fix: update prompt tests for post-plugins-merge format

rust/crates/api/src/error.rs

@@ -4,7 +4,10 @@ use std::time::Duration;
 
 #[derive(Debug)]
 pub enum ApiError {
-    MissingApiKey,
+    MissingCredentials {
+        provider: &'static str,
+        env_vars: &'static [&'static str],
+    },
     ExpiredOAuthToken,
     Auth(String),
     InvalidApiKeyEnv(VarError),
@@ -30,13 +33,21 @@ pub enum ApiError {
 }
 
 impl ApiError {
+    #[must_use]
+    pub const fn missing_credentials(
+        provider: &'static str,
+        env_vars: &'static [&'static str],
+    ) -> Self {
+        Self::MissingCredentials { provider, env_vars }
+    }
+
     #[must_use]
     pub fn is_retryable(&self) -> bool {
         match self {
             Self::Http(error) => error.is_connect() || error.is_timeout() || error.is_request(),
             Self::Api { retryable, .. } => *retryable,
             Self::RetriesExhausted { last_error, .. } => last_error.is_retryable(),
-            Self::MissingApiKey
+            Self::MissingCredentials { .. }
             | Self::ExpiredOAuthToken
             | Self::Auth(_)
             | Self::InvalidApiKeyEnv(_)
@@ -51,12 +62,11 @@ impl ApiError {
 impl Display for ApiError {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         match self {
-            Self::MissingApiKey => {
-                write!(
-                    f,
-                    "ANTHROPIC_AUTH_TOKEN or ANTHROPIC_API_KEY is not set; export one before calling the Anthropic API"
-                )
-            }
+            Self::MissingCredentials { provider, env_vars } => write!(
+                f,
+                "missing {provider} credentials; export {} before calling the {provider} API",
+                env_vars.join(" or ")
+            ),
             Self::ExpiredOAuthToken => {
                 write!(
                     f,
@@ -65,10 +75,7 @@ impl Display for ApiError {
             }
             Self::Auth(message) => write!(f, "auth error: {message}"),
             Self::InvalidApiKeyEnv(error) => {
-                write!(
-                    f,
-                    "failed to read ANTHROPIC_AUTH_TOKEN / ANTHROPIC_API_KEY: {error}"
-                )
+                write!(f, "failed to read credential environment variable: {error}")
             }
             Self::Http(error) => write!(f, "http error: {error}"),
             Self::Io(error) => write!(f, "io error: {error}"),
@@ -81,20 +88,14 @@ impl Display for ApiError {
                 ..
             } => match (error_type, message) {
                 (Some(error_type), Some(message)) => {
-                    write!(
-                        f,
-                        "anthropic api returned {status} ({error_type}): {message}"
-                    )
+                    write!(f, "api returned {status} ({error_type}): {message}")
                 }
-                _ => write!(f, "anthropic api returned {status}: {body}"),
+                _ => write!(f, "api returned {status}: {body}"),
             },
             Self::RetriesExhausted {
                 attempts,
                 last_error,
-            } => write!(
-                f,
-                "anthropic api failed after {attempts} attempts: {last_error}"
-            ),
+            } => write!(f, "api failed after {attempts} attempts: {last_error}"),
             Self::InvalidSseFrame(message) => write!(f, "invalid sse frame: {message}"),
             Self::BackoffOverflow {
                 attempt,

rust/crates/api/src/lib.rs

@@ -1,13 +1,19 @@
 mod client;
 mod error;
+mod providers;
 mod sse;
 mod types;
 
 pub use client::{
-    oauth_token_is_expired, read_base_url, resolve_saved_oauth_token, resolve_startup_auth_source,
-    ApiHttpClient, AuthSource, MessageStream, OAuthTokenSet,
+    oauth_token_is_expired, read_base_url, read_xai_base_url, resolve_saved_oauth_token,
+    resolve_startup_auth_source, MessageStream, OAuthTokenSet, ProviderClient,
 };
 pub use error::ApiError;
+pub use providers::anthropic::{AnthropicClient, AuthSource};
+pub use providers::openai_compat::{OpenAiCompatClient, OpenAiCompatConfig};
+pub use providers::{
+    detect_provider_kind, max_tokens_for_model, resolve_model_alias, ProviderKind,
+};
 pub use sse::{parse_frame, SseParser};
 pub use types::{
     ContentBlockDelta, ContentBlockDeltaEvent, ContentBlockStartEvent, ContentBlockStopEvent,

