feat: token and cost details on agents view rows

packages/coding-agent/.changes/res-1258-agents-view-costs.md

@@ -0,0 +1 @@
+- Added token and cost details to agents view rows: input/output tokens plus the session's own cost and its recursive total including all subagents; the message-count detail is gone.

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

@@ -280,7 +280,7 @@ import { type BashOperations, createLocalBashOperations } from "./tools/bash.js"
 import { createAllToolDefinitions } from "./tools/index.js";
 import { IpythonKernelProvisioner } from "./tools/ipython.js";
 import { createToolDefinitionFromAgentTool } from "./tools/tool-definition-wrapper.js";
-import { addAssistantUsage, emptyUsage } from "./usage.js";
+import { addAssistantUsage, emptyUsage, type SessionUsageSummary, sessionUsageSummaryFrom } from "./usage.js";
 import { SERPER_CREDENTIAL_ID, SERPER_ENV_VAR, WEBSEARCH_SKILL_NAME } from "./websearch-credential.js";
 
 export type { GoalState, GoalStatus } from "./goals.js";
@@ -7565,6 +7565,7 @@ export class AgentSession {
 		let firstKeptEntryId: string;
 		let tokensBefore: number;
 		let details: CompactionResult["details"];
+		let usage: CompactionResult["usage"];
 		try {
 			if (this._extensionRunner.hasHandlers("session_before_compact")) {
 				const result = (await this._extensionRunner.emit({
@@ -7586,7 +7587,7 @@ export class AgentSession {
 			}
 
 			if (extensionCompaction) {
-				({ summary, firstKeptEntryId, tokensBefore, details } = extensionCompaction);
+				({ summary, firstKeptEntryId, tokensBefore, details, usage } = extensionCompaction);
 			} else {
 				// Each summary wire call gets its own request ID: split turns send two
 				// different bodies, and one Idempotency-Key must never cover both. A slice
@@ -7615,7 +7616,7 @@ export class AgentSession {
 						throw error;
 					}
 				};
-				({ summary, firstKeptEntryId, tokensBefore, details } = await compact(
+				({ summary, firstKeptEntryId, tokensBefore, details, usage } = await compact(
 					preparation,
 					model,
 					apiKey,
@@ -7647,6 +7648,7 @@ export class AgentSession {
 				details,
 				fromExtension,
 				customInstructions,
+				usage,
 			);
 		} catch (error) {
 			compactionSettled = true;
@@ -11732,6 +11734,7 @@ export class AgentSession {
 
 			let summaryText: string | undefined;
 			let summaryDetails: unknown;
+			let summaryUsage: Usage | undefined;
 			if (options.summarize && entriesToSummarize.length > 0 && !extensionSummary) {
 				const model = this.model!;
 				const { apiKey, headers } = await this._getRequiredRequestAuth(model);
@@ -11752,6 +11755,7 @@ export class AgentSession {
 					throw new Error(result.error);
 				}
 				summaryText = result.summary;
+				summaryUsage = result.usage;
 				summaryDetails = {
 					readFiles: result.readFiles || [],
 					modifiedFiles: result.modifiedFiles || [],
@@ -11787,6 +11791,7 @@ export class AgentSession {
 					summaryText,
 					summaryDetails,
 					fromExtension,
+					summaryUsage,
 				);
 				summaryEntry = this.sessionManager.getEntry(summaryId) as BranchSummaryEntry;
 
@@ -11957,6 +11962,22 @@ export class AgentSession {
 		return (provider, modelId) => this._modelRegistry.find(provider, modelId)?.contextWindow;
 	}
 
+	private _ownUsageMemo?: { count: number; tailId: string | undefined; usage: SessionUsageSummary | undefined };
+
+	// Whole-file own spend, identical to the catalog scan so rows never shift at passivation.
+	getOwnUsageSummary(): SessionUsageSummary | undefined {
+		const entries = this.sessionManager.getEntries();
+		const tailId = entries.at(-1)?.id;
+		const memo = this._ownUsageMemo;
+		if (memo && memo.count === entries.length && memo.tailId === tailId) {
+			return memo.usage;
+		}
+		const { ownUsage } = computeOwnAndTotalUsage(entries, entries);
+		const usage = sessionUsageSummaryFrom(ownUsage);
+		this._ownUsageMemo = { count: entries.length, tailId, usage };
+		return usage;
+	}
+
 	/**
 	 * Build the agent context overview for /context: this session as the root
 	 * plus one node per RLM sub-agent, recursively. Running children are read

