fix(resume,status): show prior transcript on resume + honest baseline on context bar

Two related defects in how a session reloads.

Resume only seeded pi-agent-core's internal message list (so the model
had context) but never re-populated the UI reducer's state.messages.
The user dropped back into what looked like an empty chat — only the
"↻ Resumed from 3h ago" badge hinted that anything had been loaded.
Expose the resumed transcript through the agent bundle and seed the
reducer with it so the screen matches the model's actual context.

The context-fill bar showed 0% on a fresh session because we only
counted in-transcript message chars, ignoring the system prompt and
tool schemas — ~3k tokens of static context every turn carries. Add
that as a baseline in the fallback estimator so the bar starts at a
small honest non-zero and grows visibly with each turn. The accurate
turnUsage path is unchanged when the provider does report usage.

Author: halfaipg

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "codebase-cli",
-	"version": "2.0.0-pre.42",
+	"version": "2.0.0-pre.43",
 	"description": "Codebase CLI — a TypeScript coding agent on the pi-mono runtime. OAuth-aware, any LLM provider, single install.",
 	"keywords": [
 		"ai",

src/agent/agent.ts

@@ -1,6 +1,6 @@
 import { homedir } from "node:os";
 import { isAbsolute, join, resolve } from "node:path";
-import { Agent, type AgentEvent } from "@earendil-works/pi-agent-core";
+import { Agent, type AgentEvent, type AgentMessage } from "@earendil-works/pi-agent-core";
 import type { Model } from "@earendil-works/pi-ai";
 import { defaultOAuthConfig } from "../auth/cli.js";
 import { CredentialsStore } from "../auth/credentials.js";
@@ -88,6 +88,13 @@ export interface AgentBundle {
 	 * "Resumed from 3h ago · 47 messages". Undefined for fresh sessions.
 	 */
 	resumedFrom?: { updatedAt: number; messageCount: number };
+	/**
+	 * The transcript loaded from a resumed session. Pi-agent-core already
+	 * has these in its internal state — this exposes them so the UI's
+	 * reducer can show the prior conversation on screen, not just in the
+	 * model's context. Empty when starting fresh.
+	 */
+	resumedMessages: AgentMessage[];
 }
 
 export function createAgent(opts: CreateAgentOptions = {}): AgentBundle {
@@ -314,5 +321,6 @@ export function createAgent(opts: CreateAgentOptions = {}): AgentBundle {
 		diagnostics,
 		subscribe,
 		resumedFrom: resumed ? { updatedAt: resumed.updatedAt, messageCount: resumed.messages.length } : undefined,
+		resumedMessages: resumed?.messages ?? [],
 	};
 }

src/agent/events.test.ts

@@ -35,6 +35,28 @@ describe("initialState", () => {
 		expect(s.usage).toEqual(EMPTY_USAGE);
 		expect(s.model).toEqual(MODEL);
 	});
+
+	it("seeds messages from a resumed session so the UI shows prior turns", () => {
+		const prior: AgentMessage[] = [
+			{ role: "user", content: "from before", timestamp: 1 } as AgentMessage,
+			{
+				role: "assistant",
+				content: [{ type: "text", text: "hi" }],
+				api: "chat",
+				provider: "p",
+				model: "m",
+				usage: EMPTY_USAGE,
+				stopReason: "stop",
+				timestamp: 2,
+			} as AgentMessage,
+		];
+		const s = initialState(MODEL, prior);
+		expect(s.messages).toHaveLength(2);
+		expect(s.status).toBe("idle");
+		// Copy, not reference — caller mutating the source array must not
+		// reach into our state.
+		expect(s.messages).not.toBe(prior);
+	});
 });
 
 describe("reducer · user-prompt", () => {

src/agent/events.ts

@@ -10,9 +10,9 @@ export type Action =
 	| { type: "error"; message: string }
 	| { type: "reset" };
 