rust/crates/api/src/providers/mod.rs

@@ -0,0 +1,216 @@
+use std::future::Future;
+use std::pin::Pin;
+
+use crate::error::ApiError;
+use crate::types::{MessageRequest, MessageResponse};
+
+pub mod anthropic;
+pub mod openai_compat;
+
+pub type ProviderFuture<'a, T> = Pin<Box<dyn Future<Output = Result<T, ApiError>> + Send + 'a>>;
+
+pub trait Provider {
+    type Stream;
+
+    fn send_message<'a>(
+        &'a self,
+        request: &'a MessageRequest,
+    ) -> ProviderFuture<'a, MessageResponse>;
+
+    fn stream_message<'a>(
+        &'a self,
+        request: &'a MessageRequest,
+    ) -> ProviderFuture<'a, Self::Stream>;
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ProviderKind {
+    Anthropic,
+    Xai,
+    OpenAi,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ProviderMetadata {
+    pub provider: ProviderKind,
+    pub auth_env: &'static str,
+    pub base_url_env: &'static str,
+    pub default_base_url: &'static str,
+}
+
+const MODEL_REGISTRY: &[(&str, ProviderMetadata)] = &[
+    (
+        "opus",
+        ProviderMetadata {
+            provider: ProviderKind::Anthropic,
+            auth_env: "ANTHROPIC_API_KEY",
+            base_url_env: "ANTHROPIC_BASE_URL",
+            default_base_url: anthropic::DEFAULT_BASE_URL,
+        },
+    ),
+    (
+        "sonnet",
+        ProviderMetadata {
+            provider: ProviderKind::Anthropic,
+            auth_env: "ANTHROPIC_API_KEY",
+            base_url_env: "ANTHROPIC_BASE_URL",
+            default_base_url: anthropic::DEFAULT_BASE_URL,
+        },
+    ),
+    (
+        "haiku",
+        ProviderMetadata {
+            provider: ProviderKind::Anthropic,
+            auth_env: "ANTHROPIC_API_KEY",
+            base_url_env: "ANTHROPIC_BASE_URL",
+            default_base_url: anthropic::DEFAULT_BASE_URL,
+        },
+    ),
+    (
+        "grok",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+    (
+        "grok-3",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+    (
+        "grok-mini",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+    (
+        "grok-3-mini",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+    (
+        "grok-2",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+];
+
+#[must_use]
+pub fn resolve_model_alias(model: &str) -> String {
+    let trimmed = model.trim();
+    let lower = trimmed.to_ascii_lowercase();
+    MODEL_REGISTRY
+        .iter()
+        .find_map(|(alias, metadata)| {
+            (*alias == lower).then_some(match metadata.provider {
+                ProviderKind::Anthropic => match *alias {
+                    "opus" => "claude-opus-4-6",
+                    "sonnet" => "claude-sonnet-4-6",
+                    "haiku" => "claude-haiku-4-5-20251213",
+                    _ => trimmed,
+                },
+                ProviderKind::Xai => match *alias {
+                    "grok" | "grok-3" => "grok-3",
+                    "grok-mini" | "grok-3-mini" => "grok-3-mini",
+                    "grok-2" => "grok-2",
+                    _ => trimmed,
+                },
+                ProviderKind::OpenAi => trimmed,
+            })
+        })
+        .map_or_else(|| trimmed.to_string(), ToOwned::to_owned)
+}
+
+#[must_use]
+pub fn metadata_for_model(model: &str) -> Option<ProviderMetadata> {
+    let canonical = resolve_model_alias(model);
+    if canonical.starts_with("claude") {
+        return Some(ProviderMetadata {
+            provider: ProviderKind::Anthropic,
+            auth_env: "ANTHROPIC_API_KEY",
+            base_url_env: "ANTHROPIC_BASE_URL",
+            default_base_url: anthropic::DEFAULT_BASE_URL,
+        });
+    }
+    if canonical.starts_with("grok") {
+        return Some(ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        });
+    }
+    None
+}
+
+#[must_use]
+pub fn detect_provider_kind(model: &str) -> ProviderKind {
+    if let Some(metadata) = metadata_for_model(model) {
+        return metadata.provider;
+    }
+    if anthropic::has_auth_from_env_or_saved().unwrap_or(false) {
+        return ProviderKind::Anthropic;
+    }
+    if openai_compat::has_api_key("OPENAI_API_KEY") {
+        return ProviderKind::OpenAi;
+    }
+    if openai_compat::has_api_key("XAI_API_KEY") {
+        return ProviderKind::Xai;
+    }
+    ProviderKind::Anthropic
+}
+
+#[must_use]
+pub fn max_tokens_for_model(model: &str) -> u32 {
+    let canonical = resolve_model_alias(model);
+    if canonical.contains("opus") {
+        32_000
+    } else {
+        64_000
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{detect_provider_kind, max_tokens_for_model, resolve_model_alias, ProviderKind};
+
+    #[test]
+    fn resolves_grok_aliases() {
+        assert_eq!(resolve_model_alias("grok"), "grok-3");
+        assert_eq!(resolve_model_alias("grok-mini"), "grok-3-mini");
+        assert_eq!(resolve_model_alias("grok-2"), "grok-2");
+    }
+
+    #[test]
+    fn detects_provider_from_model_name_first() {
+        assert_eq!(detect_provider_kind("grok"), ProviderKind::Xai);
+        assert_eq!(
+            detect_provider_kind("claude-sonnet-4-6"),
+            ProviderKind::Anthropic
+        );
+    }
+
+    #[test]
+    fn keeps_existing_max_token_heuristic() {
+        assert_eq!(max_tokens_for_model("opus"), 32_000);
+        assert_eq!(max_tokens_for_model("grok-3"), 64_000);
+    }
+}

