Add support for OpenRouter as a language model provider (#29496)

This pull request adds full integration with OpenRouter, allowing users
to access a wide variety of language models through a single API key.

**Implementation Details:**

* **Provider Registration:** Registers OpenRouter as a new language
model provider within the application's model registry. This includes UI
for API key authentication, token counting, streaming completions, and
tool-call handling.
* **Dedicated Crate:** Adds a new `open_router` crate to manage
interactions with the OpenRouter HTTP API, including model discovery and
streaming helpers.
* **UI & Configuration:** Extends workspace manifests, the settings
schema, icons, and default configurations to surface the OpenRouter
provider and its settings within the UI.
* **Readability:** Reformats JSON arrays within the settings files for
improved readability.

**Design Decisions & Discussion Points:**

* **Code Reuse:** I leveraged much of the existing logic from the
`openai` provider integration due to the significant similarities
between the OpenAI and OpenRouter API specifications.
* **Default Model:** I set the default model to `openrouter/auto`. This
model automatically routes user prompts to the most suitable underlying
model on OpenRouter, providing a convenient starting point.
* **Model Population Strategy:**
* <strike>I've implemented dynamic population of available models by
querying the OpenRouter API upon initialization.
* Currently, this involves three separate API calls: one for all models,
one for tool-use models, and one for models good at programming.
* The data from the tool-use API call sets a `tool_use` flag for
relevant models.
* The data from the programming models API call is used to sort the
list, prioritizing coding-focused models in the dropdown.</strike>
* <strike>**Feedback Welcome:** I acknowledge this multi-call approach
is API-intensive. I am open to feedback and alternative implementation
suggestions if the team believes this can be optimized.</strike>
    * **Update: Now this has been simplified to one api call.**
* **UI/UX Considerations:**
* <strike>Authentication Method: Currently, I've implemented the
standard API key input in settings, similar to other providers like
OpenAI/Anthropic. However, OpenRouter also supports OAuth 2.0 with PKCE.
This could offer a potentially smoother, more integrated setup
experience for users (e.g., clicking a button to authorize instead of
copy-pasting a key). Should we prioritize implementing OAuth PKCE now,
or perhaps add it as an alternative option later?</strike>(PKCE is not
straight forward and complicated so skipping this for now. So that we
can add the support and work on this later.)
* <strike>To visually distinguish models better suited for programming,
I've considered adding a marker (e.g., `</>` or `🧠`) next to their
names. Thoughts on this proposal?</strike>. (This will require a changes
and discussion across model provider. This doesn't fall under the scope
of current PR).
* OpenRouter offers 300+ models. The current implementation loads all of
them. **Feedback Needed:** Should we refine this list or implement more
sophisticated filtering/categorization for better usability?

**Motivation:**

This integration directly addresses one of the most highly upvoted
feature requests/discussions within the Zed community. Adding OpenRouter
support significantly expands the range of AI models accessible to
users.

I welcome feedback from the Zed team on this implementation and the
design choices made. I am eager to refine this feature and make it
available to users.

ISSUES: https://github.com/zed-industries/zed/discussions/16576

Release Notes:

- Added support for OpenRouter as a language model provider.

---------

Signed-off-by: Umesh Yadav <umesh4257@gmail.com>
Co-authored-by: Marshall Bowers <git@maxdeviant.com>

Cargo.lock

@@ -8864,6 +8864,7 @@ dependencies = [
  "mistral",
  "ollama",
  "open_ai",
+ "open_router",
  "partial-json-fixer",
  "project",
  "proto",
@@ -10708,6 +10709,19 @@ dependencies = [
  "workspace-hack",
 ]
 
+[[package]]
+name = "open_router"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "futures 0.3.31",
+ "http_client",
+ "schemars",
+ "serde",
+ "serde_json",
+ "workspace-hack",
+]
+
 [[package]]
 name = "opener"
 version = "0.7.2"

Cargo.toml

@@ -100,6 +100,7 @@ members = [
     "crates/notifications",
     "crates/ollama",
     "crates/open_ai",
+    "crates/open_router",
     "crates/outline",
     "crates/outline_panel",
     "crates/panel",
@@ -307,6 +308,7 @@ node_runtime = { path = "crates/node_runtime" }
 notifications = { path = "crates/notifications" }
 ollama = { path = "crates/ollama" }
 open_ai = { path = "crates/open_ai" }
+open_router = { path = "crates/open_router", features = ["schemars"] }
 outline = { path = "crates/outline" }
 outline_panel = { path = "crates/outline_panel" }
 panel = { path = "crates/panel" }

assets/icons/ai_open_router.svg

@@ -0,0 +1,8 @@
+<svg width="16" height="16" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg" fill="currentColor" stroke="currentColor">
+  <g clip-path="url(#clip0_205_3)">
+    <path d="M0.094 7.78c0.469 0 2.281 -0.405 3.219 -0.936s0.938 -0.531 2.875 -1.906c2.453 -1.741 4.188 -1.158 7.031 -1.158" stroke-width="2.8125" />
+    <path d="m15.969 3.797 -4.805 2.774V1.023z" />
+    <path d="M0 7.781c0.469 0 2.281 0.405 3.219 0.936s0.938 0.531 2.875 1.906C8.547 12.364 10.281 11.781 13.125 11.781" stroke-width="2.8125" />
+    <path d="m15.875 11.764 -4.805 -2.774v5.548z" />
+  </g>
+</svg>

assets/settings/default.json

@@ -1605,6 +1605,9 @@
       "version": "1",
       "api_url": "https://api.openai.com/v1"
     },
+    "open_router": {
+      "api_url": "https://openrouter.ai/api/v1"
+    },
     "lmstudio": {
       "api_url": "http://localhost:1234/api/v0"
     },

crates/agent_settings/src/agent_settings.rs

@@ -730,6 +730,7 @@ impl JsonSchema for LanguageModelProviderSetting {
                 "zed.dev".into(),
                 "copilot_chat".into(),
                 "deepseek".into(),
+                "openrouter".into(),
                 "mistral".into(),
             ]),
             ..Default::default()

crates/icons/src/icons.rs

@@ -18,6 +18,7 @@ pub enum IconName {
     AiMistral,
     AiOllama,
     AiOpenAi,
+    AiOpenRouter,
     AiZed,
     ArrowCircle,
     ArrowDown,

