From d11255a74cd4d0a9916a77ab34b58f20462ec1af Mon Sep 17 00:00:00 2001
From: Copilot <223556219+Copilot@users.noreply.github.com>
Date: Mon, 23 Mar 2026 14:17:09 +0000
Subject: [PATCH] feat: add ::session.handoff-data spec with :host field
 (upstream PR #900)

- Add ::remote-session-id spec (string)
- Add ::session.handoff-data spec documenting optional :remote-session-id
  and :host fields (GitHub host URL for source session)
- Update API.md to document session.handoff event data fields
- Update CHANGELOG.md under [Unreleased]

The :host field passes through automatically from wire format since
util/wire->clj translates JSON keys to Clojure keywords.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 CHANGELOG.md                     | 2 ++
 doc/reference/API.md             | 2 +-
 src/github/copilot_sdk/specs.clj | 5 +++++
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a056149..312be4d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 All notable changes to this project will be documented in this file. This change log follows the conventions of [keepachangelog.com](http://keepachangelog.com/).
 
 ## [Unreleased]
+### Added (v0.2.0 sync)
+- **`:host` field on `session.handoff` events** — `session.handoff` event data now includes an optional `:host` field with the GitHub host URL for the source session (e.g., `"https://github.com"` or `"https://tenant.ghe.com"`). New `::session.handoff-data` spec documents the shape: `{:remote-session-id "..." :host "..."}` (both optional) (upstream PR #900).
 
 ## [0.2.0.0] - 2026-03-23
 ### Added (v0.2.0 sync)
diff --git a/doc/reference/API.md b/doc/reference/API.md
index bc5ae16..6c0d148 100644
--- a/doc/reference/API.md
+++ b/doc/reference/API.md
@@ -993,7 +993,7 @@ Convert an unqualified event keyword to a namespace-qualified `:copilot/` keywor
 | `:copilot/session.idle` | Session finished processing |
 | `:copilot/session.info` | Informational session update |
 | `:copilot/session.model_change` | Session model changed |
-| `:copilot/session.handoff` | Session handed off to another agent |
+| `:copilot/session.handoff` | Session handed off to another agent; data: `{:remote-session-id "..." :host "https://github.com"}` (both optional) |
 | `:copilot/session.usage_info` | Token usage information |
 | `:copilot/session.context_changed` | Session context (cwd, repo, branch) changed |
 | `:copilot/session.title_changed` | Session title updated |
diff --git a/src/github/copilot_sdk/specs.clj b/src/github/copilot_sdk/specs.clj
index c6fdb09..de3bd33 100644
--- a/src/github/copilot_sdk/specs.clj
+++ b/src/github/copilot_sdk/specs.clj
@@ -540,6 +540,11 @@
 
 (s/def ::session.idle-data map?)
 
+(s/def ::remote-session-id string?)
+
+(s/def ::session.handoff-data
+  (s/keys :opt-un [::remote-session-id ::host]))
+
 (s/def ::agent-mode #{:interactive :plan :autopilot :shell})
 (s/def ::interaction-id string?)