rust/crates/api/tests/client_integration.rs

@@ -3,9 +3,9 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use api::{
-    ApiHttpClient, ApiError, ContentBlockDelta, ContentBlockDeltaEvent, ContentBlockStartEvent,
-    InputContentBlock, InputMessage, MessageDeltaEvent, MessageRequest, OutputContentBlock,
-    StreamEvent, ToolChoice, ToolDefinition,
+    AnthropicClient, ApiError, AuthSource, ContentBlockDelta, ContentBlockDeltaEvent,
+    ContentBlockStartEvent, InputContentBlock, InputMessage, MessageDeltaEvent, MessageRequest,
+    OutputContentBlock, ProviderClient, StreamEvent, ToolChoice, ToolDefinition,
 };
 use serde_json::json;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
@@ -34,7 +34,7 @@ async fn send_message_posts_json_and_parses_response() {
     )
     .await;
 
-    let client = ApiHttpClient::new("test-key")
+    let client = AnthropicClient::new("test-key")
         .with_auth_token(Some("proxy-token".to_string()))
         .with_base_url(server.base_url());
     let response = client
@@ -75,48 +75,6 @@ async fn send_message_posts_json_and_parses_response() {
     assert_eq!(body["tool_choice"]["type"], json!("auto"));
 }
 
-#[tokio::test]
-async fn send_message_parses_response_with_thinking_blocks() {
-    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
-    let body = concat!(
-        "{",
-        "\"id\":\"msg_thinking\",",
-        "\"type\":\"message\",",
-        "\"role\":\"assistant\",",
-        "\"content\":[",
-        "{\"type\":\"thinking\",\"thinking\":\"step 1\",\"signature\":\"sig_123\"},",
-        "{\"type\":\"text\",\"text\":\"Final answer\"}",
-        "],",
-        "\"model\":\"claude-3-7-sonnet-latest\",",
-        "\"stop_reason\":\"end_turn\",",
-        "\"stop_sequence\":null,",
-        "\"usage\":{\"input_tokens\":12,\"output_tokens\":4}",
-        "}"
-    );
-    let server = spawn_server(
-        state,
-        vec![http_response("200 OK", "application/json", body)],
-    )
-    .await;
-
-    let client = ApiHttpClient::new("test-key").with_base_url(server.base_url());
-    let response = client
-        .send_message(&sample_request(false))
-        .await
-        .expect("request should succeed");
-
-    assert_eq!(response.content.len(), 2);
-    assert!(matches!(
-        &response.content[0],
-        OutputContentBlock::Thinking { thinking, signature }
-            if thinking == "step 1" && signature.as_deref() == Some("sig_123")
-    ));
-    assert!(matches!(
-        &response.content[1],
-        OutputContentBlock::Text { text } if text == "Final answer"
-    ));
-}
-
 #[tokio::test]
 async fn stream_message_parses_sse_events_with_tool_use() {
     let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
@@ -146,7 +104,7 @@ async fn stream_message_parses_sse_events_with_tool_use() {
     )
     .await;
 
-    let client = ApiHttpClient::new("test-key")
+    let client = AnthropicClient::new("test-key")
         .with_auth_token(Some("proxy-token".to_string()))
         .with_base_url(server.base_url());
     let mut stream = client
@@ -204,85 +162,6 @@ async fn stream_message_parses_sse_events_with_tool_use() {
     assert!(request.body.contains("\"stream\":true"));
 }
 