crates/language_models/Cargo.toml

@@ -39,6 +39,7 @@ menu.workspace = true
 mistral = { workspace = true, features = ["schemars"] }
 ollama = { workspace = true, features = ["schemars"] }
 open_ai = { workspace = true, features = ["schemars"] }
+open_router = { workspace = true, features = ["schemars"] }
 partial-json-fixer.workspace = true
 project.workspace = true
 proto.workspace = true

crates/language_models/src/language_models.rs

@@ -19,6 +19,7 @@ use crate::provider::lmstudio::LmStudioLanguageModelProvider;
 use crate::provider::mistral::MistralLanguageModelProvider;
 use crate::provider::ollama::OllamaLanguageModelProvider;
 use crate::provider::open_ai::OpenAiLanguageModelProvider;
+use crate::provider::open_router::OpenRouterLanguageModelProvider;
 pub use crate::settings::*;
 
 pub fn init(user_store: Entity<UserStore>, client: Arc<Client>, fs: Arc<dyn Fs>, cx: &mut App) {
@@ -72,5 +73,9 @@ fn register_language_model_providers(
         BedrockLanguageModelProvider::new(client.http_client(), cx),
         cx,
     );
+    registry.register_provider(
+        OpenRouterLanguageModelProvider::new(client.http_client(), cx),
+        cx,
+    );
     registry.register_provider(CopilotChatLanguageModelProvider::new(cx), cx);
 }

crates/language_models/src/provider.rs

@@ -8,3 +8,4 @@ pub mod lmstudio;
 pub mod mistral;
 pub mod ollama;
 pub mod open_ai;
+pub mod open_router;

