Vakyartha documentation

1#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
2
3use tokio_util::sync::CancellationToken;
4
5use vak_llm::Provider;
6use vak_llm::error::LlmError;
7use vak_llm::google::{GoogleConfig, GoogleProvider, build_body};
8use vak_llm::stream::StreamEvent;
9use vak_llm::types::{ChatRequest, ContentBlock, Message, Role, StopReason, ToolDefinition};
10
11fn sample_request() -> ChatRequest {
12 let mut req = ChatRequest::new("gemini-3-pro");
13 req.system = Some("You are a coding agent.".into());
14 req.messages = vec![
15 Message::user_text("list the files"),
16 Message::assistant(vec![
17 ContentBlock::text("Checking."),
18 ContentBlock::ToolUse {
19 id: "call_abc".into(),
20 name: "bash".into(),
21 input: serde_json::json!({"command": "ls"}),
22 },
23 ]),
24 Message {
25 role: Role::User,
26 content: vec![ContentBlock::tool_result("call_abc", "src\nREADME.md")],
27 },
28 Message::user_text("and now?"),
29 ];
30 req.tools = vec![ToolDefinition::new(
31 "bash",
32 "Run a shell command",
33 serde_json::json!({"type": "object", "properties": {"command": {"type": "string"}}, "required": ["command"]}),
34 )];
35 req
36}
37
38#[test]
39fn body_maps_neutral_history_to_gemini_shape() {
40 let body = build_body(&sample_request()).unwrap();
41 assert_eq!(
42 body["systemInstruction"]["parts"][0]["text"],
43 "You are a coding agent."
44 );
45
46 let contents = body["contents"].as_array().unwrap();
47 // user, model(text+functionCall), user(functionResponse), user(text)
48 assert_eq!(contents.len(), 4);
49
50 assert_eq!(contents[0]["role"], "user");
51 assert_eq!(contents[0]["parts"][0]["text"], "list the files");
52
53 assert_eq!(contents[1]["role"], "model");
54 let parts = contents[1]["parts"].as_array().unwrap();
55 assert_eq!(parts[0]["text"], "Checking.");
56 assert_eq!(parts[1]["functionCall"]["name"], "bash");
57 // Gemini args are OBJECTS, not strings.
58 assert_eq!(
59 parts[1]["functionCall"]["args"],
60 serde_json::json!({"command": "ls"})
61 );
62
63 assert_eq!(contents[2]["role"], "user");
64 let resp_parts = contents[2]["parts"].as_array().unwrap();
65 // functionResponse keyed by NAME resolved from the prior functionCall.
66 assert_eq!(
67 resp_parts[0]["functionResponse"]["name"], "bash",
68 "tool_use_id must resolve to the function name via history"
69 );
70 assert_eq!(
71 resp_parts[0]["functionResponse"]["response"]["result"],
72 "src\nREADME.md"
73 );
74
75 assert_eq!(contents[3]["role"], "user");
76 assert_eq!(contents[3]["parts"][0]["text"], "and now?");
77
78 let decls = body["tools"][0]["functionDeclarations"].as_array().unwrap();
79 assert_eq!(decls[0]["name"], "bash");
80}
81
82const FIXTURE_STREAM: &str = "\
83data: {\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"Read\"}],\"role\":\"model\"}}],\"usageMetadata\":{\"promptTokenCount\":21,\"candidatesTokenCount\":2}}\n\
84\n\
85data: {\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"ing now.\"}],\"role\":\"model\"}}]}\n\
86\n\
87data: {\"candidates\":[{\"content\":{\"parts\":[{\"functionCall\":{\"name\":\"read\",\"args\":{\"path\":\"a.txt\"}},\"thoughtSignature\":\"test_sig_value\"}],\"role\":\"model\"},\"finishReason\":\"STOP\"}],\"usageMetadata\":{\"promptTokenCount\":21,\"candidatesTokenCount\":9}}\n\
88\n";
89
90#[tokio::test]
91async fn full_stream_accumulates_text_and_function_calls() {
92 let provider = GoogleProvider::new(GoogleConfig {
93 api_key: "k".into(),
94 base_url: mock_url(FIXTURE_STREAM).await,
95 })
96 .unwrap();
97
98 let mut es = provider
99 .stream(sample_request(), CancellationToken::new())
100 .await
101 .unwrap();
102 let mut text = String::new();