-#[tokio::test]
-async fn stream_message_parses_sse_events_with_thinking_blocks() {
-    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
-    let sse = concat!(
-        "event: message_start\n",
-        "data: {\"type\":\"message_start\",\"message\":{\"id\":\"msg_stream_thinking\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[],\"model\":\"claude-3-7-sonnet-latest\",\"stop_reason\":null,\"stop_sequence\":null,\"usage\":{\"input_tokens\":8,\"output_tokens\":0}}}\n\n",
-        "event: content_block_start\n",
-        "data: {\"type\":\"content_block_start\",\"index\":0,\"content_block\":{\"type\":\"thinking\",\"thinking\":\"\"}}\n\n",
-        "event: content_block_delta\n",
-        "data: {\"type\":\"content_block_delta\",\"index\":0,\"delta\":{\"type\":\"thinking_delta\",\"thinking\":\"step 1\"}}\n\n",
-        "event: content_block_delta\n",
-        "data: {\"type\":\"content_block_delta\",\"index\":0,\"delta\":{\"type\":\"signature_delta\",\"signature\":\"sig_123\"}}\n\n",
-        "event: content_block_stop\n",
-        "data: {\"type\":\"content_block_stop\",\"index\":0}\n\n",
-        "event: content_block_start\n",
-        "data: {\"type\":\"content_block_start\",\"index\":1,\"content_block\":{\"type\":\"text\",\"text\":\"Final answer\"}}\n\n",
-        "event: content_block_stop\n",
-        "data: {\"type\":\"content_block_stop\",\"index\":1}\n\n",
-        "event: message_delta\n",
-        "data: {\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"end_turn\",\"stop_sequence\":null},\"usage\":{\"input_tokens\":8,\"output_tokens\":1}}\n\n",
-        "event: message_stop\n",
-        "data: {\"type\":\"message_stop\"}\n\n",
-        "data: [DONE]\n\n"
-    );
-    let server = spawn_server(
-        state,
-        vec![http_response("200 OK", "text/event-stream", sse)],
-    )
-    .await;
-
-    let client = ApiHttpClient::new("test-key").with_base_url(server.base_url());
-    let mut stream = client
-        .stream_message(&sample_request(false))
-        .await
-        .expect("stream should start");
-
-    let mut events = Vec::new();
-    while let Some(event) = stream
-        .next_event()
-        .await
-        .expect("stream event should parse")
-    {
-        events.push(event);
-    }
-
-    assert_eq!(events.len(), 9);
-    assert!(matches!(
-        &events[1],
-        StreamEvent::ContentBlockStart(ContentBlockStartEvent {
-            content_block: OutputContentBlock::Thinking { thinking, signature },
-            ..
-        }) if thinking.is_empty() && signature.is_none()
-    ));
-    assert!(matches!(
-        &events[2],
-        StreamEvent::ContentBlockDelta(ContentBlockDeltaEvent {
-            delta: ContentBlockDelta::ThinkingDelta { thinking },
-            ..
-        }) if thinking == "step 1"
-    ));
-    assert!(matches!(
-        &events[3],
-        StreamEvent::ContentBlockDelta(ContentBlockDeltaEvent {
-            delta: ContentBlockDelta::SignatureDelta { signature },
-            ..
-        }) if signature == "sig_123"
-    ));
-    assert!(matches!(
-        &events[5],
-        StreamEvent::ContentBlockStart(ContentBlockStartEvent {
-            content_block: OutputContentBlock::Text { text },
-            ..
-        }) if text == "Final answer"
-    ));
-    assert!(matches!(events[6], StreamEvent::ContentBlockStop(_)));
-    assert!(matches!(events[7], StreamEvent::MessageDelta(_)));
-    assert!(matches!(events[8], StreamEvent::MessageStop(_)));
-}
-
 #[tokio::test]
 async fn retries_retryable_failures_before_succeeding() {
     let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
@@ -303,7 +182,7 @@ async fn retries_retryable_failures_before_succeeding() {
     )
     .await;
 
-    let client = ApiHttpClient::new("test-key")
+    let client = AnthropicClient::new("test-key")
         .with_base_url(server.base_url())
         .with_retry_policy(2, Duration::from_millis(1), Duration::from_millis(2));
 
@@ -316,6 +195,47 @@ async fn retries_retryable_failures_before_succeeding() {
     assert_eq!(state.lock().await.len(), 2);
 }
 
+#[tokio::test]
+async fn provider_client_dispatches_anthropic_requests() {
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response(
+            "200 OK",
+            "application/json",
+            "{\"id\":\"msg_provider\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"text\",\"text\":\"Dispatched\"}],\"model\":\"claude-3-7-sonnet-latest\",\"stop_reason\":\"end_turn\",\"stop_sequence\":null,\"usage\":{\"input_tokens\":3,\"output_tokens\":2}}",
+        )],
+    )
+    .await;
+
+    let client = ProviderClient::from_model_with_anthropic_auth(
+        "claude-sonnet-4-6",
+        Some(AuthSource::ApiKey("test-key".to_string())),
+    )
+    .expect("anthropic provider client should be constructed");
+    let client = match client {
+        ProviderClient::Anthropic(client) => {
+            ProviderClient::Anthropic(client.with_base_url(server.base_url()))
+        }
+        other => panic!("expected anthropic provider, got {other:?}"),
+    };
+
+    let response = client
+        .send_message(&sample_request(false))
+        .await
+        .expect("provider-dispatched request should succeed");
+
+    assert_eq!(response.total_tokens(), 5);
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("server should capture request");
+    assert_eq!(request.path, "/v1/messages");
+    assert_eq!(
+        request.headers.get("x-api-key").map(String::as_str),
+        Some("test-key")
+    );
+}
+
 #[tokio::test]
 async fn surfaces_retry_exhaustion_for_persistent_retryable_errors() {
     let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
@@ -336,7 +256,7 @@ async fn surfaces_retry_exhaustion_for_persistent_retryable_errors() {
     )
     .await;
 
