feat: support claude (#278)

2 files changed, 172 insertions, 0 deletions

diff --git a/src/client/claude.rs b/src/client/claude.rs
new file mode 100644
index 0000000..920a695
--- /dev/null
+++ b/src/client/claude.rs
@@ -0,0 +1,171 @@
+use super::{
+    patch_system_message, ClaudeClient, Client, ExtraConfig, Model, PromptType, SendData,
+    TokensCountFactors,
+};
+
+use crate::{render::ReplyHandler, utils::PromptKind};
+
+use anyhow::{anyhow, bail, Result};
+use async_trait::async_trait;
+use futures_util::StreamExt;
+use reqwest::{Client as ReqwestClient, RequestBuilder};
+use reqwest_eventsource::{Error as EventSourceError, Event, RequestBuilderExt};
+use serde::Deserialize;
+use serde_json::{json, Value};
+
+const API_BASE: &str = "https://api.anthropic.com/v1/messages";
+
+const MODELS: [(&str, usize, &str); 3] = [
+    ("claude-2.1", 204096, "text"),
+    ("claude-2.0", 104096, "text"),
+    ("claude-instant-1.2", 104096, "text"),
+];
+
+const TOKENS_COUNT_FACTORS: TokensCountFactors = (5, 2);
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct ClaudeConfig {
+    pub name: Option<String>,
+    pub api_key: Option<String>,
+    pub extra: Option<ExtraConfig>,
+}
+
+#[async_trait]
+impl Client for ClaudeClient {
+    client_common_fns!();
+
+    async fn send_message_inner(&self, client: &ReqwestClient, data: SendData) -> Result<String> {
+        let builder = self.request_builder(client, data)?;
+        send_message(builder).await
+    }
+
+    async fn send_message_streaming_inner(
+        &self,
+        client: &ReqwestClient,
+        handler: &mut ReplyHandler,
+        data: SendData,
+    ) -> Result<()> {
+        let builder = self.request_builder(client, data)?;
+        send_message_streaming(builder, handler).await
+    }
+}
+
+impl ClaudeClient {
+    config_get_fn!(api_key, get_api_key);
+
+    pub const PROMPTS: [PromptType<'static>; 1] =
+        [("api_key", "API Key:", false, PromptKind::String)];
+
+    pub fn list_models(local_config: &ClaudeConfig) -> Vec<Model> {
+        let client_name = Self::name(local_config);
+        MODELS
+            .into_iter()
+            .map(|(name, max_tokens, capabilities)| {
+                Model::new(client_name, name)
+                    .set_capabilities(capabilities.into())
+                    .set_max_tokens(Some(max_tokens))
+                    .set_tokens_count_factors(TOKENS_COUNT_FACTORS)
+            })
+            .collect()
+    }
+
+    fn request_builder(&self, client: &ReqwestClient, data: SendData) -> Result<RequestBuilder> {
+        let api_key = self.get_api_key().ok();
+
+        let body = build_body(data, self.model.name.clone());
+
+        let url = API_BASE;
+
+        debug!("Claude Request: {url} {body}");
+
+        let mut builder = client.post(url).json(&body);
+        builder = builder.header("anthropic-version", "2023-06-01");
+        if let Some(api_key) = api_key {
+            builder = builder.header("x-api-key", api_key)
+        }
+
+        Ok(builder)
+    }
+}
+
+async fn send_message(builder: RequestBuilder) -> Result<String> {
+    let data: Value = builder.send().await?.json().await?;
+    check_error(&data)?;
+
+    let output = data["content"][0]["text"]
+        .as_str()
+        .ok_or_else(|| anyhow!("Invalid response data: {data}"))?;
+
+    Ok(output.to_string())
+}
+
+async fn send_message_streaming(builder: RequestBuilder, handler: &mut ReplyHandler) -> Result<()> {
+    let mut es = builder.eventsource()?;
+    while let Some(event) = es.next().await {
+        match event {
+            Ok(Event::Open) => {}
+            Ok(Event::Message(message)) => {
+                let data: Value = serde_json::from_str(&message.data)?;
+                check_error(&data)?;
+                if let Some(typ) = data["type"].as_str() {
+                    if typ == "content_block_delta" {
+                        if let Some(text) = data["delta"]["text"].as_str() {
+                            handler.text(text)?;
+                        }
+                    }
+                }
+            }
+            Err(err) => {
+                match err {
+                    EventSourceError::StreamEnded => {}
+                    EventSourceError::InvalidStatusCode(code, res) => {
+                        let data: Value = res.json().await?;
+                        check_error(&data)?;
+                        bail!("Invalid status code: {code}");
+                    }
+                    _ => {
+                        bail!("{}", err);
+                    }
+                }
+                es.close();
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn build_body(data: SendData, model: String) -> Value {
+    let SendData {
+        mut messages,
+        temperature,
+        stream,
+    } = data;
+
+    patch_system_message(&mut messages);
+
+    let mut body = json!({
+        "model": model,
+        "max_tokens": 4096,
+        "messages": messages,
+    });
+
+    if let Some(v) = temperature {
+        body["temperature"] = (v / 2.0).into();
+    }
+    if stream {
+        body["stream"] = true.into();
+    }
+    body
+}
+
+fn check_error(data: &Value) -> Result<()> {
+    if let Some(error) = data["error"].as_object() {
+        if let (Some(typ), Some(message)) = (error["type"].as_str(), error["message"].as_str()) {
+            bail!("{typ}: {message}");
+        } else {
+            bail!("{}", Value::Object(error.clone()))
+        }
+    }
+    Ok(())
+}
diff --git a/src/client/mod.rs b/src/client/mod.rs
index 320ddc4..1517b93 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -10,6 +10,7 @@ pub use model::*;
 register_client!(
     (openai, "openai", OpenAIConfig, OpenAIClient),
     (gemini, "gemini", GeminiConfig, GeminiClient),
+    (claude, "claude", ClaudeConfig, ClaudeClient),
     (localai, "localai", LocalAIConfig, LocalAIClient),
     (ollama, "ollama", OllamaConfig, OllamaClient),
     (