OpenRouter + Aider Multi-Model Orchestration

Problem

Building AI orchestrators that use multiple models via OpenRouter with Aider involves several non-obvious integration challenges: model naming, API key routing, handling large inputs, and parsing structured output.

Context / Trigger Conditions

• Error: "No endpoints found for anthropic/claude-3-opus" - deprecated model name
• Error: "Missing Anthropic API Key" - missing openrouter/ prefix
• Error: "Argument list too long" - file content too large for command line
• Error: "Invalid control character" in JSON - Aider wraps lines at ~80 chars
• Error: "untracked working tree files would be overwritten" for .aider.* - merge conflict
• Building multi-agent systems with cost-aware model routing

Solution