Fix guide
How to fix Polygon RPC 429 errors
A 429 usually means the request pattern and the endpoint capacity no longer match cleanly. It is often an infrastructure fit problem before it is an application design failure.
Guide navigation
What causes repeated 429s
- Bursty request patterns that exceed what a shared endpoint tolerates, even if the average request rate looks reasonable.
- Shared contention where other tenants change behavior on the endpoint before you see a clean limit message.
- Polling loops, backfills, or retries that stack on top of each other and turn a manageable workload into a spike.
- Provider-side envelopes that are harder to reason about because they are expressed through shared behavior instead of clear plan limits.
What people misdiagnose
Teams often assume their code is broken, their retry logic is wrong, or their provider is just having a weird day. The more common reality is that the workflow has become sensitive enough that shared capacity is no longer a stable match.
That is why 429 problems feel random. The average load looks normal, but the burst profile and contention windows are doing the actual damage.
What to check next
- Log status codes, timestamps, and method names so you can see whether 429s cluster around a specific workflow instead of assuming they are random.
- Compare burst size and concurrency, not just average RPS. Most teams underestimate how spiky their workload actually is.
- Check whether retries are amplifying the problem by firing again during the same high-pressure window.
- Run the same request sequence against a dedicated endpoint before rewriting large parts of the application around a shared-RPC bottleneck.
Shared RPC is often still enough when:
- you are learning or testing
- request volume is low and not bursty
- occasional 429s do not harm the workflow
- you can back off without causing downstream damage
Dedicated access becomes justified when:
- 429s repeatedly interrupt real usage
- bots or apps cannot tolerate burst-window failures
- debugging time grows because the endpoint behavior is unclear
- you need transparent request limits instead of shared uncertainty