Implement open ai api llm backend

crates/factor-llm/src/spin.rs

@@ -2,7 +2,7 @@ use std::path::PathBuf;
 use std::sync::Arc;
 
 use spin_factors::runtime_config::toml::GetTomlValue;
-use spin_llm_remote_http::RemoteHttpLlmEngine;
+use spin_llm_remote_http::{ApiType, RemoteHttpLlmEngine};
 use spin_world::async_trait;
 use spin_world::v1::llm::{self as v1};
 use spin_world::v2::llm::{self as v2};
@@ -122,6 +122,7 @@ impl LlmCompute {
             LlmCompute::RemoteHttp(config) => Arc::new(Mutex::new(RemoteHttpLlmEngine::new(
                 config.url,
                 config.auth_token,
+                config.api_type,
             ))),
         };
         Ok(engine)
@@ -132,6 +133,8 @@ impl LlmCompute {
 pub struct RemoteHttpCompute {
     url: Url,
     auth_token: String,
+    #[serde(default)]
+    api_type: ApiType,
 }
 
 /// A noop engine used when the local engine feature is disabled.

crates/llm-remote-http/src/default.rs

@@ -0,0 +1,136 @@
+use anyhow::Result;
+use reqwest::{
+    header::{HeaderMap, HeaderValue},
+    Client, Url,
+};
+use serde_json::json;
+use spin_world::{
+    async_trait,
+    v2::llm::{self as wasi_llm},
+};
+
+use crate::{EmbeddingResponseBody, InferRequestBodyParams, InferResponseBody, LlmWorker};
+
+pub(crate) struct DefaultAgentEngine {
+    auth_token: String,
+    url: Url,
+    client: Option<Client>,
+}
+
+impl DefaultAgentEngine {
+    pub fn new(auth_token: String, url: Url, client: Option<Client>) -> Self {
+        Self {
+            auth_token,
+            url,
+            client,
+        }
+    }
+}
+
+#[async_trait]
+impl LlmWorker for DefaultAgentEngine {
+    async fn infer(
+        &mut self,
+        model: wasi_llm::InferencingModel,
+        prompt: String,
+        params: wasi_llm::InferencingParams,
+    ) -> Result<wasi_llm::InferencingResult, wasi_llm::Error> {
+        let client = self.client.get_or_insert_with(Default::default);
+
+        let mut headers = HeaderMap::new();
+        headers.insert(
+            "authorization",
+            HeaderValue::from_str(&format!("bearer {}", self.auth_token)).map_err(|_| {
+                wasi_llm::Error::RuntimeError("Failed to create authorization header".to_string())
+            })?,
+        );
+        spin_telemetry::inject_trace_context(&mut headers);
+
+        let inference_options = InferRequestBodyParams {
+            max_tokens: params.max_tokens,
+            repeat_penalty: params.repeat_penalty,
+            repeat_penalty_last_n_token_count: params.repeat_penalty_last_n_token_count,
+            temperature: params.temperature,
+            top_k: params.top_k,
+            top_p: params.top_p,
+        };
+        let body = serde_json::to_string(&json!({
+            "model": model,
+            "prompt": prompt,
+            "options": inference_options
+        }))
+        .map_err(|_| wasi_llm::Error::RuntimeError("Failed to serialize JSON".to_string()))?;
+
+        let infer_url = self
+            .url
+            .join("/infer")
+            .map_err(|_| wasi_llm::Error::RuntimeError("Failed to create URL".to_string()))?;
+        tracing::info!("Sending remote inference request to {infer_url}");
+
+        let resp = client
+            .request(reqwest::Method::POST, infer_url)
+            .headers(headers)
+            .body(body)
+            .send()
+            .await
+            .map_err(|err| {
+                wasi_llm::Error::RuntimeError(format!("POST /infer request error: {err}"))
+            })?;
+
+        match resp.json::<InferResponseBody>().await {
+            Ok(val) => Ok(val.into()),
+            Err(err) => Err(wasi_llm::Error::RuntimeError(format!(
+                "Failed to deserialize response for \"POST  /index\": {err}"
+            ))),
+        }
+    }
+
+    async fn generate_embeddings(
+        &mut self,
+        model: wasi_llm::EmbeddingModel,
+        data: Vec<String>,
+    ) -> Result<wasi_llm::EmbeddingsResult, wasi_llm::Error> {
+        let client = self.client.get_or_insert_with(Default::default);
+
+        let mut headers = HeaderMap::new();
+        headers.insert(
+            "authorization",
+            HeaderValue::from_str(&format!("bearer {}", self.auth_token)).map_err(|_| {
+                wasi_llm::Error::RuntimeError("Failed to create authorization header".to_string())
+            })?,
+        );
+        spin_telemetry::inject_trace_context(&mut headers);
+
+        let body = serde_json::to_string(&json!({
+            "model": model,
+            "input": data
+        }))
+        .map_err(|_| wasi_llm::Error::RuntimeError("Failed to serialize JSON".to_string()))?;
+
+        let resp = client
+            .request(
+                reqwest::Method::POST,
+                self.url.join("/embed").map_err(|_| {
+                    wasi_llm::Error::RuntimeError("Failed to create URL".to_string())
+                })?,
+            )
+            .headers(headers)
+            .body(body)
+            .send()
+            .await
+            .map_err(|err| {
+                wasi_llm::Error::RuntimeError(format!("POST /embed request error: {err}"))
+            })?;
+
+        match resp.json::<EmbeddingResponseBody>().await {
+            Ok(val) => Ok(val.into()),
+            Err(err) => Err(wasi_llm::Error::RuntimeError(format!(
+                "Failed to deserialize response  for \"POST  /embed\": {err}"
+            ))),
+        }
+    }
+
+    fn url(&self) -> Url {
+        self.url.clone()
+    }
+}