9router
A routing layer that keeps your coding agent alive when one provider rate-limits you — worth it for the fallback alone.
9router sits between your agent and forty-odd model providers, doing automatic fallback when one endpoint hits a limit, plus token trimming on the way out. The honest framing: this is an availability and cost play, not a quality play. You get resilience against rate limits and a smaller token bill; you do not get a smarter agent. Also read the license and terms before pointing it at a corporate codebase — routing your prompts through an aggregator is a data-residency decision, not just a config change.
Best for: Individuals and small teams hitting provider rate limits during heavy agent sessions
What to do about it
- Improves availability
- Reduces costs
- Check license terms
What it is
9router is a routing layer that sits between an agent and multiple model providers. It automatically switches to another provider when one hits a rate limit. It also trims tokens on outgoing requests.
This tool is designed to improve availability and reduce costs. It helps keep the agent running when a provider rate-limits it. The goal is to provide resilience against rate limits and lower token bills.
Where it fits in a deployment stack
In a production system, a routing layer like 9router normally sits between the agent and the model providers. Its job is to manage the flow of requests and responses. This helps ensure the system keeps running smoothly even when a provider is unavailable.
A routing layer can help reduce the complexity of managing multiple providers. It can also help improve the overall reliability of the system. By automatically switching between providers, it can help minimize downtime and reduce the impact of rate limits.
How to evaluate it
To evaluate 9router, you need to test its performance and behavior in different scenarios. This includes measuring its latency, throughput, and error rates. You should also test its ability to switch between providers and handle rate limits.
- Measure p95 latency of the retrieval step under 50 concurrent sessions
- Inject a rate limit error from a provider and verify the fallback behavior
- Inspect the token trimming output for a sample set of requests
- Measure the throughput of the routing layer under varying loads
- Test the error handling behavior for different types of provider errors
- Verify the consistency of responses from different providers
What to verify before you commit
Before committing to 9router, you need to verify several key aspects of the tool. This includes its license and terms, data handling and residency, operational costs, failure behavior, and potential lock-in.
- Check the license terms for any restrictions on use in a corporate codebase
- Verify how 9router handles data residency and privacy
- Estimate the operational costs of using 9router, including any additional fees
- Test the failure behavior of 9router in different scenarios, including provider outages
- Check for any potential lock-in, including dependence on specific providers or formats
- Review the documentation and support resources for 9router
Where this fits in the FDE path
- FDE career path — the levels, the titles that map to them, and what changes at each step
- Interview guide — what the loop tests beyond coding
- Pay data — 223 postings — midpoint median $231,000, employer-published ranges only
- 922 live FDE roles — pulled daily from employers’ own job boards