[github-actions]

agentgateway/agentgateway#4185 + agentgateway/agentgateway#4188 — LLM passthrough and path-model transformations

Docs versions: standalone/main, kubernetes/main

What changes for users: LLM model transformations now apply when the model is encoded in the provider URL path, such as Bedrock, Vertex, and Gemini requests. A model-level passthrough setting also takes precedence over known endpoint detection, so passthrough stays passthrough on known paths.

What the docs now say: The standalone and Kubernetes model transformation, model resolution, virtual model, and Bedrock provider pages now explain that model transformations can rewrite provider URL paths instead of adding a model field to the request body.

Not verified: The configuration is unrun, and internal links are unchecked.

How agentgateway-4185 was drafted, and what was not verified

• Code PRs: (breaking) llm: fix passthrough to proper override known types agentgateway#4185, llm: apply transformations to path based providers agentgateway#4188
• Product: agentgateway (upstream) → agentgateway/website
• Docs version: standalone/main and kubernetes/main
• Category: scoped-edit / pr

Plan, and what changed it

• Planned: Update the virtual model pages that the code-path targets named.
• Learned: The literal search found stale transformation wording on the standalone Bedrock and transformation pages, and the code diff for #4188 shows the unrouted proxy change that rewrites provider path models.
• Did: Updated the target model pages and the stale transformation and Bedrock provider pages; wrote a breaking-change release-note proposal.

Why a documentation change is necessary

#4188 changes path-based provider handling so that model transformations can rewrite the URL path for Bedrock, Vertex, and Gemini requests. Several pages said transformations applied only to request body fields, or only when the model was in a JSON body, which made the documented behavior too narrow. #4185 restores the meaning of the passthrough field so that model passthrough overrides known endpoint detection; the Bedrock passthrough page said model translation was not supported with passthrough, so that claim needed correction.

What changed on disk

• assets/agw-docs/pages/agentgateway/llm/transformations.md: Adds a main-only Kubernetes note that model transformations can rewrite model IDs in provider URL paths.
• content/docs/kubernetes/main/documentation/llm/models/about.md: Updates model policy and resolution wording for path-model transformations.
• content/docs/kubernetes/main/documentation/llm/models/virtual.md: Updates virtual model and callout transformation wording for URL-path model rewrites.
• content/docs/standalone/main/documentation/configuration/traffic-management/llm.md: Updates standalone model resolution wording for path-model transformations.
• content/docs/standalone/main/documentation/llm/transformations.md: Updates the transformation reference and field rows for provider URL path models.
• content/docs/standalone/main/documentation/llm/virtual-models.md: Updates virtual model callout wording so transformations are not described as JSON-model-only.
• content/docs/standalone/main/integrations/llm/providers/bedrock.md: Corrects the passthrough note to say passthrough: detect can still use model transformations.

How to verify this change

1. Configure a Bedrock model with transformation.model mapping a client model ID to a different Bedrock model ID, and send a request whose model is in the path, such as /model/<client-model>/converse?trace=true.
2. Inspect the upstream request. The path should contain the transformed model ID, keep the original query string, and not add model to the request body.
3. Configure the same model with passthrough: detect, then repeat the request. The request should keep Bedrock passthrough behavior while still rewriting the model path.

What was not verified

• The configuration was not applied to a cluster. cluster-facts.md was used only as an API surface, and nothing was applied.
• No Hugo build was run, so internal links are unchecked.
• No Vale pass ran because the vale binary is not installed in this environment.

Dry run of the added manifests

No added manifest was dry-run against the cluster, so nothing in this draft has been checked by the API server.
The dry run never sees field paths written in prose, standalone configuration, or commands, so those are unverified.

How the pages were chosen (triage report)

Feature clusters

These pull requests document one feature between them:

Cluster	Pull requests	Product	Why grouped
c10	agentgateway/agentgateway#4185, agentgateway/agentgateway#4188	agentgateway	the same author merged both within 24 hours, they change the same source file, and both are drafted into content/docs/standalone/main/documentation/llm/virtual-models.md, so this looks like one change split across pull requests and separate drafts would conflict

Draft a documentation change

agentgateway/agentgateway#4185 — (breaking) llm: fix passthrough to proper override known types

• Product: agentgateway (upstream) → agentgateway/website
• Docs version: standalone/main, kubernetes/main
• Summary (read from the body): The 'passthrough' field was originally introduced (documented/implemented) to mean "always do passthrough". Through arefactoring it accidentally changed (without changing the docs) to mean "how to handle unknown paths".
• Not tested: a cluster was used only to dry-run the YAML manifests the draft added; prose, inline field paths and commands are unrun

agentgateway/agentgateway#4188 — llm: apply transformations to path based providers

• Product: agentgateway (upstream) → agentgateway/website
• Docs version: standalone/main, kubernetes/main
• Summary (read from the body): Alternative to fix(llm): resolve native Bedrock model IDs agentgateway#4117 that supports all path based providers not just bedrock
• Not tested: no cluster was available, so every command in this diff is unrun
• No rule covers 1 touched file(s). The candidate pages below come from the files that DID match a rule, so they may scope this narrower than the change is. Read these before deciding the change is only about the pages listed:
  • crates/agentgateway/src/proxy/httpproxy.rs

Release notes

This pull request also adds its release-note entries:

• content/docs/kubernetes/main/release-notes/release-notes.md: LLM model transformations now apply to path-based provider requests (breaking_change, in a new 1.8 section)
• content/docs/standalone/main/release-notes/release-notes.md: LLM model transformations now apply to path-based provider requests (breaking_change, in a new 1.8 section)

Draft branch: pr-tracker-draft-agentgateway-4185-plus1

[cloudflare-workers-and-pages]

Deploying agentproxy with    Cloudflare Pages

Latest commit:	e9c72af
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[kristin-kronstain-brown]

Moved this PR's release-notes entry to the combined release-notes PR, #1482, so the draft PRs stop conflicting on the release-notes pages. Review or change the entry there.