Anthropic Advanced Troubleshooting

Overview

Debug complex Claude integration issues that go beyond basic error handling — inconsistent outputs, tool use failures where Claude calls nonexistent tools, streaming connection drops, max_tokens truncation, and image/vision format problems.

Inconsistent Outputs

Symptom: Same prompt gives different answers each time. Cause: temperature defaults to 1.0 (maximum randomness).

// Fix: Set temperature to 0 for deterministic outputs
const message = await client.messages.create({
  model: 'claude-sonnet-4-20250514',
  max_tokens: 1024,
  temperature: 0, // Deterministic
  messages,
});

Tool Use Failures

Symptom: Claude calls a tool that doesn't exist or sends wrong parameters.

// Always validate tool calls before executing
const toolUse = response.content.find(b => b.type === 'tool_use');
if (toolUse) {
  const validTools = tools.map(t => t.name);
  if (!validTools.includes(toolUse.name)) {
    console.error(`Claude requested unknown tool: ${toolUse.name}`);
    // Send error back as tool_result
    messages.push({ role: 'assistant', content: response.content });
    messages.push({ role: 'user', content: [{
      type: 'tool_result',
      tool_use_id: toolUse.id,
      is_error: true,
      content: `Tool "${toolUse.name}" does not exist. Available: ${validTools.join(', ')}`,
    }]});
  }
}

Streaming Connection Drops

Symptom: Stream stops mid-response without message_stop event.

// Detect incomplete streams
const stream = client.messages.stream({ ... });
let gotStop = false;

for await (const event of stream) {
  if (event.type === 'message_stop') gotStop = true;
  // ... process events
}

if (!gotStop) {
  console.error('Stream ended without message_stop — connection dropped');
  // Retry the request
}

max_tokens Truncation

Symptom: Response cuts off mid-sentence.

const message = await client.messages.create({ ... });

if (message.stop_reason === 'max_tokens') {
  console.warn('Response truncated — increase max_tokens or ask for shorter output');
  // Option 1: Increase max_tokens
  // Option 2: Add "Be concise" to system prompt
  // Option 3: Continue the response with another call
}

Image/Vision Issues

Symptom: Claude says it can't see the image.

• Max image size: 5MB
• Supported: PNG, JPEG, GIF, WebP
• Max 20 images per request
• Base64 encoding must be correct (no data URI prefix in the data field)

// Correct image format
{
  type: 'image',
  source: {
    type: 'base64',
    media_type: 'image/png', // Must match actual format
    data: buffer.toString('base64'), // Raw base64, no "data:image/png;base64," prefix
  },
}

Output

• Inconsistent outputs fixed via temperature control
• Tool use validated against defined tool names before execution
• Streaming connection drops detected and retried
• Truncated responses identified via stop_reason check
• Image format issues resolved (correct media_type, raw base64, size limits)

Error Handling

Examples

See Inconsistent Outputs (temperature fix), Tool Use Failures (validation), Streaming Connection Drops (detection), max_tokens Truncation (stop_reason check), and Image/Vision Issues (correct format) above.

Resources

• Error Types
• Tool Use Guide
• Vision Docs

Next Steps

See clade-debug-bundle for collecting support evidence.

Prerequisites

• Completed clade-common-errors for basic error handling
• Familiarity with Claude API response structure
• Access to application logs with full request/response data

Instructions

Step 1: Review the patterns below

Each section contains production-ready code examples. Copy and adapt them to your use case.

Step 2: Apply to your codebase

Integrate the patterns that match your requirements. Test each change individually.

Step 3: Verify

Run your test suite to confirm the integration works correctly.