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

@@ -6,7 +6,7 @@
  */
 
 import type { AgentMessage } from "@earendil-works/pi-agent-core";
-import type { Model } from "@earendil-works/pi-ai";
+import type { Model, Usage } from "@earendil-works/pi-ai";
 import { completeSimple } from "@earendil-works/pi-ai";
 import {
 	convertToLlm,
@@ -31,6 +31,7 @@ export interface BranchSummaryResult {
 	modifiedFiles?: string[];
 	aborted?: boolean;
 	error?: string;
+	usage?: Usage;
 }
 
 /** Details stored in BranchSummaryEntry.details for file tracking */
@@ -303,5 +304,6 @@ export async function generateBranchSummary(
 		summary: summary || "No summary generated",
 		readFiles,
 		modifiedFiles,
+		usage: response.usage,
 	};
 }

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

@@ -15,6 +15,7 @@ import {
 	createCustomMessage,
 } from "../messages.js";
 import { buildSessionContext, type CompactionEntry, type SessionEntry } from "../session-manager.js";
+import { addAssistantUsage, emptyUsage } from "../usage.js";
 import {
 	computeFileLists,
 	createFileOps,
@@ -30,6 +31,11 @@ export interface CompactionDetails {
 	modifiedFiles: string[];
 }
 
+export interface SummarySlice {
+	summary: string;
+	usage?: Usage;
+}
+
 /**
  * Extract file operations from messages and previous compaction entries.
  */
@@ -98,6 +104,8 @@ export interface CompactionResult<T = unknown> {
 	tokensBefore: number;
 	/** Extension-specific data (e.g., ArtifactIndex, version markers for structured compaction) */
 	details?: T;
+	/** What the summarization call(s) billed; persisted on the compaction entry. */
+	usage?: Usage;
 }
 export const COMPACT_SKILL_NAME = "compact";
 
@@ -515,7 +523,7 @@ export async function generateSummary(
 	customInstructions?: string,
 	previousSummary?: string,
 	thinkingLevel?: ThinkingLevel,
-): Promise<string> {
+): Promise<SummarySlice> {
 	const maxTokens = Math.floor(0.8 * reserveTokens);
 
 	const basePrompt = buildSummarizationPrompt(customInstructions, previousSummary);
@@ -556,7 +564,7 @@ export async function generateSummary(
 		.map((c) => c.text)
 		.join("\n");
 
-	return textContent;
+	return { summary: textContent, usage: response.usage };
 }
 export interface CompactionPreparation {
 	/** UUID of first entry to keep */
@@ -696,6 +704,7 @@ export async function compact(
 		settings,
 	} = preparation;
 	let summary: string;
+	const slices: SummarySlice[] = [];
 
 	if (isSplitTurn && turnPrefixMessages.length > 0) {
 		// Split turns make two wire calls with different bodies; each needs its own identity.
@@ -714,7 +723,7 @@ export async function compact(
 							thinkingLevel,
 						),
 					)
-				: Promise.resolve("No prior history."),
+				: Promise.resolve<SummarySlice>({ summary: "No prior history." }),
 			summaryCall((callHeaders) =>
 				generateTurnPrefixSummary(
 					turnPrefixMessages,
@@ -727,9 +736,10 @@ export async function compact(
 				),
 			),
 		]);
-		summary = `${historyResult}\n\n---\n\n**Turn Context (split turn):**\n\n${turnPrefixResult}`;
+		slices.push(historyResult, turnPrefixResult);
+		summary = `${historyResult.summary}\n\n---\n\n**Turn Context (split turn):**\n\n${turnPrefixResult.summary}`;
 	} else {
-		summary = await summaryCall((callHeaders) =>
+		const result = await summaryCall((callHeaders) =>
 			generateSummary(
 				messagesToSummarize,
 				model,
@@ -742,6 +752,8 @@ export async function compact(
 				thinkingLevel,
 			),
 		);
+		slices.push(result);
+		summary = result.summary;
 	}
 	const { readFiles, modifiedFiles } = computeFileLists(fileOps);
 	summary += formatFileOperations(readFiles, modifiedFiles);
@@ -750,11 +762,18 @@ export async function compact(
 		throw new Error("First kept entry has no UUID - session may need migration");
 	}
 
