[github-actions]

agentgateway/agentgateway#4200 — feat(mcp): make the ui:// URI target delimiter configurable

Docs versions: standalone/main, kubernetes/main

What changes for users: Operators can set AGENTGATEWAY_MCP_UI_URI_DELIMITER when an MCP host rejects the default + separator in multiplexed ui:// resource URIs. Valid replacement delimiters are _, -, ., and ~; invalid values log a warning and keep the default +.

What the docs now say: The shared MCP Apps page now explains the delimiter environment variable, the default behavior, the allowed replacement values, and the requirement to choose a delimiter that does not appear in target names.

Not verified: No cluster; the configuration is unrun, and internal links are unchecked.

How agentgateway-4200 was drafted, and what was not verified

• Code PR: feat(mcp): make the ui:// URI target delimiter configurable agentgateway#4200
• Code issue: none linked
• Product: agentgateway (upstream) → agentgateway/website
• Docs version: standalone/main and kubernetes/main
• Category: new-feature / pr

Plan, and what changed it

• Planned: Add the AGENTGATEWAY_MCP_UI_URI_DELIMITER behavior to the MCP Apps documentation for both affected modes.
• Did: Added a gated URI delimiter bullet to the shared MCP Apps asset and wrote a feature release note.

Why a documentation change is necessary

The pull request makes the delimiter in multiplexed ui://{target}+{rest} resource URIs configurable with AGENTGATEWAY_MCP_UI_URI_DELIMITER. The MCP Apps page already documents how agentgateway rewrites UI resource URIs during multiplexing, but it did not tell readers how to handle hosts such as GitHub Copilot that reject the default + delimiter.

What changed on disk

• assets/agw-docs/pages/agentgateway/mcp/apps.md: Adds main-only documentation for AGENTGATEWAY_MCP_UI_URI_DELIMITER, including valid values, fallback behavior, and target-name guidance.

How to verify this change

1. Run an existing MCP Apps multiplexing scenario with AGENTGATEWAY_MCP_UI_URI_DELIMITER=_ set before the proxy starts.
2. Fetch a UI resource URI through the MCP client or test harness that scenario uses.
3. The client-visible URI uses the form ui://<target>_<rest>. If the delimiter value is empty, more than one character, or not one of the allowed symbols, the proxy logs a warning and uses +.

What was not verified

• No cluster was configured for this CI run, so the configuration is unrun.
• No standalone proxy run was available; the delimiter behavior was read from the code diff, not executed.
• Internal links are unchecked because this run did not run Hugo.

How the pages were chosen (triage report)

New configuration: no page mentions it yet

agentgateway/agentgateway#4200 — feat(mcp): make the ui:// URI target delimiter configurable

• Product: agentgateway (upstream) → agentgateway/website
• Docs version: standalone/main, kubernetes/main
• Summary (read from the body): - Making the + in encode_ui_uri configurable - The default is still a + so its backward compatible
• Not tested: no cluster was available, so every command in this diff is unrun

Release notes

This pull request also adds its release-note entries:

• content/docs/kubernetes/main/release-notes/release-notes.md: MCP Apps UI URI delimiter is configurable (feature, in a new 1.8 section)
• content/docs/standalone/main/release-notes/release-notes.md: MCP Apps UI URI delimiter is configurable (feature, in a new 1.8 section)

Check these release-note links and names. Each note is on its page, but a link may not reach the drafted content there, or a name may belong to the other mode:

• content/docs/standalone/main/release-notes/release-notes.md: feat(mcp): make the ui:// URI target delimiter configurable agentgateway#4200's note names AGENTGATEWAY_MCP_UI_URI_DELIMITER, which content/docs/kubernetes/main mentions and content/docs/standalone/main does not. Check that this tree's readers can set it, or word the note for this mode.
• content/docs/standalone/main/release-notes/release-notes.md: feat(mcp): make the ui:// URI target delimiter configurable agentgateway#4200's note names between the target name and UI resource path when an MCP host rejects the default, which content/docs/kubernetes/main mentions and content/docs/standalone/main does not. Check that this tree's readers can set it, or word the note for this mode.

Draft branch: pr-tracker-draft-agentgateway-4200

[cloudflare-workers-and-pages]

Deploying agentproxy with    Cloudflare Pages

Latest commit:	021b36f
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View logs

[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.