crates/language_models/src/provider/open_router.rs

@@ -0,0 +1,788 @@
+use anyhow::{Context as _, Result, anyhow};
+use collections::HashMap;
+use credentials_provider::CredentialsProvider;
+use editor::{Editor, EditorElement, EditorStyle};
+use futures::{FutureExt, Stream, StreamExt, future::BoxFuture};
+use gpui::{
+    AnyView, App, AsyncApp, Context, Entity, FontStyle, Subscription, Task, TextStyle, WhiteSpace,
+};
+use http_client::HttpClient;
+use language_model::{
+    AuthenticateError, LanguageModel, LanguageModelCompletionError, LanguageModelCompletionEvent,
+    LanguageModelId, LanguageModelName, LanguageModelProvider, LanguageModelProviderId,
+    LanguageModelProviderName, LanguageModelProviderState, LanguageModelRequest,
+    LanguageModelToolChoice, LanguageModelToolResultContent, LanguageModelToolUse, MessageContent,
+    RateLimiter, Role, StopReason,
+};
+use open_router::{Model, ResponseStreamEvent, list_models, stream_completion};
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+use settings::{Settings, SettingsStore};
+use std::pin::Pin;
+use std::str::FromStr as _;
+use std::sync::Arc;
+use theme::ThemeSettings;
+use ui::{Icon, IconName, List, Tooltip, prelude::*};
+use util::ResultExt;
+
+use crate::{AllLanguageModelSettings, ui::InstructionListItem};
+
+const PROVIDER_ID: &str = "openrouter";
+const PROVIDER_NAME: &str = "OpenRouter";
+
+#[derive(Default, Clone, Debug, PartialEq)]
+pub struct OpenRouterSettings {
+    pub api_url: String,
+    pub available_models: Vec<AvailableModel>,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct AvailableModel {
+    pub name: String,
+    pub display_name: Option<String>,
+    pub max_tokens: usize,
+    pub max_output_tokens: Option<u32>,
+    pub max_completion_tokens: Option<u32>,
+}
+
+pub struct OpenRouterLanguageModelProvider {
+    http_client: Arc<dyn HttpClient>,
+    state: gpui::Entity<State>,
+}
+
+pub struct State {
+    api_key: Option<String>,
+    api_key_from_env: bool,
+    http_client: Arc<dyn HttpClient>,
+    available_models: Vec<open_router::Model>,
+    fetch_models_task: Option<Task<Result<()>>>,
+    _subscription: Subscription,
+}
+
+const OPENROUTER_API_KEY_VAR: &str = "OPENROUTER_API_KEY";
+
+impl State {
+    fn is_authenticated(&self) -> bool {
+        self.api_key.is_some()
+    }
+
+    fn reset_api_key(&self, cx: &mut Context<Self>) -> Task<Result<()>> {
+        let credentials_provider = <dyn CredentialsProvider>::global(cx);
+        let api_url = AllLanguageModelSettings::get_global(cx)
+            .open_router
+            .api_url
+            .clone();
+        cx.spawn(async move |this, cx| {
+            credentials_provider
+                .delete_credentials(&api_url, &cx)
+                .await
+                .log_err();
+            this.update(cx, |this, cx| {
+                this.api_key = None;
+                this.api_key_from_env = false;
+                cx.notify();
+            })
+        })
+    }
+
+    fn set_api_key(&mut self, api_key: String, cx: &mut Context<Self>) -> Task<Result<()>> {
+        let credentials_provider = <dyn CredentialsProvider>::global(cx);
+        let api_url = AllLanguageModelSettings::get_global(cx)
+            .open_router
+            .api_url
+            .clone();
+        cx.spawn(async move |this, cx| {
+            credentials_provider
+                .write_credentials(&api_url, "Bearer", api_key.as_bytes(), &cx)
+                .await
+                .log_err();
+            this.update(cx, |this, cx| {
+                this.api_key = Some(api_key);
+                cx.notify();
+            })
+        })
+    }
+
+    fn authenticate(&self, cx: &mut Context<Self>) -> Task<Result<(), AuthenticateError>> {
+        if self.is_authenticated() {
+            return Task::ready(Ok(()));
+        }
+
+        let credentials_provider = <dyn CredentialsProvider>::global(cx);
+        let api_url = AllLanguageModelSettings::get_global(cx)
+            .open_router
+            .api_url
+            .clone();
+        cx.spawn(async move |this, cx| {
+            let (api_key, from_env) = if let Ok(api_key) = std::env::var(OPENROUTER_API_KEY_VAR) {
+                (api_key, true)
+            } else {
+                let (_, api_key) = credentials_provider
+                    .read_credentials(&api_url, &cx)
+                    .await?
+                    .ok_or(AuthenticateError::CredentialsNotFound)?;
+                (
+                    String::from_utf8(api_key)
+                        .context(format!("invalid {} API key", PROVIDER_NAME))?,
+                    false,
+                )
+            };
+            this.update(cx, |this, cx| {
+                this.api_key = Some(api_key);
+                this.api_key_from_env = from_env;
+                cx.notify();
+            })?;
+
+            Ok(())
+        })
+    }
+
+    fn fetch_models(&mut self, cx: &mut Context<Self>) -> Task<Result<()>> {
+        let settings = &AllLanguageModelSettings::get_global(cx).open_router;
+        let http_client = self.http_client.clone();
+        let api_url = settings.api_url.clone();
+
+        cx.spawn(async move |this, cx| {
+            let models = list_models(http_client.as_ref(), &api_url).await?;
+
+            this.update(cx, |this, cx| {
+                this.available_models = models;
+                cx.notify();
+            })
+        })
+    }
+
+    fn restart_fetch_models_task(&mut self, cx: &mut Context<Self>) {
+        let task = self.fetch_models(cx);
+        self.fetch_models_task.replace(task);
+    }
+}
+
+impl OpenRouterLanguageModelProvider {
+    pub fn new(http_client: Arc<dyn HttpClient>, cx: &mut App) -> Self {
+        let state = cx.new(|cx| State {
+            api_key: None,
+            api_key_from_env: false,
+            http_client: http_client.clone(),
+            available_models: Vec::new(),
+            fetch_models_task: None,
+            _subscription: cx.observe_global::<SettingsStore>(|this: &mut State, cx| {
+                this.restart_fetch_models_task(cx);
+                cx.notify();
+            }),
+        });
+
+        Self { http_client, state }
+    }
+
+    fn create_language_model(&self, model: open_router::Model) -> Arc<dyn LanguageModel> {
+        Arc::new(OpenRouterLanguageModel {
+            id: LanguageModelId::from(model.id().to_string()),
+            model,
+            state: self.state.clone(),
+            http_client: self.http_client.clone(),
+            request_limiter: RateLimiter::new(4),
+        })
+    }
+}
+
+impl LanguageModelProviderState for OpenRouterLanguageModelProvider {
+    type ObservableEntity = State;
+
+    fn observable_entity(&self) -> Option<gpui::Entity<Self::ObservableEntity>> {
+        Some(self.state.clone())
+    }
+}
+
+impl LanguageModelProvider for OpenRouterLanguageModelProvider {
+    fn id(&self) -> LanguageModelProviderId {
+        LanguageModelProviderId(PROVIDER_ID.into())
+    }
+
+    fn name(&self) -> LanguageModelProviderName {
+        LanguageModelProviderName(PROVIDER_NAME.into())
+    }
+