+	let usage: Usage | undefined;
+	for (const slice of slices) {
+		if (!slice.usage) continue;
+		usage ??= emptyUsage();
+		addAssistantUsage(usage, slice.usage);
+	}
 	return {
 		summary,
 		firstKeptEntryId,
 		tokensBefore,
 		details: { readFiles, modifiedFiles } as CompactionDetails,
+		usage,
 	};
 }
 
@@ -769,7 +788,7 @@ async function generateTurnPrefixSummary(
 	headers?: Record<string, string>,
 	signal?: AbortSignal,
 	thinkingLevel?: ThinkingLevel,
-): Promise<string> {
+): Promise<SummarySlice> {
 	const maxTokens = Math.floor(0.5 * reserveTokens); // Smaller budget for turn prefix
 	const llmMessages = convertToLlm(messages);
 	const conversationText = serializeConversation(llmMessages);
@@ -794,8 +813,11 @@ async function generateTurnPrefixSummary(
 		throw new Error(`Turn prefix summarization failed: ${response.errorMessage || "Unknown error"}`);
 	}
 
-	return response.content
-		.filter((c): c is { type: "text"; text: string } => c.type === "text")
-		.map((c) => c.text)
-		.join("\n");
+	return {
+		summary: response.content
+			.filter((c): c is { type: "text"; text: string } => c.type === "text")
+			.map((c) => c.text)
+			.join("\n"),
+		usage: response.usage,
+	};
 }

packages/coding-agent/src/core/context-tree.ts

@@ -83,6 +83,8 @@ export function computeOwnAndTotalUsage(
 		if (isAssistantEntry(entry)) {
 			branchAssistantIds.add(entry.id);
 			addAssistantUsage(totalUsage, entry.message.usage);
+		} else if ((entry.type === "compaction" || entry.type === "branch_summary") && entry.usage) {
+			addAssistantUsage(totalUsage, entry.usage);
 		}
 	}
 	const ownUsage = cloneUsage(totalUsage);

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

@@ -28,7 +28,14 @@ import {
 	createCompactionSummaryMessage,
 	createCustomMessage,
 } from "./messages.js";
-import { cloneUsage } from "./usage.js";
+import {
+	addAssistantUsage,
+	cloneUsage,
+	emptyUsage,
+	type SessionUsageSummary,
+	sessionUsageSummaryFrom,
+	subtractAssistantUsage,
+} from "./usage.js";
 
 export const CURRENT_SESSION_VERSION = 3;
 const SESSION_LIST_SEARCH_TEXT_MAX_CHARS = 64 * 1024;
@@ -129,6 +136,7 @@ export interface CompactionEntry<T = unknown> extends SessionEntryBase {
 	details?: T;
 	fromHook?: boolean;
 	customInstructions?: string;
+	usage?: Usage;
 }
 
 export interface BranchSummaryEntry<T = unknown> extends SessionEntryBase {
@@ -137,6 +145,7 @@ export interface BranchSummaryEntry<T = unknown> extends SessionEntryBase {
 	summary: string;
 	details?: T;
 	fromHook?: boolean;
+	usage?: Usage;
 }
 
 export interface CustomEntry<T = unknown> extends SessionEntryBase {
@@ -255,6 +264,7 @@ export interface SessionInfo {
 	firstMessage: string;
 	allMessagesText: string;
 	agentStatus?: AgentStatus;
+	usage?: SessionUsageSummary;
 }
 
 export type ReadonlySessionManager = Pick<
@@ -953,6 +963,10 @@ async function scanSessionInfo(filePath: string, stats: Awaited<ReturnType<typeo
 		let state: SessionState | undefined;
 		let agentStatus: AgentStatus | undefined;
 		let lastActivityTime: number | undefined;
+		// Fold attribution aggregates like the loader: either disk representation cancels to the same own spend.
+		const assistantUsageById = new Map<string, Usage>();
+		const attributedChildUsages: Usage[] = [];
+		const summarizationUsages: Usage[] = [];
 
