fix(coding-agent): reuse session thinking for compaction closes #3438

packages/coding-agent/CHANGELOG.md

@@ -9,6 +9,7 @@
 ### Fixed
 
 - Fixed missing `@sinclair/typebox` runtime dependency in `@mariozechner/pi-coding-agent`, so strict pnpm installs no longer fail with `ERR_MODULE_NOT_FOUND` when starting `pi` ([#3434](https://github.com/badlogic/pi-mono/issues/3434))
+- Fixed `/compact` to reuse the session thinking level for compaction summaries instead of forcing `high`, avoiding invalid reasoning-effort errors on `github-copilot/claude-opus-4.7` sessions configured for `medium` thinking ([#3438](https://github.com/badlogic/pi-mono/issues/3438))
 - Fixed shared/exported plain-text tool output to preserve indentation instead of collapsing leading whitespace in the web share page ([#3440](https://github.com/badlogic/pi-mono/issues/3440))
 - Fixed skill resolution to dedupe symlinked aliases by canonical path, so `pi config` no longer shows duplicate skill entries when `~/.pi/agent/skills` points to `~/.agents/skills` ([#3405](https://github.com/badlogic/pi-mono/issues/3405))
 - Fixed OpenRouter request attribution to include Pi app headers (`HTTP-Referer: https://pi.dev`, `X-OpenRouter-Title: pi`, `X-OpenRouter-Categories: cli-agent`) when sessions are created through the coding-agent SDK and install telemetry is enabled ([#3414](https://github.com/badlogic/pi-mono/issues/3414))

packages/coding-agent/src/core/agent-session.ts

@@ -1667,6 +1667,7 @@ export class AgentSession {
 					headers,
 					customInstructions,
 					this._compactionAbortController.signal,
+					this.thinkingLevel,
 				);
 				summary = result.summary;
 				firstKeptEntryId = result.firstKeptEntryId;
@@ -1931,6 +1932,7 @@ export class AgentSession {
 					headers,
 					undefined,
 					this._autoCompactionAbortController.signal,
+					this.thinkingLevel,
 				);
 				summary = compactResult.summary;
 				firstKeptEntryId = compactResult.firstKeptEntryId;

packages/coding-agent/src/core/compaction/compaction.ts

@@ -5,7 +5,7 @@
  * and after compaction the session is reloaded.
  */
 
-import type { AgentMessage } from "@mariozechner/pi-agent-core";
+import type { AgentMessage, ThinkingLevel } from "@mariozechner/pi-agent-core";
 import type { AssistantMessage, Model, Usage } from "@mariozechner/pi-ai";
 import { completeSimple } from "@mariozechner/pi-ai";
 import {
@@ -536,6 +536,7 @@ export async function generateSummary(
 	signal?: AbortSignal,
 	customInstructions?: string,
 	previousSummary?: string,
+	thinkingLevel?: ThinkingLevel,
 ): Promise<string> {
 	const maxTokens = Math.floor(0.8 * reserveTokens);
 
@@ -565,9 +566,10 @@ export async function generateSummary(
 		},
 	];
 
-	const completionOptions = model.reasoning
+	const completionOptions =
-		? { maxTokens, signal, apiKey, headers, reasoning: "high" as const }
+		model.reasoning && thinkingLevel && thinkingLevel !== "off"
-		: { maxTokens, signal, apiKey, headers };
+			? { maxTokens, signal, apiKey, headers, reasoning: thinkingLevel }
+			: { maxTokens, signal, apiKey, headers };
 
 	const response = await completeSimple(
 		model,
@@ -719,6 +721,7 @@ export async function compact(
 	headers?: Record<string, string>,
 	customInstructions?: string,
 	signal?: AbortSignal,
+	thinkingLevel?: ThinkingLevel,
 ): Promise<CompactionResult> {
 	const {
 		firstKeptEntryId,
@@ -747,9 +750,18 @@ export async function compact(
 						signal,
 						customInstructions,
 						previousSummary,
+						thinkingLevel,
 					)
 				: Promise.resolve("No prior history."),
-			generateTurnPrefixSummary(turnPrefixMessages, model, settings.reserveTokens, apiKey, headers, signal),
+			generateTurnPrefixSummary(
+				turnPrefixMessages,
+				model,
+				settings.reserveTokens,
+				apiKey,
+				headers,
+				signal,
+				thinkingLevel,
+			),
 		]);
 		// Merge into single summary
 		summary = `${historyResult}\n\n---\n\n**Turn Context (split turn):**\n\n${turnPrefixResult}`;
@@ -764,6 +776,7 @@ export async function compact(
 			signal,
 			customInstructions,
 			previousSummary,
+			thinkingLevel,
 		);
 	}
 
@@ -793,6 +806,7 @@ async function generateTurnPrefixSummary(
 	apiKey: string,
 	headers?: Record<string, string>,
 	signal?: AbortSignal,
+	thinkingLevel?: ThinkingLevel,
 ): Promise<string> {
 	const maxTokens = Math.floor(0.5 * reserveTokens); // Smaller budget for turn prefix
 	const llmMessages = convertToLlm(messages);
@@ -809,7 +823,9 @@ async function generateTurnPrefixSummary(
 	const response = await completeSimple(
 		model,
 		{ systemPrompt: SUMMARIZATION_SYSTEM_PROMPT, messages: summarizationMessages },
-		{ maxTokens, signal, apiKey, headers },
+		model.reasoning && thinkingLevel && thinkingLevel !== "off"
+			? { maxTokens, signal, apiKey, headers, reasoning: thinkingLevel }
+			: { maxTokens, signal, apiKey, headers },
 	);
 
 	if (response.stopReason === "error") {

packages/coding-agent/test/compaction-summary-reasoning.test.ts

@@ -56,18 +56,58 @@ describe("generateSummary reasoning options", () => {
 		completeSimpleMock.mockResolvedValue(mockSummaryResponse);
 	});
 
-	it("sets reasoning=high for reasoning-capable models", async () => {
+	it("uses the provided thinking level for reasoning-capable models", async () => {
-		await generateSummary(messages, createModel(true), 2000, "test-key");
+		await generateSummary(
+			messages,
+			createModel(true),
+			2000,
+			"test-key",
+			undefined,
+			undefined,
+			undefined,
+			undefined,
+			"medium",
+		);
 
 		expect(completeSimpleMock).toHaveBeenCalledTimes(1);
 		expect(completeSimpleMock.mock.calls[0][2]).toMatchObject({
-			reasoning: "high",
+			reasoning: "medium",
 			apiKey: "test-key",
 		});
 	});
 
+	it("does not set reasoning when thinking is off", async () => {
+		await generateSummary(
+			messages,
+			createModel(true),
+			2000,
+			"test-key",
+			undefined,
+			undefined,
+			undefined,
+			undefined,
+			"off",
+		);
+
+		expect(completeSimpleMock).toHaveBeenCalledTimes(1);
+		expect(completeSimpleMock.mock.calls[0][2]).toMatchObject({
+			apiKey: "test-key",
+		});
+		expect(completeSimpleMock.mock.calls[0][2]).not.toHaveProperty("reasoning");
+	});
+
 	it("does not set reasoning for non-reasoning models", async () => {
-		await generateSummary(messages, createModel(false), 2000, "test-key");
+		await generateSummary(
+			messages,
+			createModel(false),
+			2000,
+			"test-key",
+			undefined,
+			undefined,
+			undefined,
+			undefined,
+			"medium",
+		);
 
 		expect(completeSimpleMock).toHaveBeenCalledTimes(1);
 		expect(completeSimpleMock.mock.calls[0][2]).toMatchObject({