103 while let Some(ev) = futures::StreamExt::next(&mut es).await {
104 if let StreamEvent::TextDelta { delta, .. } = ev {
105 text.push_str(&delta);
106 }
107 }
108 let msg = es.result().await.unwrap();
109
110 assert_eq!(text, "Reading now.");
111 assert_eq!(msg.stop_reason, StopReason::ToolUse);
112 assert_eq!(msg.usage.input_tokens, 21);
113 assert_eq!(msg.usage.output_tokens, 9);
114
115 let calls: Vec<&ContentBlock> = msg
116 .content
117 .iter()
118 .filter(|b| matches!(b, ContentBlock::ToolUse { .. }))
119 .collect();
120 assert_eq!(calls.len(), 1);
121 if let ContentBlock::ToolUse { name, input, .. } = calls[0] {
122 assert_eq!(name, "read");
123 assert_eq!(input, &serde_json::json!({"path": "a.txt"}));
124 } else {
125 unreachable!()
126 }
127
128 let sigs: Vec<Option<&str>> = msg
129 .content
130 .iter()
131 .filter_map(|b| match b {
132 ContentBlock::Thinking { signature, .. } => Some(signature.as_deref()),
133 _ => None,
134 })
135 .collect();
136 assert_eq!(sigs, vec![Some("test_sig_value")]);
137}
138
139// Realistic cache-bearing usage (docs/design/68-context-engine.md §1):
140// `promptTokenCount` is the whole prompt, `cachedContentTokenCount` a
141// SUBSET of it, not an addition.
142const FIXTURE_CACHED_USAGE: &str = "\
143data: {\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"ok\"}],\"role\":\"model\"},\"finishReason\":\"STOP\"}],\"usageMetadata\":{\"promptTokenCount\":8000,\"candidatesTokenCount\":40,\"cachedContentTokenCount\":7500}}\n\
144\n";
145
146#[tokio::test]
147async fn cached_tokens_are_split_out_of_prompt_token_count_not_added_on_top() {
148 let provider = GoogleProvider::new(GoogleConfig {
149 api_key: "k".into(),
150 base_url: mock_url(FIXTURE_CACHED_USAGE).await,
151 })
152 .unwrap();
153 let mut req = ChatRequest::new("m");
154 req.messages = vec![Message::user_text("hi")];
155 let mut es = provider
156 .stream(req, CancellationToken::new())
157 .await
158 .unwrap();
159 while futures::StreamExt::next(&mut es).await.is_some() {}
160 let msg = es.result().await.unwrap();
161 assert_eq!(msg.usage.input_tokens, 500);
162 assert_eq!(msg.usage.cache_read_input_tokens, Some(7500));
163 assert_eq!(msg.usage.prompt_tokens(), 8000);
164}
165
166const FIXTURE_STOP: &str = "\
167data: {\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"done\"}],\"role\":\"model\"},\"finishReason\":\"STOP\"}],\"usageMetadata\":{\"promptTokenCount\":5,\"candidatesTokenCount\":1}}\n\
168\n";
169
170#[tokio::test]
171async fn finish_stop_maps_to_end_turn() {
172 let provider = GoogleProvider::new(GoogleConfig {
173 api_key: "k".into(),
174 base_url: mock_url(FIXTURE_STOP).await,
175 })
176 .unwrap();
177 let mut req = ChatRequest::new("m");
178 req.messages = vec![Message::user_text("hi")];
179 let mut es = provider
180 .stream(req, CancellationToken::new())
181 .await
182 .unwrap();
183 while futures::StreamExt::next(&mut es).await.is_some() {}
184 let msg = es.result().await.unwrap();
185 assert_eq!(msg.stop_reason, StopReason::EndTurn);
186 assert_eq!(msg.text_content(), "done");
187}
188
189#[tokio::test]
190async fn http_error_maps_to_typed_value() {
191 let url = error_url(429, r#"{"error":{"message":"quota exceeded"}}"#).await;
192 let provider = GoogleProvider::new(GoogleConfig {
193 api_key: "k".into(),
194 base_url: url,
195 })
196 .unwrap();
197 let err = provider
198 .stream(ChatRequest::new("m"), CancellationToken::new())
199 .await
200 .err()
201 .expect("expected error");
202 assert!(matches!(err, LlmError::RateLimit { .. }), "got {err:?}");
203}
204
205async fn spawn_server(body: Vec<u8>) -> String {
