feat: read model_provider and model_providers from config.toml (#853)

This is the first step in supporting other model providers in the Rust CLI. Specifically, this PR adds support for the new entries in `Config` and `ConfigOverrides` to specify a `ModelProviderInfo`, which is the basic config needed for an LLM provider. This PR does not get us all the way there yet because `client.rs` still categorically appends `/responses` to the URL and expects the endpoint to support the OpenAI Responses API. Will fix that next!
2025-05-07 17:38:28 -07:00
parent cfe50c7107
commit 86022f097e
12 changed files with 208 additions and 30 deletions
--- a/codex-rs/core/src/model_provider_info.rs
+++ b/codex-rs/core/src/model_provider_info.rs
@@ -0,0 +1,103 @@
+//! Registry of model providers supported by Codex.
+//!
+//! Providers can be defined in two places:
+//!   1. Built-in defaults compiled into the binary so Codex works out-of-the-box.
+//!   2. User-defined entries inside `~/.codex/config.toml` under the `model_providers`
+//!      key. These override or extend the defaults at runtime.
+
+use serde::Deserialize;
+use serde::Serialize;
+use std::collections::HashMap;
+
+/// Serializable representation of a provider definition.
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct ModelProviderInfo {
+    /// Friendly display name.
+    pub name: String,
+    /// Base URL for the provider's OpenAI-compatible API.
+    pub base_url: String,
+    /// Environment variable that stores the user's API key for this provider.
+    pub env_key: String,
+}
+
+impl ModelProviderInfo {
+    /// Returns the API key for this provider if present in the environment.
+    pub fn api_key(&self) -> Option<String> {
+        std::env::var(&self.env_key).ok()
+    }
+}
+
+/// Built-in default provider list.
+pub fn built_in_model_providers() -> HashMap<String, ModelProviderInfo> {
+    use ModelProviderInfo as P;
+
+    [
+        (
+            "openai",
+            P {
+                name: "OpenAI".into(),
+                base_url: "https://api.openai.com/v1".into(),
+                env_key: "OPENAI_API_KEY".into(),
+            },
+        ),
+        (
+            "openrouter",
+            P {
+                name: "OpenRouter".into(),
+                base_url: "https://openrouter.ai/api/v1".into(),
+                env_key: "OPENROUTER_API_KEY".into(),
+            },
+        ),
+        (
+            "gemini",
+            P {
+                name: "Gemini".into(),
+                base_url: "https://generativelanguage.googleapis.com/v1beta/openai".into(),
+                env_key: "GEMINI_API_KEY".into(),
+            },
+        ),
+        (
+            "ollama",
+            P {
+                name: "Ollama".into(),
+                base_url: "http://localhost:11434/v1".into(),
+                env_key: "OLLAMA_API_KEY".into(),
+            },
+        ),
+        (
+            "mistral",
+            P {
+                name: "Mistral".into(),
+                base_url: "https://api.mistral.ai/v1".into(),
+                env_key: "MISTRAL_API_KEY".into(),
+            },
+        ),
+        (
+            "deepseek",
+            P {
+                name: "DeepSeek".into(),
+                base_url: "https://api.deepseek.com".into(),
+                env_key: "DEEPSEEK_API_KEY".into(),
+            },
+        ),
+        (
+            "xai",
+            P {
+                name: "xAI".into(),
+                base_url: "https://api.x.ai/v1".into(),
+                env_key: "XAI_API_KEY".into(),
+            },
+        ),
+        (
+            "groq",
+            P {
+                name: "Groq".into(),
+                base_url: "https://api.groq.com/openai/v1".into(),
+                env_key: "GROQ_API_KEY".into(),
+            },
+        ),
+    ]
+    .into_iter()
+    .map(|(k, v)| (k.to_string(), v))
+    .collect()
+}