Anthropic Advanced Troubleshooting

Issue: Context Window Overflow

# Symptom: invalid_request_error about token count
# Diagnosis: pre-check with Token Counting API
import anthropic

client = anthropic.Anthropic()

count = client.messages.count_tokens(
    model="claude-sonnet-4-20250514",
    messages=conversation_history,
    system=system_prompt
)
print(f"Input tokens: {count.input_tokens}")
# Claude Sonnet: 200K context, Claude Opus: 200K context