From 24381263baada442c6367c9a78a9b8288b9daed6 Mon Sep 17 00:00:00 2001
From: Josh Brito <65372461+Jbrito6492@users.noreply.github.com>
Date: Sat, 6 Jul 2024 19:52:46 -0700
Subject: [PATCH] Issue 697 - Show API error when calling `.complete` on
 Anthropic client (#698)

---
 lib/langchain/llm/anthropic.rb         | 14 +++++++++++++-
 lib/langchain/llm/base.rb              |  1 +
 spec/fixtures/llm/anthropic/error.json |  7 +++++++
 spec/langchain/llm/anthropic_spec.rb   | 19 +++++++++++++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 spec/fixtures/llm/anthropic/error.json

diff --git a/lib/langchain/llm/anthropic.rb b/lib/langchain/llm/anthropic.rb
index 502f0899d..aa282d952 100644
--- a/lib/langchain/llm/anthropic.rb
+++ b/lib/langchain/llm/anthropic.rb
@@ -81,7 +81,10 @@ def complete(
       parameters[:metadata] = metadata if metadata
       parameters[:stream] = stream if stream
 
-      response = client.complete(parameters: parameters)
+      response = with_api_error_handling do
+        client.complete(parameters: parameters)
+      end
+
       Langchain::LLM::AnthropicResponse.new(response)
     end
 
@@ -114,6 +117,15 @@ def chat(params = {})
       Langchain::LLM::AnthropicResponse.new(response)
     end
 
+    def with_api_error_handling
+      response = yield
+      return if response.empty?
+
+      raise Langchain::LLM::ApiError.new "Anthropic API error: #{response.dig("error", "message")}" if response&.dig("error")
+
+      response
+    end
+
     private
 
     def set_extra_headers!
diff --git a/lib/langchain/llm/base.rb b/lib/langchain/llm/base.rb
index 2f58752d4..73410ec26 100644
--- a/lib/langchain/llm/base.rb
+++ b/lib/langchain/llm/base.rb
@@ -8,6 +8,7 @@ class ApiError < StandardError; end
   # Langchain.rb provides a common interface to interact with all supported LLMs:
   #
   # - {Langchain::LLM::AI21}
+  # - {Langchain::LLM::Anthropic}
   # - {Langchain::LLM::Azure}
   # - {Langchain::LLM::Cohere}
   # - {Langchain::LLM::GooglePalm}
diff --git a/spec/fixtures/llm/anthropic/error.json b/spec/fixtures/llm/anthropic/error.json
new file mode 100644
index 000000000..4051eea03
--- /dev/null
+++ b/spec/fixtures/llm/anthropic/error.json
@@ -0,0 +1,7 @@
+{
+  "type": "error",
+  "error": {
+    "type": "invalid_request_error",
+    "message": "The request is invalid. Please check the request and try again."
+  }
+}
diff --git a/spec/langchain/llm/anthropic_spec.rb b/spec/langchain/llm/anthropic_spec.rb
index 9cc140fbb..f7bbf2831 100644
--- a/spec/langchain/llm/anthropic_spec.rb
+++ b/spec/langchain/llm/anthropic_spec.rb
@@ -30,6 +30,25 @@
         expect(subject.complete(prompt: completion).model).to eq("claude-2.1")
       end
     end
+
+    context "with failed API call" do
+      let(:fixture) { File.read("spec/fixtures/llm/anthropic/error.json") }
+
+      before do
+        allow(subject.client).to receive(:complete)
+          .with(parameters: {
+            model: described_class::DEFAULTS[:completion_model_name],
+            prompt: completion,
+            temperature: described_class::DEFAULTS[:temperature],
+            max_tokens_to_sample: described_class::DEFAULTS[:max_tokens_to_sample]
+          })
+          .and_return(JSON.parse(fixture))
+      end
+
+      it "raises an error" do
+        expect { subject.complete(prompt: completion) }.to raise_error(Langchain::LLM::ApiError, "Anthropic API error: The request is invalid. Please check the request and try again.")
+      end
+    end
   end
 
   describe "#chat" do