diff --git a/lib/agentic/llm_client.rb b/lib/agentic/llm_client.rb
index ae7d4dc..8a6581b 100644
--- a/lib/agentic/llm_client.rb
+++ b/lib/agentic/llm_client.rb
@@ -161,7 +161,10 @@ def without_retry(messages, parameters, output_schema, fail_on_error, stream_cal
         content = @last_response.dig("choices", 0, "message", "content")
         LlmResponse.success(@last_response, content)
       end
-    rescue OpenAI::Error => e
+    rescue OpenAI::Error, Faraday::Error => e
+      # ruby-openai 8.x re-raises Faraday::Error for HTTP failures (429/401/5xx/timeouts)
+      # rather than wrapping them in OpenAI::Error, so both must be mapped here or
+      # they fall through to the generic LlmError and RetryHandler never retries.
       error = map_openai_error(e)
       Agentic.logger.error("OpenAI API error: #{error.message}")
       handle_error(error, fail_on_error)
@@ -288,6 +291,27 @@ def map_openai_error(error)
           "OpenAI API connection error: #{error.message}",
           network_exception: error
         )
+      when defined?(Faraday::Error) && Faraday::Error
+        status = error.respond_to?(:response_status) ? error.response_status : nil
+        headers = error.respond_to?(:response_headers) ? (error.response_headers || {}) : {}
+        response = (error.respond_to?(:response) && error.response.is_a?(Hash)) ? error.response : nil
+
+        case status
+        when 429
+          Errors::LlmRateLimitError.new(
+            "OpenAI API rate limit exceeded: #{error.message}",
+            retry_after: headers["retry-after"]&.to_i,
+            response: response
+          )
+        when 401, 403
+          Errors::LlmAuthenticationError.new("OpenAI API authentication error: #{error.message}", response: response)
+        when 400, 404, 422
+          Errors::LlmInvalidRequestError.new("Invalid request to OpenAI API: #{error.message}", response: response)
+        when 500..599
+          Errors::LlmServerError.new("OpenAI API server error: #{error.message}", response: response)
+        else
+          Errors::LlmNetworkError.new("OpenAI API connection error: #{error.message}", network_exception: error)
+        end
       when OpenAI::Error
         # Parse error message to determine specific error type
         message = error.message.to_s.downcase
diff --git a/spec/agentic/llm_client_spec.rb b/spec/agentic/llm_client_spec.rb
index 2871d26..f0bb11b 100644
--- a/spec/agentic/llm_client_spec.rb
+++ b/spec/agentic/llm_client_spec.rb
@@ -279,6 +279,36 @@
         end
       end
 
+      context "when the HTTP layer raises Faraday::TooManyRequestsError (ruby-openai 8.x)" do
+        let(:faraday_429) do
+          Faraday::TooManyRequestsError.new(nil, {status: 429, headers: {"retry-after" => "1"}, body: "rate limited"})
+        end
+
+        it "maps to LlmRateLimitError rather than a generic LlmError" do
+          allow(openai_client).to receive(:chat).and_raise(faraday_429)
+
+          result = subject.complete(messages, use_retries: false)
+
+          expect(result.success?).to be false
+          expect(result.error).to be_a(Agentic::Errors::LlmRateLimitError)
+          expect(result.error.retry_after).to eq(1)
+        end
+
+        it "is retried by RetryHandler and succeeds on the next attempt" do
+          calls = 0
+          allow(openai_client).to receive(:chat) do
+            calls += 1
+            raise faraday_429 if calls == 1
+            success_response
+          end
+
+          result = subject.complete(messages, fail_on_error: true)
+
+          expect(result.success?).to be true
+          expect(calls).to eq(2)
+        end
+      end
+
       context "when rate limit error occurs" do
         before do
           allow(openai_client).to receive(:chat).and_raise(rate_limit_error)
@@ -488,6 +518,47 @@
     end
 
     describe "#map_openai_error" do
+      context "with Faraday errors re-raised by ruby-openai 8.x" do
+        def faraday_error(klass, status, headers: {}, body: nil)
+          klass.new(nil, {status: status, headers: headers, body: body})
+        end
+
+        it "maps 429 to LlmRateLimitError with retry-after" do
+          error = faraday_error(Faraday::TooManyRequestsError, 429, headers: {"retry-after" => "7"}, body: "slow down")
+          mapped = subject.send(:map_openai_error, error)
+          expect(mapped).to be_a(Agentic::Errors::LlmRateLimitError)
+          expect(mapped.retry_after).to eq(7)
+        end
+
+        it "maps 401 and 403 to LlmAuthenticationError" do
+          expect(subject.send(:map_openai_error, faraday_error(Faraday::UnauthorizedError, 401)))
+            .to be_a(Agentic::Errors::LlmAuthenticationError)
+          expect(subject.send(:map_openai_error, faraday_error(Faraday::ForbiddenError, 403)))
+            .to be_a(Agentic::Errors::LlmAuthenticationError)
+        end
+
+        it "maps 400, 404 and 422 to LlmInvalidRequestError" do
+          [[Faraday::BadRequestError, 400], [Faraday::ResourceNotFound, 404], [Faraday::UnprocessableEntityError, 422]].each do |klass, status|
+            expect(subject.send(:map_openai_error, faraday_error(klass, status)))
+              .to be_a(Agentic::Errors::LlmInvalidRequestError)
+          end
+        end
+
+        it "maps 5xx to LlmServerError" do
+          mapped = subject.send(:map_openai_error, faraday_error(Faraday::ServerError, 503, body: "upstream down"))
+          expect(mapped).to be_a(Agentic::Errors::LlmServerError)
+        end
+
+        it "maps a Faraday::Error with no HTTP status to LlmNetworkError" do
+          mapped = subject.send(:map_openai_error, Faraday::Error.new("socket reset"))
+          expect(mapped).to be_a(Agentic::Errors::LlmNetworkError)
+        end
+
+        it "still maps Faraday::TimeoutError to LlmTimeoutError" do
+          mapped = subject.send(:map_openai_error, Faraday::TimeoutError.new("execution expired"))
+          expect(mapped).to be_a(Agentic::Errors::LlmTimeoutError)
+        end
+      end
       context "with different OpenAI error types" do
         let(:timeout_error) { OpenAI::Timeout.new("Request timeout") }
         let(:rate_limit_error) { OpenAI::RateLimitError.new("Rate limit") }