 		for await (const lineBuffer of readLinesAsBuffers(filePath)) {
 			const line = lineBuffer.toString("utf8");
@@ -999,7 +1013,17 @@ async function scanSessionInfo(filePath: string, stats: Awaited<ReturnType<typeo
 			if (entry.type === "agent_status") {
 				agentStatus = (entry as AgentStatusEntry).status;
 			}
-
+			if (entry.type === "child_usage_attributed") {
+				const attribution = entry as ChildUsageAttributionEntry;
+				if (assistantUsageById.has(attribution.targetId)) {
+					assistantUsageById.set(attribution.targetId, attribution.aggregateUsage);
+					attributedChildUsages.push(attribution.childUsage);
+				}
+			}
+			if (entry.type === "compaction" || entry.type === "branch_summary") {
+				const summarizationUsage = (entry as CompactionEntry | BranchSummaryEntry).usage;
+				if (summarizationUsage) summarizationUsages.push(summarizationUsage);
+			}
 			if (!header) {
 				if (entry.type !== "session") {
 					return null;
@@ -1013,6 +1037,9 @@ async function scanSessionInfo(filePath: string, stats: Awaited<ReturnType<typeo
 			messageCount++;
 
 			const message = (entry as SessionMessageEntry).message;
+			if (message.role === "assistant" && (message as { usage?: Usage }).usage) {
+				assistantUsageById.set(entry.id, (message as { usage: Usage }).usage);
+			}
 			if (!isMessageWithContent(message)) continue;
 			if (message.role !== "user" && message.role !== "assistant") continue;
 
@@ -1026,6 +1053,16 @@ async function scanSessionInfo(filePath: string, stats: Awaited<ReturnType<typeo
 		}
 
 		if (!header) return null;
+		const usageTotal = emptyUsage();
+		for (const usage of assistantUsageById.values()) {
+			addAssistantUsage(usageTotal, usage);
+		}
+		for (const usage of summarizationUsages) {
+			addAssistantUsage(usageTotal, usage);
+		}
+		for (const childUsage of attributedChildUsages) {
+			subtractAssistantUsage(usageTotal, childUsage);
+		}
 		const cwd = typeof header.cwd === "string" ? header.cwd : "";
 		const parentSessionPath = header.parentSession;
 		const rlmDepth = resolveSessionRlmDepth(header, filePath);
@@ -1045,6 +1082,7 @@ async function scanSessionInfo(filePath: string, stats: Awaited<ReturnType<typeo
 			firstMessage: firstMessage || "(no messages)",
 			allMessagesText,
 			agentStatus,
+			usage: sessionUsageSummaryFrom(usageTotal),
 		};
 	} catch {
 		return null;
@@ -1447,6 +1485,7 @@ export class SessionManager {
 		details?: T,
 		fromHook?: boolean,
 		customInstructions?: string,
+		usage?: Usage,
 	): string {
 		const entry: CompactionEntry<T> = {
 			type: "compaction",
@@ -1459,6 +1498,7 @@ export class SessionManager {
 			details,
 			fromHook,
 			customInstructions,
+			usage,
 		};
 		this._appendEntry(entry);
 		return entry.id;
@@ -1836,7 +1876,13 @@ export class SessionManager {
 		this.leafId = null;
 	}
 
-	branchWithSummary(branchFromId: string | null, summary: string, details?: unknown, fromHook?: boolean): string {
+	branchWithSummary(
+		branchFromId: string | null,
+		summary: string,
+		details?: unknown,
+		fromHook?: boolean,
+		usage?: Usage,
+	): string {
 		if (branchFromId !== null && !this.byId.has(branchFromId)) {
 			throw new Error(`Entry ${branchFromId} not found`);
 		}
@@ -1850,6 +1896,7 @@ export class SessionManager {
 			summary,
 			details,
 			fromHook,
+			usage,
 		};
 		this._appendEntry(entry);
 		return entry.id;