-export function initialState(model: ChatState["model"]): ChatState {
+export function initialState(model: ChatState["model"], messages: AgentMessage[] = []): ChatState {
 	return {
-		messages: [],
+		messages: [...messages],
 		tools: new Map(),
 		status: "idle",
 		usage: EMPTY_USAGE,

src/ui/App.tsx

@@ -80,7 +80,10 @@ interface ChatAppProps {
 function ChatApp({ bundle, onExit }: ChatAppProps) {
 	const [state, dispatch] = useReducer(
 		reducer,
-		initialState({ provider: bundle.model.provider, id: bundle.model.id, name: bundle.model.name }),
+		initialState(
+			{ provider: bundle.model.provider, id: bundle.model.id, name: bundle.model.name },
+			bundle.resumedMessages,
+		),
 	);
 	const [permRequest, setPermRequest] = useState<PermissionRequest | undefined>(bundle.permissions.current());
 	const [userQuery, setUserQuery] = useState<UserQuery | undefined>(bundle.userQueries.current());

src/ui/Status.test.ts

@@ -16,8 +16,11 @@ function baseState(): ChatState {
 }
 
 describe("estimateContextTokens", () => {
-	it("returns 0 for an empty conversation", () => {
-		expect(estimateContextTokens(baseState())).toBe(0);
+	it("returns the static-context baseline for an empty conversation", () => {
+		// The system prompt + tool schemas are always in context even with
+		// zero messages; the bar reflects that with a small non-zero seed.
+		expect(estimateContextTokens(baseState())).toBeGreaterThan(0);
+		expect(estimateContextTokens(baseState())).toBeLessThan(10_000);
 	});
 
 	it("prefers turnUsage.input + cacheRead when the provider reports them", () => {
@@ -52,9 +55,13 @@ describe("estimateContextTokens", () => {
 				} as AgentMessage,
 			],
 		};
-		// 11 ("hello world") + 400 (x's) = 411 chars; 411 / 4 = ~103 tokens
-		expect(estimateContextTokens(state)).toBeGreaterThan(95);
-		expect(estimateContextTokens(state)).toBeLessThan(115);
+		// 11 ("hello world") + 400 (x's) = 411 chars; 411 / 4 = ~103 tokens.
+		// Plus the static-context baseline. Verify the delta from the baseline
+		// is in the right neighborhood rather than asserting an exact total.
+		const baseline = estimateContextTokens(baseState());
+		const delta = estimateContextTokens(state) - baseline;
+		expect(delta).toBeGreaterThan(95);
+		expect(delta).toBeLessThan(115);
 	});
 
 	it("falls back when turnUsage is present but reports zero (proxy stripped usage)", () => {
@@ -70,7 +77,9 @@ describe("estimateContextTokens", () => {
 			},
 			messages: [{ role: "user", content: "x".repeat(400), timestamp: 1 } as AgentMessage],
 		};
-		expect(estimateContextTokens(state)).toBeGreaterThan(95);
+		// Above the baseline by ~100 tokens (the 400-char message).
+		const baseline = estimateContextTokens({ ...baseState(), turnUsage: state.turnUsage });
+		expect(estimateContextTokens(state) - baseline).toBeGreaterThan(95);
 	});
 
 	it("includes streaming content so the bar fills mid-turn, not just at message_end", () => {
@@ -133,7 +142,7 @@ describe("estimateContextTokens", () => {
 				} as unknown as AgentMessage,
 			],
 		};
-		// 800 / 4 = 200 tokens
-		expect(estimateContextTokens(state)).toBe(200);
+		// 800 / 4 = 200 tokens above the baseline.
+		expect(estimateContextTokens(state) - estimateContextTokens(baseState())).toBe(200);
 	});
 });

src/ui/Status.tsx

@@ -9,6 +9,16 @@ import { Throbber } from "./Throbber.js";
  * fallback when the provider doesn't return usage info on message_end. */
 const CHARS_PER_TOKEN = 4;
 
+/**
+ * Approximate static-context tokens the model sees on every turn but
+ * that aren't in state.messages: system prompt, MEMORY.md addendum, and
+ * the tool-schema definitions. Used to seed the context bar so it reads
+ * 1-2% on a fresh session instead of misleadingly showing 0%. The real
+ * input + cacheRead from turnUsage always wins when available — this is
+ * only the fallback's baseline.
+ */
+const STATIC_CONTEXT_TOKENS = 3000;
+
 interface StatusProps {
 	state: ChatState;
 	cwd?: string;
@@ -217,7 +227,7 @@ export function estimateContextTokens(state: ChatState): number {
 	let chars = 0;
 	for (const msg of state.messages) chars += messageChars(msg);
 	if (state.streaming) chars += messageChars(state.streaming);
-	return Math.round(chars / CHARS_PER_TOKEN);
+	return STATIC_CONTEXT_TOKENS + Math.round(chars / CHARS_PER_TOKEN);
 }
 
 function messageChars(message: AgentMessage): number {