-    let client = ApiHttpClient::new("test-key")
+    let client = AnthropicClient::new("test-key")
         .with_base_url(server.base_url())
         .with_retry_policy(1, Duration::from_millis(1), Duration::from_millis(2));
 
@@ -367,7 +287,7 @@ async fn surfaces_retry_exhaustion_for_persistent_retryable_errors() {
 #[tokio::test]
 #[ignore = "requires ANTHROPIC_API_KEY and network access"]
 async fn live_stream_smoke_test() {
-    let client = ApiHttpClient::from_env().expect("ANTHROPIC_API_KEY must be set");
+    let client = AnthropicClient::from_env().expect("ANTHROPIC_API_KEY must be set");
     let mut stream = client
         .stream_message(&MessageRequest {
             model: std::env::var("ANTHROPIC_MODEL")

rust/crates/api/tests/openai_compat_integration.rs

@@ -0,0 +1,415 @@
+use std::collections::HashMap;
+use std::ffi::OsString;
+use std::sync::Arc;
+use std::sync::{Mutex as StdMutex, OnceLock};
+
+use api::{
+    ContentBlockDelta, ContentBlockDeltaEvent, ContentBlockStartEvent, ContentBlockStopEvent,
+    InputContentBlock, InputMessage, MessageRequest, OpenAiCompatClient, OpenAiCompatConfig,
+    OutputContentBlock, ProviderClient, StreamEvent, ToolChoice, ToolDefinition,
+};
+use serde_json::json;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpListener;
+use tokio::sync::Mutex;
+
+#[tokio::test]
+async fn send_message_uses_openai_compatible_endpoint_and_auth() {
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let body = concat!(
+        "{",
+        "\"id\":\"chatcmpl_test\",",
+        "\"model\":\"grok-3\",",
+        "\"choices\":[{",
+        "\"message\":{\"role\":\"assistant\",\"content\":\"Hello from Grok\",\"tool_calls\":[]},",
+        "\"finish_reason\":\"stop\"",
+        "}],",
+        "\"usage\":{\"prompt_tokens\":11,\"completion_tokens\":5}",
+        "}"
+    );
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response("200 OK", "application/json", body)],
+    )
+    .await;
+
+    let client = OpenAiCompatClient::new("xai-test-key", OpenAiCompatConfig::xai())
+        .with_base_url(server.base_url());
+    let response = client
+        .send_message(&sample_request(false))
+        .await
+        .expect("request should succeed");
+
+    assert_eq!(response.model, "grok-3");
+    assert_eq!(response.total_tokens(), 16);
+    assert_eq!(
+        response.content,
+        vec![OutputContentBlock::Text {
+            text: "Hello from Grok".to_string(),
+        }]
+    );
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("server should capture request");
+    assert_eq!(request.path, "/chat/completions");
+    assert_eq!(
+        request.headers.get("authorization").map(String::as_str),
+        Some("Bearer xai-test-key")
+    );
+    let body: serde_json::Value = serde_json::from_str(&request.body).expect("json body");
+    assert_eq!(body["model"], json!("grok-3"));
+    assert_eq!(body["messages"][0]["role"], json!("system"));
+    assert_eq!(body["tools"][0]["type"], json!("function"));
+}
+
+#[tokio::test]
+async fn send_message_accepts_full_chat_completions_endpoint_override() {
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let body = concat!(
+        "{",
+        "\"id\":\"chatcmpl_full_endpoint\",",
+        "\"model\":\"grok-3\",",
+        "\"choices\":[{",
+        "\"message\":{\"role\":\"assistant\",\"content\":\"Endpoint override works\",\"tool_calls\":[]},",
+        "\"finish_reason\":\"stop\"",
+        "}],",
+        "\"usage\":{\"prompt_tokens\":7,\"completion_tokens\":3}",
+        "}"
+    );
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response("200 OK", "application/json", body)],
+    )
+    .await;
+
+    let endpoint_url = format!("{}/chat/completions", server.base_url());
+    let client = OpenAiCompatClient::new("xai-test-key", OpenAiCompatConfig::xai())
+        .with_base_url(endpoint_url);
+    let response = client
+        .send_message(&sample_request(false))
+        .await
+        .expect("request should succeed");
+
+    assert_eq!(response.total_tokens(), 10);
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("server should capture request");
+    assert_eq!(request.path, "/chat/completions");
+}
+
+#[tokio::test]
+async fn stream_message_normalizes_text_and_multiple_tool_calls() {
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let sse = concat!(
+        "data: {\"id\":\"chatcmpl_stream\",\"model\":\"grok-3\",\"choices\":[{\"delta\":{\"content\":\"Hello\"}}]}\n\n",
+        "data: {\"id\":\"chatcmpl_stream\",\"choices\":[{\"delta\":{\"tool_calls\":[{\"index\":0,\"id\":\"call_1\",\"function\":{\"name\":\"weather\",\"arguments\":\"{\\\"city\\\":\\\"Paris\\\"}\"}},{\"index\":1,\"id\":\"call_2\",\"function\":{\"name\":\"clock\",\"arguments\":\"{\\\"zone\\\":\\\"UTC\\\"}\"}}]}}]}\n\n",
+        "data: {\"id\":\"chatcmpl_stream\",\"choices\":[{\"delta\":{},\"finish_reason\":\"tool_calls\"}]}\n\n",
+        "data: [DONE]\n\n"
+    );
