Diagnostic headers

For each request, Edge Gateway exposes several X- headers that help track URL processing and diagnose issues.

Request headers

Headers you send to Edge Gateway.

X-Render-Key

Authentication token for host authorization.

Property	Value
Required	Yes
Value	Render key from host configuration

X-Request-ID

Custom request ID for distributed tracing.

Property	Value
Required	No
Default	Auto-generated UUID
Max length	36 characters

If provided, Edge Gateway sanitizes and uses this ID for request tracking throughout the system. If absent, a UUID is generated automatically.

Providing a custom request ID allows you to easily debug request processing in high traffic environments.

Response headers

Headers Edge Gateway returns in every response.

X-Request-ID

Request tracing identifier. Always present in responses.

Returns either your custom ID (with a 5-character random prefix) or the auto-generated UUID.

X-Render-Source

Indicates the source of the served content.

Value	Description
rendered	Freshly rendered by Chrome
cache	Served from render cache
bypass	Direct fetch from origin (no rendering)
bypass_cache	Served from bypass cache

X-Render-Cache

Cache operation status.

Value	Description
new	Freshly rendered content (not from cache)
hit	Cache found and valid
stale	Cache expired but served within stale TTL
bypass	Cache was bypassed

X-Render-Service

Render service instance that processed the request.

Only present when X-Render-Source: rendered.

X-Cache-Age

Time in seconds since content was cached.

Only present when serving from cache (X-Render-Source: cache or bypass_cache).

X-Matched-Rule

ID of the URL pattern rule that matched the request.

Only present when the request matched a configured URL rule with an ID.

X-Unmatched-Dimension

Set to true when the User-Agent didn't match any configured dimension and a fallback was applied.

Only present when fallback behavior is triggered.

X-Render-Action

Set to status when a status action (3xx, 4xx, 5xx) was performed.

Only present for status action responses.

X-Processed-URL

Normalized URL after tracking parameter stripping.

Only present when tracking parameter removal is enabled and parameters were stripped.

Troubleshooting with headers

Use these headers to diagnose issues without accessing logs.

Verify content source

Check X-Render-Source to confirm whether content came from cache or was freshly rendered:

curl -I -H "X-Render-Key: your-key" https://edge.example.com/page

Check cache freshness

Combine X-Render-Cache and X-Cache-Age to understand cache state:

• X-Render-Cache: hit with low X-Cache-Age = fresh cache
• X-Render-Cache: stale = expired but within stale TTL
• X-Render-Cache: new = cache miss, freshly rendered

Trace requests

Use X-Request-ID to correlate logs across Edge Gateway and Render Service:

curl -H "X-Render-Key: your-key" \
     -H "X-Request-ID: my-trace-123" \
     https://edge.example.com/page

Identify matched rules

Check X-Matched-Rule to verify which URL pattern configuration applied to the request.

Debug dimension matching

If X-Unmatched-Dimension: true appears, the User-Agent didn't match any configured dimension. Review your dimension patterns or check that the correct User-Agent was sent.

Internal headers

Headers used internally between services. Not typically relevant for client integration.

X-Edge-Render

Added by Render Service to all outgoing Chrome requests. Used to prevent rendering loops when nginx is configured to route crawler traffic to Edge Gateway.

Property	Value
Set by	Render Service
Value	Render Service ID (e.g., rs-1)
Purpose	Loop prevention

When nginx detects this header, it should skip crawler routing and forward the request directly to origin. See nginx integration for configuration details.

X-Internal-Auth

Authentication header for internal API endpoints between Edge Gateway instances and Cache Daemon.

Property	Value
Required	Yes (for internal APIs)
Value	cache_sharding.internal_auth_key from config

Used by Edge Gateway-to-Edge Gateway communication (cache pull/push/status) and Cache Daemon-to-Edge Gateway communication (recache).