+    fn icon(&self) -> IconName {
+        IconName::AiOpenRouter
+    }
+
+    fn default_model(&self, _cx: &App) -> Option<Arc<dyn LanguageModel>> {
+        Some(self.create_language_model(open_router::Model::default()))
+    }
+
+    fn default_fast_model(&self, _cx: &App) -> Option<Arc<dyn LanguageModel>> {
+        Some(self.create_language_model(open_router::Model::default_fast()))
+    }
+
+    fn provided_models(&self, cx: &App) -> Vec<Arc<dyn LanguageModel>> {
+        let mut models_from_api = self.state.read(cx).available_models.clone();
+        let mut settings_models = Vec::new();
+
+        for model in &AllLanguageModelSettings::get_global(cx)
+            .open_router
+            .available_models
+        {
+            settings_models.push(open_router::Model {
+                name: model.name.clone(),
+                display_name: model.display_name.clone(),
+                max_tokens: model.max_tokens,
+                supports_tools: Some(false),
+            });
+        }
+
+        for settings_model in &settings_models {
+            if let Some(pos) = models_from_api
+                .iter()
+                .position(|m| m.name == settings_model.name)
+            {
+                models_from_api[pos] = settings_model.clone();
+            } else {
+                models_from_api.push(settings_model.clone());
+            }
+        }
+
+        models_from_api
+            .into_iter()
+            .map(|model| self.create_language_model(model))
+            .collect()
+    }
+
+    fn is_authenticated(&self, cx: &App) -> bool {
+        self.state.read(cx).is_authenticated()
+    }
+
+    fn authenticate(&self, cx: &mut App) -> Task<Result<(), AuthenticateError>> {
+        self.state.update(cx, |state, cx| state.authenticate(cx))
+    }
+
+    fn configuration_view(&self, window: &mut Window, cx: &mut App) -> AnyView {
+        cx.new(|cx| ConfigurationView::new(self.state.clone(), window, cx))
+            .into()
+    }
+
+    fn reset_credentials(&self, cx: &mut App) -> Task<Result<()>> {
+        self.state.update(cx, |state, cx| state.reset_api_key(cx))
+    }
+}
+
+pub struct OpenRouterLanguageModel {
+    id: LanguageModelId,
+    model: open_router::Model,
+    state: gpui::Entity<State>,
+    http_client: Arc<dyn HttpClient>,
+    request_limiter: RateLimiter,
+}
+
+impl OpenRouterLanguageModel {
+    fn stream_completion(
+        &self,
+        request: open_router::Request,
+        cx: &AsyncApp,
+    ) -> BoxFuture<'static, Result<futures::stream::BoxStream<'static, Result<ResponseStreamEvent>>>>
+    {
+        let http_client = self.http_client.clone();
+        let Ok((api_key, api_url)) = cx.read_entity(&self.state, |state, cx| {
+            let settings = &AllLanguageModelSettings::get_global(cx).open_router;
+            (state.api_key.clone(), settings.api_url.clone())
+        }) else {
+            return futures::future::ready(Err(anyhow!(
+                "App state dropped: Unable to read API key or API URL from the application state"
+            )))
+            .boxed();
+        };
+
+        let future = self.request_limiter.stream(async move {
+            let api_key = api_key.ok_or_else(|| anyhow!("Missing OpenRouter API Key"))?;
+            let request = stream_completion(http_client.as_ref(), &api_url, &api_key, request);
+            let response = request.await?;
+            Ok(response)
+        });
+
+        async move { Ok(future.await?.boxed()) }.boxed()
+    }
+}
+
+impl LanguageModel for OpenRouterLanguageModel {
+    fn id(&self) -> LanguageModelId {
+        self.id.clone()
+    }
+
+    fn name(&self) -> LanguageModelName {
+        LanguageModelName::from(self.model.display_name().to_string())
+    }
+
+    fn provider_id(&self) -> LanguageModelProviderId {
+        LanguageModelProviderId(PROVIDER_ID.into())
+    }
+
+    fn provider_name(&self) -> LanguageModelProviderName {
+        LanguageModelProviderName(PROVIDER_NAME.into())
+    }
+
+    fn supports_tools(&self) -> bool {
+        self.model.supports_tool_calls()
+    }
+
+    fn telemetry_id(&self) -> String {
+        format!("openrouter/{}", self.model.id())
+    }
+
+    fn max_token_count(&self) -> usize {
+        self.model.max_token_count()
+    }
+
+    fn max_output_tokens(&self) -> Option<u32> {
+        self.model.max_output_tokens()
+    }
+
+    fn supports_tool_choice(&self, choice: LanguageModelToolChoice) -> bool {
+        match choice {
+            LanguageModelToolChoice::Auto => true,
+            LanguageModelToolChoice::Any => true,
+            LanguageModelToolChoice::None => true,
+        }
+    }
+
+    fn supports_images(&self) -> bool {
+        false
+    }
+
+    fn count_tokens(
+        &self,
+        request: LanguageModelRequest,
+        cx: &App,
+    ) -> BoxFuture<'static, Result<usize>> {
+        count_open_router_tokens(request, self.model.clone(), cx)
+    }
+
+    fn stream_completion(
+        &self,
+        request: LanguageModelRequest,
+        cx: &AsyncApp,
+    ) -> BoxFuture<
+        'static,
+        Result<
+            futures::stream::BoxStream<
+                'static,
+                Result<LanguageModelCompletionEvent, LanguageModelCompletionError>,
+            >,
+        >,
+    > {
+        let request = into_open_router(request, &self.model, self.max_output_tokens());
+        let completions = self.stream_completion(request, cx);
+        async move {
+            let mapper = OpenRouterEventMapper::new();
+            Ok(mapper.map_stream(completions.await?).boxed())
+        }
+        .boxed()
+    }
+}
+
+pub fn into_open_router(
+    request: LanguageModelRequest,
+    model: &Model,
+    max_output_tokens: Option<u32>,
+) -> open_router::Request {
+    let mut messages = Vec::new();
+    for req_message in request.messages {
+        for content in req_message.content {
+            match content {
+                MessageContent::Text(text) | MessageContent::Thinking { text, .. } => messages
+                    .push(match req_message.role {
+                        Role::User => open_router::RequestMessage::User { content: text },
+                        Role::Assistant => open_router::RequestMessage::Assistant {
+                            content: Some(text),
+                            tool_calls: Vec::new(),
+                        },
+                        Role::System => open_router::RequestMessage::System { content: text },
+                    }),
+                MessageContent::RedactedThinking(_) => {}
+                MessageContent::Image(_) => {}
+                MessageContent::ToolUse(tool_use) => {
+                    let tool_call = open_router::ToolCall {
+                        id: tool_use.id.to_string(),
+                        content: open_router::ToolCallContent::Function {
+                            function: open_router::FunctionContent {
+                                name: tool_use.name.to_string(),
+                                arguments: serde_json::to_string(&tool_use.input)
+                                    .unwrap_or_default(),