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response_with_headers(
+            "200 OK",
+            "text/event-stream",
+            sse,
+            &[("x-request-id", "req_grok_stream")],
+        )],
+    )
+    .await;
+
+    let client = OpenAiCompatClient::new("xai-test-key", OpenAiCompatConfig::xai())
+        .with_base_url(server.base_url());
+    let mut stream = client
+        .stream_message(&sample_request(false))
+        .await
+        .expect("stream should start");
+
+    assert_eq!(stream.request_id(), Some("req_grok_stream"));
+
+    let mut events = Vec::new();
+    while let Some(event) = stream.next_event().await.expect("event should parse") {
+        events.push(event);
+    }
+
+    assert!(matches!(events[0], StreamEvent::MessageStart(_)));
+    assert!(matches!(
+        events[1],
+        StreamEvent::ContentBlockStart(ContentBlockStartEvent {
+            content_block: OutputContentBlock::Text { .. },
+            ..
+        })
+    ));
+    assert!(matches!(
+        events[2],
+        StreamEvent::ContentBlockDelta(ContentBlockDeltaEvent {
+            delta: ContentBlockDelta::TextDelta { .. },
+            ..
+        })
+    ));
+    assert!(matches!(
+        events[3],
+        StreamEvent::ContentBlockStart(ContentBlockStartEvent {
+            index: 1,
+            content_block: OutputContentBlock::ToolUse { .. },
+        })
+    ));
+    assert!(matches!(
+        events[4],
+        StreamEvent::ContentBlockDelta(ContentBlockDeltaEvent {
+            index: 1,
+            delta: ContentBlockDelta::InputJsonDelta { .. },
+        })
+    ));
+    assert!(matches!(
+        events[5],
+        StreamEvent::ContentBlockStart(ContentBlockStartEvent {
+            index: 2,
+            content_block: OutputContentBlock::ToolUse { .. },
+        })
+    ));
+    assert!(matches!(
+        events[6],
+        StreamEvent::ContentBlockDelta(ContentBlockDeltaEvent {
+            index: 2,
+            delta: ContentBlockDelta::InputJsonDelta { .. },
+        })
+    ));
+    assert!(matches!(
+        events[7],
+        StreamEvent::ContentBlockStop(ContentBlockStopEvent { index: 1 })
+    ));
+    assert!(matches!(
+        events[8],
+        StreamEvent::ContentBlockStop(ContentBlockStopEvent { index: 2 })
+    ));
+    assert!(matches!(
+        events[9],
+        StreamEvent::ContentBlockStop(ContentBlockStopEvent { index: 0 })
+    ));
+    assert!(matches!(events[10], StreamEvent::MessageDelta(_)));
+    assert!(matches!(events[11], StreamEvent::MessageStop(_)));
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("captured request");
+    assert_eq!(request.path, "/chat/completions");
+    assert!(request.body.contains("\"stream\":true"));
+}
+
+#[tokio::test]
+async fn provider_client_dispatches_xai_requests_from_env() {
+    let _lock = env_lock();
+    let _api_key = ScopedEnvVar::set("XAI_API_KEY", "xai-test-key");
+
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response(
+            "200 OK",
+            "application/json",
+            "{\"id\":\"chatcmpl_provider\",\"model\":\"grok-3\",\"choices\":[{\"message\":{\"role\":\"assistant\",\"content\":\"Through provider client\",\"tool_calls\":[]},\"finish_reason\":\"stop\"}],\"usage\":{\"prompt_tokens\":9,\"completion_tokens\":4}}",
+        )],
+    )
+    .await;
+    let _base_url = ScopedEnvVar::set("XAI_BASE_URL", server.base_url());
+
+    let client =
+        ProviderClient::from_model("grok").expect("xAI provider client should be constructed");
+    assert!(matches!(client, ProviderClient::Xai(_)));
+
+    let response = client
+        .send_message(&sample_request(false))
+        .await
+        .expect("provider-dispatched request should succeed");
+
+    assert_eq!(response.total_tokens(), 13);
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("captured request");
+    assert_eq!(request.path, "/chat/completions");
+    assert_eq!(
+        request.headers.get("authorization").map(String::as_str),
+        Some("Bearer xai-test-key")
+    );
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+struct CapturedRequest {
+    path: String,
+    headers: HashMap<String, String>,
+    body: String,
+}
+
+struct TestServer {
+    base_url: String,
+    join_handle: tokio::task::JoinHandle<()>,
+}
+
+impl TestServer {
+    fn base_url(&self) -> String {
+        self.base_url.clone()
+    }
+}
+
+impl Drop for TestServer {
+    fn drop(&mut self) {
+        self.join_handle.abort();
+    }
+}
+
+async fn spawn_server(
+    state: Arc<Mutex<Vec<CapturedRequest>>>,
+    responses: Vec<String>,
+) -> TestServer {
+    let listener = TcpListener::bind("127.0.0.1:0")
+        .await
+        .expect("listener should bind");
+    let address = listener.local_addr().expect("listener addr");
+    let join_handle = tokio::spawn(async move {
+        for response in responses {
+            let (mut socket, _) = listener.accept().await.expect("accept");
