1 files changed, 28 insertions, 0 deletions
diff --git a/rag/retriever/rerank/cohere.py b/rag/retriever/rerank/cohere.py
new file mode 100644
index 0000000..dac9ab5
--- /dev/null
+++ b/rag/retriever/rerank/cohere.py
@@ -0,0 +1,28 @@
+import os
+
+import cohere
+from loguru import logger as log
+
+from rag.generator.prompt import Prompt
+from rag.retriever.rerank.abstract import AbstractReranker
+
+
+class CohereReranker(metaclass=AbstractReranker):
+    def __init__(self) -> None:
+        self.client = cohere.Client(os.environ["COHERE_API_KEY"])
+        self.top_k = int(os.environ["RERANK_TOP_K"])
+
+    def rank(self, prompt: Prompt) -> Prompt:
+        if prompt.documents:
+            response = self.client.rerank(
+                model="rerank-english-v3.0",
+                query=prompt.query,
+                documents=[d.text for d in prompt.documents],
+                top_n=self.top_k,
+            )
+            ranking = list(filter(lambda x: x.relevance_score > 0.5, response.results))
+            log.debug(
+                f"Reranking gave {len(ranking)} relevant documents of {len(prompt.documents)}"
+            )
+            prompt.documents = [prompt.documents[r.index] for r in ranking]
+        return prompt