206 let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
207 let addr = listener.local_addr().unwrap();
208 tokio::spawn(async move {
209 let (mut sock, _) = listener.accept().await.unwrap();
210 drain_headers(&mut sock).await;
211 use tokio::io::AsyncWriteExt;
212 let _ = sock.write_all(&body).await;
213 let _ = sock.flush().await;
214 let _ = sock.shutdown().await;
215 });
216 format!("http://{addr}")
217}
218
219async fn drain_headers<S>(sock: &mut S)
220where
221 S: tokio::io::AsyncRead + Unpin,
222{
223 use tokio::io::AsyncReadExt;
224 let mut buf = Vec::new();
225 let mut chunk = [0u8; 1024];
226 loop {
227 let n = sock.read(&mut chunk).await.unwrap_or(0);
228 if n == 0 {
229 return;
230 }
231 buf.extend_from_slice(&chunk[..n]);
232 if buf.windows(4).any(|w| w == b"\r\n\r\n") {
233 return;
234 }
235 }
236}
237
238async fn mock_url(sse_body: &str) -> String {
239 let owned = format!(
240 "HTTP/1.1 200 OK\r\ncontent-type: text/event-stream\r\nconnection: close\r\n\r\n{sse_body}"
241 );
242 spawn_server(owned.into_bytes()).await
243}
244
245async fn error_url(status: u16, json: &str) -> String {
246 let owned = format!(
247 "HTTP/1.1 {status} Err\r\ncontent-type: application/json\r\nconnection: close\r\n\r\n{json}"
248 );
249 spawn_server(owned.into_bytes()).await
250}
251
252#[test]
253fn body_sanitizes_unsupported_schema_keywords_for_gemini() {
254 let mut req = ChatRequest::new("gemini-2.5-flash");
255 req.messages = vec![Message::user_text("test")];
256 req.tools = vec![ToolDefinition::new(
257 "complex_tool",
258 "A tool with schema keywords unsupported by Gemini",
259 serde_json::json!({
260 "$schema": "http://json-schema.org/draft-07/schema#",
261 "type": "object",
262 "additionalProperties": false,
263 "properties": {
264 "name": {
265 "type": "string",
266 "description": "The name"
267 },
268 "nested": {
269 "type": "object",
270 "additionalProperties": false,
271 "properties": {
272 "inner": {"type": "string"}
273 }
274 }
275 },
276 "patternProperties": {
277 "^x-": {"type": "string"}
278 },
279 "definitions": {
280 "something": {}
281 }
282 }),
283 )];
284
285 let body = build_body(&req).unwrap();
286 let params = &body["tools"][0]["functionDeclarations"][0]["parameters"];
287 assert!(params.get("$schema").is_none());
288 assert!(params.get("additionalProperties").is_none());
289 assert!(params.get("patternProperties").is_none());
290 assert!(params.get("definitions").is_none());
291 assert!(
292 params["properties"]["nested"]
293 .get("additionalProperties")
294 .is_none()
295 );
296 assert_eq!(params["properties"]["name"]["type"], "string");
297}
298
299#[test]
300fn body_serializes_thought_signature_on_assistant_function_calls() {
301 let mut req = ChatRequest::new("gemini-3.8-flash");
302 req.messages = vec![
303 Message::user_text("what is the weather?"),
304 Message::assistant(vec![
305 ContentBlock::Thinking {
306 text: String::new(),
307 signature: Some("sig_abc_123".into()),
308 },
309 ContentBlock::ToolUse {
310 id: "call_1".into(),
311 name: "get_weather".into(),
312 input: serde_json::json!({"location": "Tokyo"}),
313 },
314 ]),
315 Message {
316 role: Role::User,
317 content: vec![ContentBlock::tool_result("call_1", "Sunny 22C")],
318 },
319 ];
320
321 let body = build_body(&req).unwrap();
322 let contents = body["contents"].as_array().unwrap();
323 assert_eq!(contents.len(), 3);
324 let model_parts = contents[1]["parts"].as_array().unwrap();
325 assert_eq!(model_parts.len(), 1);
326 assert_eq!(model_parts[0]["functionCall"]["name"], "get_weather");
327 assert_eq!(model_parts[0]["thoughtSignature"], "sig_abc_123");
328}
329