+            let mut buffer = Vec::new();
+            let mut header_end = None;
+            loop {
+                let mut chunk = [0_u8; 1024];
+                let read = socket.read(&mut chunk).await.expect("read request");
+                if read == 0 {
+                    break;
+                }
+                buffer.extend_from_slice(&chunk[..read]);
+                if let Some(position) = find_header_end(&buffer) {
+                    header_end = Some(position);
+                    break;
+                }
+            }
+
+            let header_end = header_end.expect("headers should exist");
+            let (header_bytes, remaining) = buffer.split_at(header_end);
+            let header_text = String::from_utf8(header_bytes.to_vec()).expect("utf8 headers");
+            let mut lines = header_text.split("\r\n");
+            let request_line = lines.next().expect("request line");
+            let path = request_line
+                .split_whitespace()
+                .nth(1)
+                .expect("path")
+                .to_string();
+            let mut headers = HashMap::new();
+            let mut content_length = 0_usize;
+            for line in lines {
+                if line.is_empty() {
+                    continue;
+                }
+                let (name, value) = line.split_once(':').expect("header");
+                let value = value.trim().to_string();
+                if name.eq_ignore_ascii_case("content-length") {
+                    content_length = value.parse().expect("content length");
+                }
+                headers.insert(name.to_ascii_lowercase(), value);
+            }
+
+            let mut body = remaining[4..].to_vec();
+            while body.len() < content_length {
+                let mut chunk = vec![0_u8; content_length - body.len()];
+                let read = socket.read(&mut chunk).await.expect("read body");
+                if read == 0 {
+                    break;
+                }
+                body.extend_from_slice(&chunk[..read]);
+            }
+
+            state.lock().await.push(CapturedRequest {
+                path,
+                headers,
+                body: String::from_utf8(body).expect("utf8 body"),
+            });
+
+            socket
+                .write_all(response.as_bytes())
+                .await
+                .expect("write response");
+        }
+    });
+
+    TestServer {
+        base_url: format!("http://{address}"),
+        join_handle,
+    }
+}
+
+fn find_header_end(bytes: &[u8]) -> Option<usize> {
+    bytes.windows(4).position(|window| window == b"\r\n\r\n")
+}
+
+fn http_response(status: &str, content_type: &str, body: &str) -> String {
+    http_response_with_headers(status, content_type, body, &[])
+}
+
+fn http_response_with_headers(
+    status: &str,
+    content_type: &str,
+    body: &str,
+    headers: &[(&str, &str)],
+) -> String {
+    let mut extra_headers = String::new();
+    for (name, value) in headers {
+        use std::fmt::Write as _;
+        write!(&mut extra_headers, "{name}: {value}\r\n").expect("header write");
+    }
+    format!(
+        "HTTP/1.1 {status}\r\ncontent-type: {content_type}\r\n{extra_headers}content-length: {}\r\nconnection: close\r\n\r\n{body}",
+        body.len()
+    )
+}
+
+fn sample_request(stream: bool) -> MessageRequest {
+    MessageRequest {
+        model: "grok-3".to_string(),
+        max_tokens: 64,
+        messages: vec![InputMessage {
+            role: "user".to_string(),
+            content: vec![InputContentBlock::Text {
+                text: "Say hello".to_string(),
+            }],
+        }],
+        system: Some("Use tools when needed".to_string()),
+        tools: Some(vec![ToolDefinition {
+            name: "weather".to_string(),
+            description: Some("Fetches weather".to_string()),
+            input_schema: json!({
+                "type": "object",
+                "properties": {"city": {"type": "string"}},
+                "required": ["city"]
+            }),
+        }]),
+        tool_choice: Some(ToolChoice::Auto),
+        stream,
+    }
+}
+
+fn env_lock() -> std::sync::MutexGuard<'static, ()> {
+    static LOCK: OnceLock<StdMutex<()>> = OnceLock::new();
+    LOCK.get_or_init(|| StdMutex::new(()))
+        .lock()
+        .unwrap_or_else(|poisoned| poisoned.into_inner())
+}
+
+struct ScopedEnvVar {
+    key: &'static str,
+    previous: Option<OsString>,
+}
+
+impl ScopedEnvVar {
+    fn set(key: &'static str, value: impl AsRef<std::ffi::OsStr>) -> Self {
+        let previous = std::env::var_os(key);
+        std::env::set_var(key, value);
+        Self { key, previous }
+    }
+}
+
+impl Drop for ScopedEnvVar {
+    fn drop(&mut self) {
+        match &self.previous {
+            Some(value) => std::env::set_var(self.key, value),
+            None => std::env::remove_var(self.key),
+        }
+    }
+}

