[Rust Frontend] Add Olmo3 tool parser

rust/src/chat/src/lib.rs

@@ -405,7 +405,7 @@ mod tests {
         )
         .unwrap_err();
 
-        expect_test::expect!["tool parser `definitely_missing_tool_parser` is not registered (choose from: deepseek_v3, deepseek_v31, deepseek_v32, deepseek_v4, gemma4, glm45, glm47, granite4, hermes, hy_v3, hy_v4, inkling, internlm, kimi_k2, kimi_k3, llama3_json, llama4_json, minimax_m2, minimax_m3, mistral, phi4_mini_json, qwen3_coder, qwen3_xml, seed_oss)"].assert_eq(&error.to_report_string());
+        expect_test::expect!["tool parser `definitely_missing_tool_parser` is not registered (choose from: deepseek_v3, deepseek_v31, deepseek_v32, deepseek_v4, gemma4, glm45, glm47, granite4, hermes, hy_v3, hy_v4, inkling, internlm, kimi_k2, kimi_k3, llama3_json, llama4_json, minimax_m2, minimax_m3, mistral, olmo3, phi4_mini_json, qwen3_coder, qwen3_xml, seed_oss)"].assert_eq(&error.to_report_string());
     }
 
     #[test]

rust/src/chat/src/parser/tool/mod.rs

@@ -9,8 +9,8 @@ pub use vllm_parser::tool::{
     DeepSeekV3ToolParser, DeepSeekV4ToolParser, DeepSeekV31ToolParser, DeepSeekV32ToolParser,
     Glm45MoeToolParser, Glm47MoeToolParser, Granite4ToolParser, HermesToolParser,
     Internlm2ToolParser, KimiK2ToolParser, Llama3JsonToolParser, MinimaxM2ToolParser,
-    MinimaxM3ToolParser, MistralToolParser, Phi4MiniJsonToolParser, Qwen3CoderToolParser,
-    Qwen3XmlToolParser, SeedOssToolParser, ToolParser, ToolParserError,
+    MinimaxM3ToolParser, MistralToolParser, Olmo3ToolParser, Phi4MiniJsonToolParser,
+    Qwen3CoderToolParser, Qwen3XmlToolParser, SeedOssToolParser, ToolParser, ToolParserError,
 };
 
 use crate::parser::ParserFactory;
@@ -40,6 +40,7 @@ pub mod names {
     pub const MINIMAX_M2: &str = "minimax_m2";
     pub const MINIMAX_M3: &str = "minimax_m3";
     pub const MISTRAL: &str = "mistral";
+    pub const OLMO3: &str = "olmo3";
     pub const PHI4_MINI_JSON: &str = "phi4_mini_json";
     pub const QWEN3_CODER: &str = "qwen3_coder";
     pub const QWEN3_XML: &str = "qwen3_xml";
@@ -87,12 +88,15 @@ impl ToolParserFactory {
             .register_parser::<MinimaxM2ToolParser>(names::MINIMAX_M2)
             .register_parser::<MinimaxM3ToolParser>(names::MINIMAX_M3)
             .register_parser::<MistralToolParser>(names::MISTRAL)
+            .register_parser::<Olmo3ToolParser>(names::OLMO3)
             .register_parser::<Phi4MiniJsonToolParser>(names::PHI4_MINI_JSON)
             .register_parser::<Qwen3XmlToolParser>(names::QWEN3_XML)
             .register_parser::<Qwen3CoderToolParser>(names::QWEN3_CODER)
             .register_parser::<SeedOssToolParser>(names::SEED_OSS);
 
         factory
+            .register_pattern("olmo-3", names::OLMO3)
+            .register_pattern("olmo3", names::OLMO3)
             .register_pattern("mistral-", names::MISTRAL)
             .register_pattern("mixtral-", names::MISTRAL)
             .register_pattern("qwen3-coder", names::QWEN3_CODER)

rust/src/chat/src/parser/tool/tests.rs

@@ -207,6 +207,10 @@ fn factory_new_resolves_default_patterns() {
         factory.resolve_name_for_model("ByteDance-Seed/Seed-OSS-36B-Instruct"),
         Some(names::SEED_OSS)
     );
+    assert_eq!(
+        factory.resolve_name_for_model("allenai/Olmo-3-7B-Instruct"),
+        Some(names::OLMO3)
+    );
 