1#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
2
3use tokio_util::sync::CancellationToken;
4
5use vak_llm::Provider;
6use vak_llm::error::LlmError;
7use vak_llm::google::{GoogleConfig, GoogleProvider, build_body};
8use vak_llm::stream::StreamEvent;
9use vak_llm::types::{ChatRequest, ContentBlock, Message, Role, StopReason, ToolDefinition};
10
11fn sample_request() -> ChatRequest {
12 let mut req = ChatRequest::new("gemini-3-pro");
13 req.system = Some("You are a coding agent.".into());
14 req.messages = vec![
15 Message::user_text("list the files"),
16 Message::assistant(vec![
17 ContentBlock::text("Checking."),
18 ContentBlock::ToolUse {
19 id: "call_abc".into(),
20 name: "bash".into(),
21 input: serde_json::json!({"command": "ls"}),
22 },
23 ]),
24 Message {
25 role: Role::User,
26 content: vec![ContentBlock::tool_result("call_abc", "src\nREADME.md")],
27 },
28 Message::user_text("and now?"),
29 ];
30 req.tools = vec![ToolDefinition::new(
31 "bash",
32 "Run a shell command",
33 serde_json::json!({"type": "object", "properties": {"command": {"type": "string"}}, "required": ["command"]}),
34 )];
35 req
36}
37
38#[test]
39fn body_maps_neutral_history_to_gemini_shape() {
40 let body = build_body(&sample_request()).unwrap();
41 assert_eq!(
42 body["systemInstruction"]["parts"][0]["text"],
43 "You are a coding agent."
44 );
45
46 let contents = body["contents"].as_array().unwrap();
47 // user, model(text+functionCall), user(functionResponse), user(text)
48 assert_eq!(contents.len(), 4);
49
50 assert_eq!(contents[0]["role"], "user");
51 assert_eq!(contents[0]["parts"][0]["text"], "list the files");
52
53 assert_eq!(contents[1]["role"], "model");
54 let parts = contents[1]["parts"].as_array().unwrap();
55 assert_eq!(parts[0]["text"], "Checking.");
56 assert_eq!(parts[1]["functionCall"]["name"], "bash");
57 // Gemini args are OBJECTS, not strings.
58 assert_eq!(
59 parts[1]["functionCall"]["args"],
60 serde_json::json!({"command": "ls"})
61 );
62
63 assert_eq!(contents[2]["role"], "user");
64 let resp_parts = contents[2]["parts"].as_array().unwrap();
65 // functionResponse keyed by NAME resolved from the prior functionCall.
66 assert_eq!(
67 resp_parts[0]["functionResponse"]["name"], "bash",
68 "tool_use_id must resolve to the function name via history"
69 );
70 assert_eq!(
71 resp_parts[0]["functionResponse"]["response"]["result"],
72 "src\nREADME.md"
73 );
74
75 assert_eq!(contents[3]["role"], "user");
76 assert_eq!(contents[3]["parts"][0]["text"], "and now?");
77
78 let decls = body["tools"][0]["functionDeclarations"].as_array().unwrap();
79 assert_eq!(decls[0]["name"], "bash");
80}
81
82const FIXTURE_STREAM: &str = "\
83data: {\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"Read\"}],\"role\":\"model\"}}],\"usageMetadata\":{\"promptTokenCount\":21,\"candidatesTokenCount\":2}}\n\
84\n\
85data: {\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"ing now.\"}],\"role\":\"model\"}}]}\n\
86\n\
87data: {\"candidates\":[{\"content\":{\"parts\":[{\"functionCall\":{\"name\":\"read\",\"args\":{\"path\":\"a.txt\"}},\"thoughtSignature\":\"test_sig_value\"}],\"role\":\"model\"},\"finishReason\":\"STOP\"}],\"usageMetadata\":{\"promptTokenCount\":21,\"candidatesTokenCount\":9}}\n\
88\n";
89
90#[tokio::test]
91async fn full_stream_accumulates_text_and_function_calls() {
92 let provider = GoogleProvider::new(GoogleConfig {
93 api_key: "k".into(),
94 base_url: mock_url(FIXTURE_STREAM).await,
95 })
96 .unwrap();
97
98 let mut es = provider
99 .stream(sample_request(), CancellationToken::new())
100 .await
101 .unwrap();
102 let mut text = String::new();
