@varlock/aws-sigv4-plugin

Adds an aws-sigv4 request-signing scheme to the varlock credential proxy.

The agent's AWS SDK signs requests normally, using the placeholder credentials varlock injects into its environment. The proxy parses the region and service out of the inbound credential scope, strips the placeholder signature, and re-signs the request with the real keys at the network boundary. The secret access key never enters the agent's environment, and the agent cannot produce a valid signature itself.

# @plugin(@varlock/aws-sigv4-plugin)
# ---
# @proxy(domain="*.amazonaws.com", transform={
#   scheme="aws-sigv4", keyId=$AWS_ACCESS_KEY_ID,
#   allowedServices=[bedrock, s3],
# })
AWS_SECRET_ACCESS_KEY=somePlugin()

# @sensitive
AWS_ACCESS_KEY_ID=somePlugin()

Not just AWS: the same scheme brokers credentials for any SigV4-authenticated service, including S3-compatible stores (Cloudflare R2, MinIO, Backblaze B2, DigitalOcean Spaces) and DynamoDB-compatible endpoints. Point the rule's domain at the service's endpoint.

See the plugin docs for all options and limitations.