> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt
> Use this file to discover all available pages before exploring further.

# Tracer CORS and service-discovery configuration

> Tracer documentation now correctly describes its CORS default and enabled service-discovery requirements.

<Badge stroke icon="calendar-days" iconType="regular">September 2, 2026</Badge> <Badge stroke icon="file-code" iconType="regular">Documentation correction</Badge> <Badge color="purple" size="lg" stroke icon="eye" iconType="regular">Review recommended</Badge>

## Affects

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Teams deploying Tracer behind a browser client or with Consul service discovery enabled.

## What changed

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The documentation now correctly states that an unset or empty `CORS_ALLOWED_ORIGINS` value blocks cross-origin requests. Configure an explicit allow-list when browser clients need cross-origin access.

Service discovery is active when `SD_ENABLED=true`. Tracer registers as `midaz-tracer`, resolves Access Manager through Consul, and falls back to `PLUGIN_AUTH_ADDRESS` if that resolution fails. Enabling discovery requires either `SD_EXTERNAL_ADDRESS` or `SD_INTERNAL_ADDRESS`.

## Impact

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**Classification: Review recommended.** This is a correction to the documented configuration contract; it does not announce a runtime change.

## What you need to do

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Review browser deployments that rely on an empty CORS setting and discovery-enabled deployments that do not declare an advertised address.