103 while let Some(ev) = futures::StreamExt::next(&mut es).await {
104 if let StreamEvent::TextDelta { delta, .. } = ev {
105 text.push_str(&delta);
106 }
107 }
108 let msg = es.result().await.unwrap();
109
110 assert_eq!(text, "Reading now.");
111 assert_eq!(msg.stop_reason, StopReason::ToolUse);
112 assert_eq!(msg.usage.input_tokens, 21);
113 assert_eq!(msg.usage.output_tokens, 9);
114
115 let calls: Vec<&ContentBlock> = msg
116 .content
117 .iter()
118 .filter(|b| matches!(b, ContentBlock::ToolUse { .. }))
119 .collect();
120 assert_eq!(calls.len(), 1);
121 if let ContentBlock::ToolUse { name, input, .. } = calls[0] {
122 assert_eq!(name, "read");
123 assert_eq!(input, &serde_json::json!({"path": "a.txt"}));
124 } else {
125 unreachable!()
126 }
127
128 let sigs: Vec<Option<&str>> = msg
129 .content
130 .iter()
131 .filter_map(|b| match b {
132 ContentBlock::Thinking { signature, .. } => Some(signature.as_deref()),
133 _ => None,
134 })
135 .collect();
136 assert_eq!(sigs, vec![Some("test_sig_value")]);
137}
138
139// Realistic cache-bearing usage (docs/design/68-context-engine.md §1):
140// `promptTokenCount` is the whole prompt, `cachedContentTokenCount` a
141// SUBSET of it, not an addition.
142const FIXTURE_CACHED_USAGE: &str = "\
143data: {\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"ok\"}],\"role\":\"model\"},\"finishReason\":\"STOP\"}],\"usageMetadata\":{\"promptTokenCount\":8000,\"candidatesTokenCount\":40,\"cachedContentTokenCount\":7500}}\n\
144\n";
145
146#[tokio::test]
147async fn cached_tokens_are_split_out_of_prompt_token_count_not_added_on_top() {
148 let provider = GoogleProvider::new(GoogleConfig {
149 api_key: "k".into(),
150 base_url: mock_url(FIXTURE_CACHED_USAGE).await,
151 })
152 .unwrap();
153 let mut req = ChatRequest::new("m");
154 req.messages = vec![Message::user_text("hi")];
155 let mut es = provider
156 .stream(req, CancellationToken::new())
157 .await
158 .unwrap();
159 while futures::StreamExt::next(&mut es).await.is_some() {}
160 let msg = es.result().await.unwrap();
161 assert_eq!(msg.usage.input_tokens, 500);
162 assert_eq!(msg.usage.cache_read_input_tokens, Some(7500));
163 assert_eq!(msg.usage.prompt_tokens(), 8000);
164}
165
166const FIXTURE_STOP: &str = "\
167data: {\"candidates\":[{\"content\":{\"parts\":[{\"text\":\"done\"}],\"role\":\"model\"},\"finishReason\":\"STOP\"}],\"usageMetadata\":{\"promptTokenCount\":5,\"candidatesTokenCount\":1}}\n\
168\n";
169
170#[tokio::test]
171async fn finish_stop_maps_to_end_turn() {
172 let provider = GoogleProvider::new(GoogleConfig {
173 api_key: "k".into(),
174 base_url: mock_url(FIXTURE_STOP).await,
175 })
176 .unwrap();
177 let mut req = ChatRequest::new("m");
178 req.messages = vec![Message::user_text("hi")];
179 let mut es = provider
180 .stream(req, CancellationToken::new())
181 .await
182 .unwrap();
183 while futures::StreamExt::next(&mut es).await.is_some() {}
184 let msg = es.result().await.unwrap();
185 assert_eq!(msg.stop_reason, StopReason::EndTurn);
186 assert_eq!(msg.text_content(), "done");
187}
188
189#[tokio::test]
190async fn http_error_maps_to_typed_value() {
191 let url = error_url(429, r#"{"error":{"message":"quota exceeded"}}"#).await;
192 let provider = GoogleProvider::new(GoogleConfig {
193 api_key: "k".into(),
194 base_url: url,
195 })
196 .unwrap();
197 let err = provider
198 .stream(ChatRequest::new("m"), CancellationToken::new())
199 .await
200 .err()
201 .expect("expected error");
202 assert!(matches!(err, LlmError::RateLimit { .. }), "got {err:?}");
203}
204
205async fn spawn_server(body: Vec<u8>) -> String {
206 let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