+                            },
+                        },
+                    };
+
+                    if let Some(open_router::RequestMessage::Assistant { tool_calls, .. }) =
+                        messages.last_mut()
+                    {
+                        tool_calls.push(tool_call);
+                    } else {
+                        messages.push(open_router::RequestMessage::Assistant {
+                            content: None,
+                            tool_calls: vec![tool_call],
+                        });
+                    }
+                }
+                MessageContent::ToolResult(tool_result) => {
+                    let content = match &tool_result.content {
+                      LanguageModelToolResultContent::Text(text) => {
+                          text.to_string()
+                        }
+                        LanguageModelToolResultContent::Image(_) => {
+                          "[Tool responded with an image, but Zed doesn't support these in Open AI models yet]".to_string()
+                        }
+                    };
+
+                    messages.push(open_router::RequestMessage::Tool {
+                        content: content,
+                        tool_call_id: tool_result.tool_use_id.to_string(),
+                    });
+                }
+            }
+        }
+    }
+
+    open_router::Request {
+        model: model.id().into(),
+        messages,
+        stream: true,
+        stop: request.stop,
+        temperature: request.temperature.unwrap_or(0.4),
+        max_tokens: max_output_tokens,
+        parallel_tool_calls: if model.supports_parallel_tool_calls() && !request.tools.is_empty() {
+            Some(false)
+        } else {
+            None
+        },
+        tools: request
+            .tools
+            .into_iter()
+            .map(|tool| open_router::ToolDefinition::Function {
+                function: open_router::FunctionDefinition {
+                    name: tool.name,
+                    description: Some(tool.description),
+                    parameters: Some(tool.input_schema),
+                },
+            })
+            .collect(),
+        tool_choice: request.tool_choice.map(|choice| match choice {
+            LanguageModelToolChoice::Auto => open_router::ToolChoice::Auto,
+            LanguageModelToolChoice::Any => open_router::ToolChoice::Required,
+            LanguageModelToolChoice::None => open_router::ToolChoice::None,
+        }),
+    }
+}
+
+pub struct OpenRouterEventMapper {
+    tool_calls_by_index: HashMap<usize, RawToolCall>,
+}
+
+impl OpenRouterEventMapper {
+    pub fn new() -> Self {
+        Self {
+            tool_calls_by_index: HashMap::default(),
+        }
+    }
+
+    pub fn map_stream(
+        mut self,
+        events: Pin<Box<dyn Send + Stream<Item = Result<ResponseStreamEvent>>>>,
+    ) -> impl Stream<Item = Result<LanguageModelCompletionEvent, LanguageModelCompletionError>>
+    {
+        events.flat_map(move |event| {
+            futures::stream::iter(match event {
+                Ok(event) => self.map_event(event),
+                Err(error) => vec![Err(LanguageModelCompletionError::Other(anyhow!(error)))],
+            })
+        })
+    }
+
+    pub fn map_event(
+        &mut self,
+        event: ResponseStreamEvent,
+    ) -> Vec<Result<LanguageModelCompletionEvent, LanguageModelCompletionError>> {
+        let Some(choice) = event.choices.first() else {
+            return vec![Err(LanguageModelCompletionError::Other(anyhow!(
+                "Response contained no choices"
+            )))];
+        };
+
+        let mut events = Vec::new();
+        if let Some(content) = choice.delta.content.clone() {
+            events.push(Ok(LanguageModelCompletionEvent::Text(content)));
+        }
+
+        if let Some(tool_calls) = choice.delta.tool_calls.as_ref() {
+            for tool_call in tool_calls {
+                let entry = self.tool_calls_by_index.entry(tool_call.index).or_default();
+
+                if let Some(tool_id) = tool_call.id.clone() {
+                    entry.id = tool_id;
+                }
+
+                if let Some(function) = tool_call.function.as_ref() {
+                    if let Some(name) = function.name.clone() {
+                        entry.name = name;
+                    }
+
+                    if let Some(arguments) = function.arguments.clone() {
+                        entry.arguments.push_str(&arguments);
+                    }
+                }
+            }
+        }
+
+        match choice.finish_reason.as_deref() {
+            Some("stop") => {
+                events.push(Ok(LanguageModelCompletionEvent::Stop(StopReason::EndTurn)));
+            }
+            Some("tool_calls") => {
+                events.extend(self.tool_calls_by_index.drain().map(|(_, tool_call)| {
+                    match serde_json::Value::from_str(&tool_call.arguments) {
+                        Ok(input) => Ok(LanguageModelCompletionEvent::ToolUse(
+                            LanguageModelToolUse {
+                                id: tool_call.id.clone().into(),
+                                name: tool_call.name.as_str().into(),
+                                is_input_complete: true,
+                                input,
+                                raw_input: tool_call.arguments.clone(),
+                            },
+                        )),
+                        Err(error) => Err(LanguageModelCompletionError::BadInputJson {
+                            id: tool_call.id.into(),
+                            tool_name: tool_call.name.as_str().into(),
+                            raw_input: tool_call.arguments.into(),
+                            json_parse_error: error.to_string(),
+                        }),
+                    }
+                }));
+
+                events.push(Ok(LanguageModelCompletionEvent::Stop(StopReason::ToolUse)));
+            }
+            Some(stop_reason) => {
+                log::error!("Unexpected OpenAI stop_reason: {stop_reason:?}",);
+                events.push(Ok(LanguageModelCompletionEvent::Stop(StopReason::EndTurn)));
+            }
+            None => {}
+        }
+
+        events
+    }
+}
+
+#[derive(Default)]
+struct RawToolCall {
+    id: String,
+    name: String,
+    arguments: String,
+}
+
+pub fn count_open_router_tokens(
+    request: LanguageModelRequest,
+    _model: open_router::Model,
+    cx: &App,
+) -> BoxFuture<'static, Result<usize>> {
+    cx.background_spawn(async move {
+        let messages = request
+            .messages
+            .into_iter()
+            .map(|message| tiktoken_rs::ChatCompletionRequestMessage {
+                role: match message.role {
+                    Role::User => "user".into(),
+                    Role::Assistant => "assistant".into(),
+                    Role::System => "system".into(),
+                },
+                content: Some(message.string_contents()),
+                name: None,
+                function_call: None,
+            })
+            .collect::<Vec<_>>();
