This allows ephemeral channels to clear themselves and notify downstream.
     if bump_step {
         for (chan, ch) in channels.iter() {
-            if ch.is_available() && !updated.contains(chan) {
-                if ch.update(&[]).unwrap_or(false) {
-                    channel_versions.insert(chan.clone(), next_version.clone());
-                    if ch.is_available() {
-                        updated.insert(chan.clone());
-                    }
+            if ch.is_available() && !updated.contains(chan) && ch.update(&[]).unwrap_or(false) {
+                channel_versions.insert(chan.clone(), next_version.clone());
+                if ch.is_available() {
+                    updated.insert(chan.clone());
                 }
             }
         }

crates/langgraph-derive/src/lib.rs

@@ -279,7 +279,7 @@ fn impl_tool_macro(name_lit: &Option<Lit>, desc_lit: &Option<Lit>, func: &ItemFn
                                 continue;
                             }
                             if !extracted_desc.is_empty() {
-                                extracted_desc.push_str(" ");
+                                extracted_desc.push(' ');
                             }
                             extracted_desc.push_str(trimmed);
                         }

crates/langgraph-prebuilt/src/traits.rs

@@ -224,12 +224,15 @@ impl BaseChatModel for Box<dyn BaseChatModel> {
     }
 }
 
+/// A tool function: maps an input JSON value to an output JSON value.
+pub type ToolFn = Box<dyn Fn(&JsonValue) -> Result<JsonValue, ToolError> + Send + Sync>;
+
 /// A simple tool implemented as a closure.
 pub struct ClosureTool {
     tool_name: String,
     tool_description: String,
     tool_parameters: Option<JsonValue>,
-    func: Box<dyn Fn(&JsonValue) -> Result<JsonValue, ToolError> + Send + Sync>,
+    func: ToolFn,
 }
 
 impl ClosureTool {

crates/langgraph-providers/src/anthropic/model.rs

@@ -174,6 +174,7 @@ enum ContentBlockStart {
 
 #[derive(Deserialize)]
 #[serde(tag = "type", rename_all = "snake_case")]
+#[allow(clippy::enum_variant_names)]
 enum ContentBlockDelta {
     TextDelta { text: String },
     InputJsonDelta { partial_json: String },
@@ -687,7 +688,8 @@ impl BaseChatModel for AnthropicModel {
                         "message_stop" => {
                             break;
                         }
-                        "ping" | _ => {}
+                        "ping" => {}
+                        _ => {}
                     }
                 }
             }

crates/langgraph-providers/src/openai/model.rs

@@ -447,17 +447,14 @@ impl OpenAIModel {
         reserved_keys: &[&str],
     ) -> Option<serde_json::Value> {
         let mut extra = extra?;
-        if let Some(obj) = extra.as_object_mut() {
-            for key in reserved_keys {
-                obj.remove(*key);
-            }
-            if obj.is_empty() {
-                return None;
-            }
-            return Some(serde_json::Value::Object(obj.clone()));
-        } else {
+        let obj = extra.as_object_mut()?;
+        for key in reserved_keys {
+            obj.remove(*key);
+        }
+        if obj.is_empty() {
             return None;
         }
+        Some(serde_json::Value::Object(obj.clone()))
     }
 }
 

crates/langgraph-tracing/src/store.rs

@@ -91,7 +91,7 @@ impl TracingStore for InMemoryTracingStore {
             .collect();
 
         // Sort newest first
-        summaries.sort_by(|a, b| b.start_time.cmp(&a.start_time));
+        summaries.sort_by_key(|b| std::cmp::Reverse(b.start_time));
 
         let offset = filter.offset.unwrap_or(0);
         let limit = filter.limit.unwrap_or(summaries.len());

examples/interactive_chat_with_tracing.rs

@@ -7,7 +7,6 @@ use langgraph::prebuilt::{
 use langgraph::prelude::*;
 use langgraph::providers::openai::{OpenAIModel, OpenAIModelConfig};
 use langgraph::{langgraph_state, tool, Traceable};
-use serde::{Deserialize, Serialize};
 use serde_json::{json, Value as JsonValue};
 use std::io::{self, Write};
 use std::sync::Arc;

examples/parallel_interrupt_hitl.rs

@@ -76,7 +76,6 @@ async fn worker_b_node(
 }
 
 /// Output node: triggered only by worker_a's edge.
-
 async fn output_node(
     _input: JsonValue,
     _config: RunnableConfig,