From 43a5447a806ad379f2f87a3da5699615a2801348 Mon Sep 17 00:00:00 2001
From: Mario Zechner <badlogicgames@gmail.com>
Date: Wed, 24 Dec 2025 12:28:51 +0100
Subject: [PATCH] Add resolveApiKey to before_compact hook event

---
 packages/coding-agent/CHANGELOG.md              | 4 ++++
 packages/coding-agent/docs/hooks.md             | 1 +
 packages/coding-agent/src/core/agent-session.ts | 2 ++
 packages/coding-agent/src/core/hooks/types.ts   | 2 ++
 4 files changed, 9 insertions(+)

diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 330f907c..d7de4402 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Added
+
+- **Compaction hook `resolveApiKey`**: The `before_compact` session event now includes `resolveApiKey` function to resolve API keys for any model (checks settings, OAuth, env vars). Useful for hooks that need to call different models during custom compaction.
+
 ## [0.27.5] - 2025-12-24
 
 ### Added
diff --git a/packages/coding-agent/docs/hooks.md b/packages/coding-agent/docs/hooks.md
index b9e062a6..60316a91 100644
--- a/packages/coding-agent/docs/hooks.md
+++ b/packages/coding-agent/docs/hooks.md
@@ -184,6 +184,7 @@ For `before_compact` events, additional fields are available:
 - `event.tokensBefore`: Current context token count
 - `event.model`: Model to use for summarization
 - `event.apiKey`: API key for the model
+- `event.resolveApiKey`: Function to resolve API key for any model (checks settings, OAuth, env vars)
 - `event.customInstructions`: Optional custom focus for summary (from `/compact` command)
 
 Return `{ compactionEntry }` to provide a custom summary instead of the default. The `compactionEntry` must have: `type: "compaction"`, `timestamp`, `summary`, `firstKeptEntryIndex` (from `cutPoint`), `tokensBefore`.
diff --git a/packages/coding-agent/src/core/agent-session.ts b/packages/coding-agent/src/core/agent-session.ts
index f55435f1..6c394b2d 100644
--- a/packages/coding-agent/src/core/agent-session.ts
+++ b/packages/coding-agent/src/core/agent-session.ts
@@ -772,6 +772,7 @@ export class AgentSession {
 					customInstructions,
 					model: this.model,
 					apiKey,
+					resolveApiKey: this._resolveApiKey,
 				})) as SessionEventResult | undefined;
 
 				if (result?.cancel) {
@@ -922,6 +923,7 @@ export class AgentSession {
 					customInstructions: undefined,
 					model: this.model,
 					apiKey,
+					resolveApiKey: this._resolveApiKey,
 				})) as SessionEventResult | undefined;
 
 				if (hookResult?.cancel) {
diff --git a/packages/coding-agent/src/core/hooks/types.ts b/packages/coding-agent/src/core/hooks/types.ts
index 9f8d7746..2653c26d 100644
--- a/packages/coding-agent/src/core/hooks/types.ts
+++ b/packages/coding-agent/src/core/hooks/types.ts
@@ -135,6 +135,8 @@ export type SessionEvent =
 			customInstructions?: string;
 			model: Model<any>;
 			apiKey: string;
+			/** Resolve API key for any model (checks settings, OAuth, env vars) */
+			resolveApiKey: (model: Model<any>) => Promise<string | undefined>;
 	  })
 	| (SessionEventBase & {
 			reason: "compact";