+
+        tiktoken_rs::num_tokens_from_messages("gpt-4o", &messages)
+    })
+    .boxed()
+}
+
+struct ConfigurationView {
+    api_key_editor: Entity<Editor>,
+    state: gpui::Entity<State>,
+    load_credentials_task: Option<Task<()>>,
+}
+
+impl ConfigurationView {
+    fn new(state: gpui::Entity<State>, window: &mut Window, cx: &mut Context<Self>) -> Self {
+        let api_key_editor = cx.new(|cx| {
+            let mut editor = Editor::single_line(window, cx);
+            editor
+                .set_placeholder_text("sk_or_000000000000000000000000000000000000000000000000", cx);
+            editor
+        });
+
+        cx.observe(&state, |_, _, cx| {
+            cx.notify();
+        })
+        .detach();
+
+        let load_credentials_task = Some(cx.spawn_in(window, {
+            let state = state.clone();
+            async move |this, cx| {
+                if let Some(task) = state
+                    .update(cx, |state, cx| state.authenticate(cx))
+                    .log_err()
+                {
+                    let _ = task.await;
+                }
+
+                this.update(cx, |this, cx| {
+                    this.load_credentials_task = None;
+                    cx.notify();
+                })
+                .log_err();
+            }
+        }));
+
+        Self {
+            api_key_editor,
+            state,
+            load_credentials_task,
+        }
+    }
+
+    fn save_api_key(&mut self, _: &menu::Confirm, window: &mut Window, cx: &mut Context<Self>) {
+        let api_key = self.api_key_editor.read(cx).text(cx);
+        if api_key.is_empty() {
+            return;
+        }
+
+        let state = self.state.clone();
+        cx.spawn_in(window, async move |_, cx| {
+            state
+                .update(cx, |state, cx| state.set_api_key(api_key, cx))?
+                .await
+        })
+        .detach_and_log_err(cx);
+
+        cx.notify();
+    }
+
+    fn reset_api_key(&mut self, window: &mut Window, cx: &mut Context<Self>) {
+        self.api_key_editor
+            .update(cx, |editor, cx| editor.set_text("", window, cx));
+
+        let state = self.state.clone();
+        cx.spawn_in(window, async move |_, cx| {
+            state.update(cx, |state, cx| state.reset_api_key(cx))?.await
+        })
+        .detach_and_log_err(cx);
+
+        cx.notify();
+    }
+
+    fn render_api_key_editor(&self, cx: &mut Context<Self>) -> impl IntoElement {
+        let settings = ThemeSettings::get_global(cx);
+        let text_style = TextStyle {
+            color: cx.theme().colors().text,
+            font_family: settings.ui_font.family.clone(),
+            font_features: settings.ui_font.features.clone(),
+            font_fallbacks: settings.ui_font.fallbacks.clone(),
+            font_size: rems(0.875).into(),
+            font_weight: settings.ui_font.weight,
+            font_style: FontStyle::Normal,
+            line_height: relative(1.3),
+            white_space: WhiteSpace::Normal,
+            ..Default::default()
+        };
+        EditorElement::new(
+            &self.api_key_editor,
+            EditorStyle {
+                background: cx.theme().colors().editor_background,
+                local_player: cx.theme().players().local(),
+                text: text_style,
+                ..Default::default()
+            },
+        )
+    }
+
+    fn should_render_editor(&self, cx: &mut Context<Self>) -> bool {
+        !self.state.read(cx).is_authenticated()
+    }
+}
+
+impl Render for ConfigurationView {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let env_var_set = self.state.read(cx).api_key_from_env;
+
+        if self.load_credentials_task.is_some() {
+            div().child(Label::new("Loading credentials...")).into_any()
+        } else if self.should_render_editor(cx) {
+            v_flex()
+                .size_full()
+                .on_action(cx.listener(Self::save_api_key))
+                .child(Label::new("To use Zed's assistant with OpenRouter, you need to add an API key. Follow these steps:"))
+                .child(
+                    List::new()
+                        .child(InstructionListItem::new(
+                            "Create an API key by visiting",
+                            Some("OpenRouter's console"),
+                            Some("https://openrouter.ai/keys"),
+                        ))
+                        .child(InstructionListItem::text_only(
+                            "Ensure your OpenRouter account has credits",
+                        ))
+                        .child(InstructionListItem::text_only(
+                            "Paste your API key below and hit enter to start using the assistant",
+                        )),
+                )
+                .child(
+                    h_flex()
+                        .w_full()
+                        .my_2()
+                        .px_2()
+                        .py_1()
+                        .bg(cx.theme().colors().editor_background)
+                        .border_1()
+                        .border_color(cx.theme().colors().border)
+                        .rounded_sm()
+                        .child(self.render_api_key_editor(cx)),
+                )
+                .child(
+                    Label::new(
+                        format!("You can also assign the {OPENROUTER_API_KEY_VAR} environment variable and restart Zed."),
+                    )
+                    .size(LabelSize::Small).color(Color::Muted),
+                )
+                .into_any()
+        } else {
+            h_flex()
+                .mt_1()
+                .p_1()
+                .justify_between()
+                .rounded_md()
+                .border_1()
+                .border_color(cx.theme().colors().border)
+                .bg(cx.theme().colors().background)
+                .child(
+                    h_flex()
+                        .gap_1()
+                        .child(Icon::new(IconName::Check).color(Color::Success))
+                        .child(Label::new(if env_var_set {
+                            format!("API key set in {OPENROUTER_API_KEY_VAR} environment variable.")
+                        } else {
+                            "API key configured.".to_string()
+                        })),
+                )
+                .child(
+                    Button::new("reset-key", "Reset Key")
+                        .label_size(LabelSize::Small)
+                        .icon(Some(IconName::Trash))
+                        .icon_size(IconSize::Small)
+                        .icon_position(IconPosition::Start)
+                        .disabled(env_var_set)
+                        .when(env_var_set, |this| {
+                            this.tooltip(Tooltip::text(format!("To reset your API key, unset the {OPENROUTER_API_KEY_VAR} environment variable.")))
+                        })
+                        .on_click(cx.listener(|this, _, window, cx| this.reset_api_key(window, cx))),
+                )
+                .into_any()
+        }
+    }
+}