207 let addr = listener.local_addr().unwrap();
208 tokio::spawn(async move {
209 let (mut sock, _) = listener.accept().await.unwrap();
210 drain_headers(&mut sock).await;
211 use tokio::io::AsyncWriteExt;
212 let _ = sock.write_all(&body).await;
213 let _ = sock.flush().await;
214 let _ = sock.shutdown().await;
215 });
216 format!("http://{addr}")
217}
218
219async fn drain_headers<S>(sock: &mut S)
220where
221 S: tokio::io::AsyncRead + Unpin,
222{
223 use tokio::io::AsyncReadExt;
224 let mut buf = Vec::new();
225 let mut chunk = [0u8; 1024];
226 loop {
227 let n = sock.read(&mut chunk).await.unwrap_or(0);
228 if n == 0 {
229 return;
230 }
231 buf.extend_from_slice(&chunk[..n]);
232 if buf.windows(4).any(|w| w == b"\r\n\r\n") {
233 return;
234 }
235 }
236}
237
238async fn mock_url(sse_body: &str) -> String {
239 let owned = format!(
240 "HTTP/1.1 200 OK\r\ncontent-type: text/event-stream\r\nconnection: close\r\n\r\n{sse_body}"
241 );
242 spawn_server(owned.into_bytes()).await
243}
244
245async fn error_url(status: u16, json: &str) -> String {
246 let owned = format!(
247 "HTTP/1.1 {status} Err\r\ncontent-type: application/json\r\nconnection: close\r\n\r\n{json}"
248 );
249 spawn_server(owned.into_bytes()).await
250}
251
252#[test]
253fn body_sanitizes_unsupported_schema_keywords_for_gemini() {
254 let mut req = ChatRequest::new("gemini-2.5-flash");
255 req.messages = vec![Message::user_text("test")];
256 req.tools = vec![ToolDefinition::new(
257 "complex_tool",
258 "A tool with schema keywords unsupported by Gemini",
259 serde_json::json!({
260 "$schema": "http://json-schema.org/draft-07/schema#",
261 "type": "object",
262 "additionalProperties": false,
263 "properties": {
264 "name": {
265 "type": "string",
266 "description": "The name"
267 },
268 "nested": {
269 "type": "object",
270 "additionalProperties": false,
271 "properties": {
272 "inner": {"type": "string"}
273 }
274 }
275 },
276 "patternProperties": {
277 "^x-": {"type": "string"}
278 },
279 "definitions": {
280 "something": {}
281 }
282 }),
283 )];
284
285 let body = build_body(&req).unwrap();
286 let params = &body["tools"][0]["functionDeclarations"][0]["parameters"];
287 assert!(params.get("$schema").is_none());
288 assert!(params.get("additionalProperties").is_none());
289 assert!(params.get("patternProperties").is_none());
290 assert!(params.get("definitions").is_none());
291 assert!(
292 params["properties"]["nested"]
293 .get("additionalProperties")
294 .is_none()
295 );
296 assert_eq!(params["properties"]["name"]["type"], "string");
297}
298
299#[test]
300fn body_serializes_thought_signature_on_assistant_function_calls() {
301 let mut req = ChatRequest::new("gemini-3.8-flash");
302 req.messages = vec![
303 Message::user_text("what is the weather?"),
304 Message::assistant(vec![
305 ContentBlock::Thinking {
306 text: String::new(),
307 signature: Some("sig_abc_123".into()),
308 },
309 ContentBlock::ToolUse {
310 id: "call_1".into(),
311 name: "get_weather".into(),
312 input: serde_json::json!({"location": "Tokyo"}),
313 },
314 ]),
315 Message {
316 role: Role::User,
317 content: vec![ContentBlock::tool_result("call_1", "Sunny 22C")],
318 },
319 ];
320
321 let body = build_body(&req).unwrap();
322 let contents = body["contents"].as_array().unwrap();
323 assert_eq!(contents.len(), 3);
324 let model_parts = contents[1]["parts"].as_array().unwrap();
325 assert_eq!(model_parts.len(), 1);
326 assert_eq!(model_parts[0]["functionCall"]["name"], "get_weather");
327 assert_eq!(model_parts[0]["thoughtSignature"], "sig_abc_123");
328}
329

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