     // InternLM2 positive: both dashed and underscored versioned names route.
     assert_eq!(

rust/src/chat/tests/roundtrip.rs

@@ -167,6 +167,19 @@ impl RoundtripCase {
         }
     }
 
+    /// Olmo 3 newline-separated Python-style function calls.
+    fn olmo3() -> Self {
+        Self {
+            model_id: "allenai/Olmo-3-7B-Instruct",
+            assistant_stop_suffix: "<|endoftext|>",
+            tool_call_parser: ParserSelection::Auto,
+            reasoning_parser: ParserSelection::None,
+            thinking_behavior: ThinkingBehavior::Always { value: false },
+            json_fmt: compact_json_fmt(),
+            sort_json_keys: false,
+        }
+    }
+
     /// DeepSeek V4 DSML tool-call format.
     fn deepseek_v4() -> Self {
         Self {
@@ -384,6 +397,7 @@ roundtrip_tests! {
     qwen35 => [reasoning_and_content, tool_call_mix],
     minimax_m25 => [reasoning_and_content, tool_call_mix],
     minimax_m3 => [reasoning_and_content, tool_call_mix],
+    olmo3 => [tool_calls_only],
     deepseek_v4 => [reasoning_and_content, tool_call_mix],
     deepseek_v32 => [tool_call_mix],
     glm45 => [reasoning_and_content, tool_call_mix],
@@ -539,6 +553,71 @@ async fn run_roundtrip_tool_call_mix(
     Ok(())
 }
 
+/// Run the fixed content+multiple-tools fixture for models without reasoning.
+async fn run_roundtrip_tool_calls_only(
+    case: &RoundtripCase,
+    backends: &vllm_chat::LoadedModelBackends,
+) -> Result<()> {
+    let request = roundtrip_request(
+        "roundtrip-tools-only",
+        vec![ChatMessage::text(
+            ChatRole::User,
+            "Check Shanghai weather and add 1.0 plus 2.",
+        )],
+        test_tools(),
+        Some(false),
+        case.thinking_behavior,
+    );
+    let expected_text = "I will call the tools.";
+
+    let result = run_roundtrip(
+        case,
+        backends,
+        &request,
+        AssistantMessage {
+            content: vec![
+                AssistantContentBlock::Text {
+                    text: expected_text.to_string(),
+                },
+                AssistantContentBlock::ToolCall(AssistantToolCall {
+                    id: "functions.get_weather:0".to_string(),
+                    name: "get_weather".to_string(),
+                    arguments: r#"{"location":"Shanghai"}"#.to_string(),
+                }),
+                AssistantContentBlock::ToolCall(AssistantToolCall {
+                    id: "functions.add:1".to_string(),
+                    name: "add".to_string(),
+                    arguments: r#"{"y":1.0,"x":2,"items":["left","right"]}"#.to_string(),
+                }),
+            ],
+        },
+    )
+    .await?;
+
+    assert!(result.parsed_message.reasoning().is_none());
+    assert_eq!(result.parsed_message.text().trim(), expected_text);
+
+    let tool_calls = result.parsed_message.tool_calls().collect::<Vec<_>>();
+    assert_eq!(tool_calls.len(), 2);
+    assert_eq!(tool_calls[0].name, "get_weather");
+    assert_eq!(
+        tool_calls[0].arguments,
+        expected_arguments(case, r#"{"location": "Shanghai"}"#)?,
+    );
+    assert_eq!(tool_calls[1].name, "add");
+    assert_eq!(
+        tool_calls[1].arguments,
+        expected_arguments(case, r#"{"y": 1.0, "x": 2, "items": ["left", "right"]}"#)?,
+    );
+
+    assert_eq!(
+        result.rerendered_closed_completion,
+        result.closed_completion
+    );
+
+    Ok(())
+}
+
 /// Compact JSON argument formatting used by JSON-native parsers/renderers.
 fn compact_json_fmt() -> JsonFmt {
     JsonFmt::new()

rust/src/parser/src/tool/mod.rs

@@ -13,6 +13,7 @@ pub(crate) mod json;
 mod kimi_k2;
 mod minimax_m2;
 mod minimax_m3;
+mod olmo3;
 mod parameters;
 mod qwen_coder;
 mod seed_oss;
@@ -32,6 +33,7 @@ pub use json::{
 pub use kimi_k2::KimiK2ToolParser;
 pub use minimax_m2::MinimaxM2ToolParser;
 pub use minimax_m3::MinimaxM3ToolParser;
+pub use olmo3::Olmo3ToolParser;
 pub use qwen_coder::Qwen3CoderToolParser;
 pub use seed_oss::SeedOssToolParser;
 use serde::{Deserialize, Serialize};