crates/language_models/src/settings.rs

@@ -20,6 +20,7 @@ use crate::provider::{
     mistral::MistralSettings,
     ollama::OllamaSettings,
     open_ai::OpenAiSettings,
+    open_router::OpenRouterSettings,
 };
 
 /// Initializes the language model settings.
@@ -61,6 +62,7 @@ pub struct AllLanguageModelSettings {
     pub bedrock: AmazonBedrockSettings,
     pub ollama: OllamaSettings,
     pub openai: OpenAiSettings,
+    pub open_router: OpenRouterSettings,
     pub zed_dot_dev: ZedDotDevSettings,
     pub google: GoogleSettings,
     pub copilot_chat: CopilotChatSettings,
@@ -76,6 +78,7 @@ pub struct AllLanguageModelSettingsContent {
     pub ollama: Option<OllamaSettingsContent>,
     pub lmstudio: Option<LmStudioSettingsContent>,
     pub openai: Option<OpenAiSettingsContent>,
+    pub open_router: Option<OpenRouterSettingsContent>,
     #[serde(rename = "zed.dev")]
     pub zed_dot_dev: Option<ZedDotDevSettingsContent>,
     pub google: Option<GoogleSettingsContent>,
@@ -271,6 +274,12 @@ pub struct ZedDotDevSettingsContent {
 #[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
 pub struct CopilotChatSettingsContent {}
 
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+pub struct OpenRouterSettingsContent {
+    pub api_url: Option<String>,
+    pub available_models: Option<Vec<provider::open_router::AvailableModel>>,
+}
+
 impl settings::Settings for AllLanguageModelSettings {
     const KEY: Option<&'static str> = Some("language_models");
 
@@ -409,6 +418,19 @@ impl settings::Settings for AllLanguageModelSettings {
                 &mut settings.mistral.available_models,
                 mistral.as_ref().and_then(|s| s.available_models.clone()),
             );
+
+            // OpenRouter
+            let open_router = value.open_router.clone();
+            merge(
+                &mut settings.open_router.api_url,
+                open_router.as_ref().and_then(|s| s.api_url.clone()),
+            );
+            merge(
+                &mut settings.open_router.available_models,
+                open_router
+                    .as_ref()
+                    .and_then(|s| s.available_models.clone()),
+            );
         }
 
