n8n 2.31.5 - Fixes AWS Request Signing by Coercing Header Values to Strings

n8n 2.31.5 delivers a critical interoperability fix: the core now coerces AWS request header values to strings prior to signing. AWS request signing (SigV4) is strict about canonicalization and header formats; when header values are non-string types - for example numeric or boolean representations introduced by upstream nodes - signatures can mismatch and calls fail. This change ensures consistent signing input and reduces authentication errors against AWS APIs.

The impact on businesses is tangible: many teams rely on n8n to orchestrate cloud-native workflows that interact with S3, Lambda, SQS and other AWS services. Signature errors are often intermittent and hard to triage because they surface as authorization failures rather than clear type mismatches. By coercing header values to strings, n8n reduces a common class of integration failures, improving reliability for production automations and reducing support overhead.

Leaders should prioritize this patch if you have AWS-dependent workflows. Steps: upgrade to 2.31.5 in a controlled environment, run replay tests for workflows that call AWS APIs, and validate both normal and edge-case payloads. Update integration tests to include non-string header scenarios so future regressions are caught earlier. If you use typed data in upstream nodes, review whether explicit casting to string is appropriate or if centralizing header construction in a helper node yields more consistent behavior.

Finally, incorporate this lesson into integration governance: add signed request validation to CI pipelines and ensure observability captures header shapes for failed calls. Doing so will shorten mean time to resolution for cloud API auth issues and increase confidence in automated cloud operations.