I’m building AI agents with LangGraph. They call OpenRouter, Anthropic, OpenAI constantly.
The problem: Step 7 of a workflow hits a 429. Everything dies. Start over from step 1.
Or worse: OpenRouter US-East isn’t DOWN, just slow (10s instead of 2s). DNS keeps routing me there. Workflow hangs for 60 seconds, then times out.
I got tired of restarting workflows and debugging “why is it slow for some requests but not others.”
So I built a coordination layer on Fly.io that:
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Automatically reroutes around 429s and slow regions
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Resumes workflows via webhooks (no progress lost)
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Coordinates retries across distributed workers (no retry storms)
Why this only works on Fly.io:
On AWS, multi-region API coordination requires:
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DynamoDB global tables
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VPC peering across regions
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Redis for distributed locks
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$5k-10k/month infrastructure
On Fly.io:
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Anycast routing (one IP, routes to nearest healthy region automatically)
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WireGuard private network (fast cross-region coordination)
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BEAM processes coordinating via Syn
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$50-200/month
The architecture:
BEAM actor per URL. Each actor maintains its own queue, rate limits, and regional health tracking. Millions of lightweight processes coordinating via message passing. No shared state, no locks, no race conditions.
Telephony-grade reliability for HTTP requests.
If you’re building LangGraph agents and hitting reliability problems:
Article with code examples: https://www.ezthrottle.network/blog/stop-losing-langgraph-progress
Architecture deep dive: https://www.ezthrottle.network/blog/making-failure-boring-again
Happy to answer questions about the architecture or how Fly’s network makes this possible.