         Ok(settings)

crates/open_router/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "open_router"
+version = "0.1.0"
+edition.workspace = true
+publish.workspace = true
+license = "GPL-3.0-or-later"
+
+[lints]
+workspace = true
+
+[lib]
+path = "src/open_router.rs"
+
+[features]
+default = []
+schemars = ["dep:schemars"]
+
+[dependencies]
+anyhow.workspace = true
+futures.workspace = true
+http_client.workspace = true
+schemars = { workspace = true, optional = true }
+serde.workspace = true
+serde_json.workspace = true
+workspace-hack.workspace = true

crates/open_router/LICENSE-GPL

@@ -0,0 +1 @@
+../../LICENSE-GPL

crates/open_router/src/open_router.rs

@@ -0,0 +1,484 @@
+use anyhow::{Context, Result, anyhow};
+use futures::{AsyncBufReadExt, AsyncReadExt, StreamExt, io::BufReader, stream::BoxStream};
+use http_client::{AsyncBody, HttpClient, Method, Request as HttpRequest};
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use std::convert::TryFrom;
+
+pub const OPEN_ROUTER_API_URL: &str = "https://openrouter.ai/api/v1";
+
+fn is_none_or_empty<T: AsRef<[U]>, U>(opt: &Option<T>) -> bool {
+    opt.as_ref().map_or(true, |v| v.as_ref().is_empty())
+}
+
+#[derive(Clone, Copy, Serialize, Deserialize, Debug, Eq, PartialEq)]
+#[serde(rename_all = "lowercase")]
+pub enum Role {
+    User,
+    Assistant,
+    System,
+    Tool,
+}
+
+impl TryFrom<String> for Role {
+    type Error = anyhow::Error;
+
+    fn try_from(value: String) -> Result<Self> {
+        match value.as_str() {
+            "user" => Ok(Self::User),
+            "assistant" => Ok(Self::Assistant),
+            "system" => Ok(Self::System),
+            "tool" => Ok(Self::Tool),
+            _ => Err(anyhow!("invalid role '{value}'")),
+        }
+    }
+}
+
+impl From<Role> for String {
+    fn from(val: Role) -> Self {
+        match val {
+            Role::User => "user".to_owned(),
+            Role::Assistant => "assistant".to_owned(),
+            Role::System => "system".to_owned(),
+            Role::Tool => "tool".to_owned(),
+        }
+    }
+}
+
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq)]
+pub struct Model {
+    pub name: String,
+    pub display_name: Option<String>,
+    pub max_tokens: usize,
+    pub supports_tools: Option<bool>,
+}
+
+impl Model {
+    pub fn default_fast() -> Self {
+        Self::new(
+            "openrouter/auto",
+            Some("Auto Router"),
+            Some(2000000),
+            Some(true),
+        )
+    }
+
+    pub fn default() -> Self {
+        Self::default_fast()
+    }
+
+    pub fn new(
+        name: &str,
+        display_name: Option<&str>,
+        max_tokens: Option<usize>,
+        supports_tools: Option<bool>,
+    ) -> Self {
+        Self {
+            name: name.to_owned(),
+            display_name: display_name.map(|s| s.to_owned()),
+            max_tokens: max_tokens.unwrap_or(2000000),
+            supports_tools,
+        }
+    }
+
+    pub fn id(&self) -> &str {
+        &self.name
+    }
+
+    pub fn display_name(&self) -> &str {
+        self.display_name.as_ref().unwrap_or(&self.name)
+    }
+
+    pub fn max_token_count(&self) -> usize {
+        self.max_tokens
+    }
+
+    pub fn max_output_tokens(&self) -> Option<u32> {
+        None
+    }
+
+    pub fn supports_tool_calls(&self) -> bool {
+        self.supports_tools.unwrap_or(false)
+    }
+
+    pub fn supports_parallel_tool_calls(&self) -> bool {
+        false
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Request {
+    pub model: String,
+    pub messages: Vec<RequestMessage>,
+    pub stream: bool,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub max_tokens: Option<u32>,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub stop: Vec<String>,
+    pub temperature: f32,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub tool_choice: Option<ToolChoice>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub parallel_tool_calls: Option<bool>,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub tools: Vec<ToolDefinition>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(untagged)]
+pub enum ToolChoice {
+    Auto,
+    Required,
+    None,
+    Other(ToolDefinition),
+}
+
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+#[derive(Clone, Deserialize, Serialize, Debug)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum ToolDefinition {
+    #[allow(dead_code)]
+    Function { function: FunctionDefinition },
+}
+
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct FunctionDefinition {
+    pub name: String,
+    pub description: Option<String>,
+    pub parameters: Option<Value>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+#[serde(tag = "role", rename_all = "lowercase")]
+pub enum RequestMessage {
+    Assistant {
+        content: Option<String>,
+        #[serde(default, skip_serializing_if = "Vec::is_empty")]
+        tool_calls: Vec<ToolCall>,
+    },
+    User {
+        content: String,
+    },
+    System {
+        content: String,
+    },
+    Tool {
+        content: String,
+        tool_call_id: String,
+    },
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct ToolCall {
+    pub id: String,
+    #[serde(flatten)]
+    pub content: ToolCallContent,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+#[serde(tag = "type", rename_all = "lowercase")]
+pub enum ToolCallContent {
+    Function { function: FunctionContent },
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct FunctionContent {
+    pub name: String,
+    pub arguments: String,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct ResponseMessageDelta {
+    pub role: Option<Role>,
+    pub content: Option<String>,
+    #[serde(default, skip_serializing_if = "is_none_or_empty")]
+    pub tool_calls: Option<Vec<ToolCallChunk>>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct ToolCallChunk {
+    pub index: usize,
+    pub id: Option<String>,
+    pub function: Option<FunctionChunk>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
+pub struct FunctionChunk {
+    pub name: Option<String>,
+    pub arguments: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Usage {
+    pub prompt_tokens: u32,
+    pub completion_tokens: u32,
+    pub total_tokens: u32,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct ChoiceDelta {
+    pub index: u32,
+    pub delta: ResponseMessageDelta,
+    pub finish_reason: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct ResponseStreamEvent {
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub id: Option<String>,
+    pub created: u32,
+    pub model: String,
+    pub choices: Vec<ChoiceDelta>,
+    pub usage: Option<Usage>,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Response {
+    pub id: String,
+    pub object: String,
+    pub created: u64,
+    pub model: String,
+    pub choices: Vec<Choice>,
+    pub usage: Usage,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Choice {
+    pub index: u32,
+    pub message: RequestMessage,
+    pub finish_reason: Option<String>,
+}
+
+#[derive(Default, Debug, Clone, PartialEq, Deserialize)]
+pub struct ListModelsResponse {
+    pub data: Vec<ModelEntry>,
+}
+
+#[derive(Default, Debug, Clone, PartialEq, Deserialize)]
+pub struct ModelEntry {
+    pub id: String,
+    pub name: String,
+    pub created: usize,
+    pub description: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub context_length: Option<usize>,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub supported_parameters: Vec<String>,
+}
+
+pub async fn complete(
+    client: &dyn HttpClient,
+    api_url: &str,
+    api_key: &str,
+    request: Request,
+) -> Result<Response> {
+    let uri = format!("{api_url}/chat/completions");
+    let request_builder = HttpRequest::builder()
+        .method(Method::POST)
+        .uri(uri)
+        .header("Content-Type", "application/json")
+        .header("Authorization", format!("Bearer {}", api_key))
+        .header("HTTP-Referer", "https://zed.dev")
+        .header("X-Title", "Zed Editor");
+
+    let mut request_body = request;
+    request_body.stream = false;
+
+    let request = request_builder.body(AsyncBody::from(serde_json::to_string(&request_body)?))?;
+    let mut response = client.send(request).await?;
+
+    if response.status().is_success() {
+        let mut body = String::new();
+        response.body_mut().read_to_string(&mut body).await?;
+        let response: Response = serde_json::from_str(&body)?;
+        Ok(response)
+    } else {
+        let mut body = String::new();
+        response.body_mut().read_to_string(&mut body).await?;
+
+        #[derive(Deserialize)]
+        struct OpenRouterResponse {
+            error: OpenRouterError,
+        }
+
+        #[derive(Deserialize)]
+        struct OpenRouterError {
+            message: String,
+            #[serde(default)]
+            code: String,
+        }
+
+        match serde_json::from_str::<OpenRouterResponse>(&body) {
+            Ok(response) if !response.error.message.is_empty() => {
+                let error_message = if !response.error.code.is_empty() {
+                    format!("{}: {}", response.error.code, response.error.message)
+                } else {
+                    response.error.message
+                };
+
+                Err(anyhow!(
+                    "Failed to connect to OpenRouter API: {}",
+                    error_message
+                ))
+            }
+            _ => Err(anyhow!(
+                "Failed to connect to OpenRouter API: {} {}",
+                response.status(),
+                body,
+            )),
+        }
+    }
+}
+
+pub async fn stream_completion(
+    client: &dyn HttpClient,
+    api_url: &str,
+    api_key: &str,
+    request: Request,
+) -> Result<BoxStream<'static, Result<ResponseStreamEvent>>> {
+    let uri = format!("{api_url}/chat/completions");
+    let request_builder = HttpRequest::builder()
+        .method(Method::POST)
+        .uri(uri)
+        .header("Content-Type", "application/json")
+        .header("Authorization", format!("Bearer {}", api_key))
+        .header("HTTP-Referer", "https://zed.dev")
+        .header("X-Title", "Zed Editor");
+
+    let request = request_builder.body(AsyncBody::from(serde_json::to_string(&request)?))?;
+    let mut response = client.send(request).await?;
+
+    if response.status().is_success() {
+        let reader = BufReader::new(response.into_body());
+        Ok(reader
+            .lines()
+            .filter_map(|line| async move {
+                match line {
+                    Ok(line) => {
+                        if line.starts_with(':') {
+                            return None;
+                        }
+
+                        let line = line.strip_prefix("data: ")?;
+                        if line == "[DONE]" {
+                            None
+                        } else {
+                            match serde_json::from_str::<ResponseStreamEvent>(line) {
+                                Ok(response) => Some(Ok(response)),
+                                Err(error) => {
+                                    #[derive(Deserialize)]
+                                    struct ErrorResponse {
+                                        error: String,
+                                    }
+
+                                    match serde_json::from_str::<ErrorResponse>(line) {
+                                        Ok(err_response) => Some(Err(anyhow!(err_response.error))),
+                                        Err(_) => {
+                                            if line.trim().is_empty() {
+                                                None
+                                            } else {
+                                                Some(Err(anyhow!(
+                                                    "Failed to parse response: {}. Original content: '{}'",
+                                                    error, line
+                                                )))
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    Err(error) => Some(Err(anyhow!(error))),
+                }
+            })
+            .boxed())
+    } else {
+        let mut body = String::new();
+        response.body_mut().read_to_string(&mut body).await?;
+
+        #[derive(Deserialize)]
+        struct OpenRouterResponse {
+            error: OpenRouterError,
+        }
+
+        #[derive(Deserialize)]
+        struct OpenRouterError {
+            message: String,
+            #[serde(default)]
+            code: String,
+        }
+
+        match serde_json::from_str::<OpenRouterResponse>(&body) {
+            Ok(response) if !response.error.message.is_empty() => {
+                let error_message = if !response.error.code.is_empty() {
+                    format!("{}: {}", response.error.code, response.error.message)
+                } else {
+                    response.error.message
+                };
+
+                Err(anyhow!(
+                    "Failed to connect to OpenRouter API: {}",
+                    error_message
+                ))
+            }
+            _ => Err(anyhow!(
+                "Failed to connect to OpenRouter API: {} {}",
+                response.status(),
+                body,
+            )),
+        }
+    }
+}
+
+pub async fn list_models(client: &dyn HttpClient, api_url: &str) -> Result<Vec<Model>> {
+    let uri = format!("{api_url}/models");
+    let request_builder = HttpRequest::builder()
+        .method(Method::GET)
+        .uri(uri)
+        .header("Accept", "application/json");
+
+    let request = request_builder.body(AsyncBody::default())?;
+    let mut response = client.send(request).await?;
+
+    let mut body = String::new();
+    response.body_mut().read_to_string(&mut body).await?;
+
+    if response.status().is_success() {
+        let response: ListModelsResponse =
+            serde_json::from_str(&body).context("Unable to parse OpenRouter models response")?;
+
+        let models = response
+            .data
+            .into_iter()
+            .map(|entry| Model {
+                name: entry.id,
+                // OpenRouter returns display names in the format "provider_name: model_name".
+                // When displayed in the UI, these names can get truncated from the right.
+                // Since users typically already know the provider, we extract just the model name
+                // portion (after the colon) to create a more concise and user-friendly label
+                // for the model dropdown in the agent panel.
+                display_name: Some(
+                    entry
+                        .name
+                        .split(':')
+                        .next_back()
+                        .unwrap_or(&entry.name)
+                        .trim()
+                        .to_string(),
+                ),
+                max_tokens: entry.context_length.unwrap_or(2000000),
+                supports_tools: Some(entry.supported_parameters.contains(&"tools".to_string())),
+            })
+            .collect();
+
+        Ok(models)
+    } else {
+        Err(anyhow!(
+            "Failed to connect to OpenRouter API: {} {}",
+            response.status(),
+            body,
+        ))
+    }
+}