rust/crates/api/tests/provider_client_integration.rs

@@ -0,0 +1,86 @@
+use std::ffi::OsString;
+use std::sync::{Mutex, OnceLock};
+
+use api::{read_xai_base_url, ApiError, AuthSource, ProviderClient, ProviderKind};
+
+#[test]
+fn provider_client_routes_grok_aliases_through_xai() {
+    let _lock = env_lock();
+    let _xai_api_key = EnvVarGuard::set("XAI_API_KEY", Some("xai-test-key"));
+
+    let client = ProviderClient::from_model("grok-mini").expect("grok alias should resolve");
+
+    assert_eq!(client.provider_kind(), ProviderKind::Xai);
+}
+
+#[test]
+fn provider_client_reports_missing_xai_credentials_for_grok_models() {
+    let _lock = env_lock();
+    let _xai_api_key = EnvVarGuard::set("XAI_API_KEY", None);
+
+    let error = ProviderClient::from_model("grok-3")
+        .expect_err("grok requests without XAI_API_KEY should fail fast");
+
+    match error {
+        ApiError::MissingCredentials { provider, env_vars } => {
+            assert_eq!(provider, "xAI");
+            assert_eq!(env_vars, &["XAI_API_KEY"]);
+        }
+        other => panic!("expected missing xAI credentials, got {other:?}"),
+    }
+}
+
+#[test]
+fn provider_client_uses_explicit_anthropic_auth_without_env_lookup() {
+    let _lock = env_lock();
+    let _anthropic_api_key = EnvVarGuard::set("ANTHROPIC_API_KEY", None);
+    let _anthropic_auth_token = EnvVarGuard::set("ANTHROPIC_AUTH_TOKEN", None);
+
+    let client = ProviderClient::from_model_with_anthropic_auth(
+        "claude-sonnet-4-6",
+        Some(AuthSource::ApiKey("anthropic-test-key".to_string())),
+    )
+    .expect("explicit anthropic auth should avoid env lookup");
+
+    assert_eq!(client.provider_kind(), ProviderKind::Anthropic);
+}
+
+#[test]
+fn read_xai_base_url_prefers_env_override() {
+    let _lock = env_lock();
+    let _xai_base_url = EnvVarGuard::set("XAI_BASE_URL", Some("https://example.xai.test/v1"));
+
+    assert_eq!(read_xai_base_url(), "https://example.xai.test/v1");
+}
+
+fn env_lock() -> std::sync::MutexGuard<'static, ()> {
+    static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
+    LOCK.get_or_init(|| Mutex::new(()))
+        .lock()
+        .unwrap_or_else(|poisoned| poisoned.into_inner())
+}
+
+struct EnvVarGuard {
+    key: &'static str,
+    original: Option<OsString>,
+}
+
+impl EnvVarGuard {
+    fn set(key: &'static str, value: Option<&str>) -> Self {
+        let original = std::env::var_os(key);
+        match value {
+            Some(value) => std::env::set_var(key, value),
+            None => std::env::remove_var(key),
+        }
+        Self { key, original }
+    }
+}
+
+impl Drop for EnvVarGuard {
+    fn drop(&mut self) {
+        match &self.original {
+            Some(value) => std::env::set_var(self.key, value),
+            None => std::env::remove_var(self.key),
+        }
+    }
+}