feat(usage): resolve reports from active session accounts

Resolve source inputs at fetch time so model and credential changes select the account each session spends. Keep the legacy discovered-account RPC for existing clients. Sync OpenCode model events outside foreground turns so usage follows model switches.

packages/server/src/plugins/index.ts

@@ -8,6 +8,7 @@ import grokUsageSource from "./grok-usage-source/index.server.js";
 import kimiUsageSource from "./kimi-usage-source/index.server.js";
 import minimaxUsageSource from "./minimax-usage-source/index.server.js";
 import zaiUsageSource from "./zai-usage-source/index.server.js";
+import opencodeGoUsageSource from "./opencode-go-usage-source/index.server.js";
 
 export interface InternalPlugin {
   id: string;
@@ -56,4 +57,9 @@ export const INTERNAL_PLUGINS: InternalPlugin[] = [
     directory: fileURLToPath(new URL("./zai-usage-source/", import.meta.url)),
     contribute: zaiUsageSource,
   },
+  {
+    id: "opencode-go-usage-source",
+    directory: fileURLToPath(new URL("./opencode-go-usage-source/", import.meta.url)),
+    contribute: opencodeGoUsageSource,
+  },
 ];

packages/server/src/plugins/opencode-go-usage-source/icon.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><circle cx="12" cy="12" r="9" fill="#1a1a1a"/><path d="M7 12h10M12 7v10" stroke="white" stroke-width="2"/></svg>

packages/server/src/plugins/opencode-go-usage-source/index.server.ts

@@ -0,0 +1,14 @@
+import type { PluginServerContext } from "@getpaseo/plugin/server";
+import { inputSchema } from "./shared/input.js";
+import { fetchUsage } from "./server/usage.js";
+
+export default function contribute(server: PluginServerContext) {
+  server.registerUsageSource({
+    id: "opencode-go",
+    label: "OpenCode Go",
+    icon: "icon.svg",
+    input: inputSchema,
+    fetch: fetchUsage,
+  });
+  return () => {};
+}

packages/server/src/plugins/opencode-go-usage-source/paseo-plugin.json

@@ -0,0 +1 @@
+{ "id": "opencode-go-usage-source", "requirements": { "paseo": ">=0.9.2" } }

packages/server/src/plugins/opencode-go-usage-source/server/usage.test.ts

@@ -0,0 +1,34 @@
+import { expect, test } from "vitest";
+import { fetchUsage } from "./usage.js";
+
+test("reads the OpenCode Go usage windows", async () => {
+  const requests: Array<{ url: string; authorization: string | null }> = [];
+  const fetchApi = async (url: string | URL | Request, init?: RequestInit) => {
+    const headers = new Headers(init?.headers);
+    requests.push({ url: String(url), authorization: headers.get("Authorization") });
+    return Response.json({
+      rollingUsage: { usagePercent: 21, resetInSec: 1800 },
+      weeklyUsage: { usagePercent: 42 },
+      monthlyUsage: { usagePercent: 63 },
+    });
+  };
+  const report = await fetchUsage({ apiKey: "fixture-key" }, fetchApi as typeof fetch);
+  expect(requests).toEqual([
+    { url: "https://opencode.ai/zen/go/v1/usage", authorization: "Bearer fixture-key" },
+  ]);
+  expect(report.status).toBe("available");
+  expect(report.windows.map((window) => [window.id, window.usedPct, window.headline])).toEqual([
+    ["rolling", 21, true],
+    ["weekly", 42, undefined],
+    ["monthly", 63, undefined],
+  ]);
+});
+
+test("treats rejected credentials as unavailable", async () => {
+  const report = await fetchUsage(
+    { apiKey: "fixture-key" },
+    async () => new Response(null, { status: 401 }),
+  );
+  expect(report.status).toBe("unavailable");
+  expect(report.windows).toEqual([]);
+});

packages/server/src/plugins/opencode-go-usage-source/server/usage.ts

@@ -0,0 +1,57 @@
+import { createHash } from "node:crypto";
+import { z } from "zod";
+import {
+  toneFromUsedPct,
+  windowFromUsedPct,
+  type UsageReport,
+} from "@getpaseo/plugin/server/usage";
+import type { Input } from "../shared/input.js";
+
+const windowSchema = z
+  .object({ usagePercent: z.number().finite(), resetInSec: z.number().finite().optional() })
+  .passthrough();
+const responseSchema = z.object({
+  rollingUsage: windowSchema.optional(),
+  weeklyUsage: windowSchema.optional(),
+  monthlyUsage: windowSchema.optional(),
+});
+
+export async function fetchUsage(
+  input: Input,
+  fetchApi: typeof fetch = fetch,
+): Promise<UsageReport> {
+  const key = createHash("sha256").update(input.apiKey).digest("hex");
+  const response = await fetchApi("https://opencode.ai/zen/go/v1/usage", {
+    headers: { Authorization: `Bearer ${input.apiKey}`, Accept: "application/json" },
+    signal: AbortSignal.timeout(15_000),
+  });
+  if (response.status === 401 || response.status === 403)
+    return { account: { key }, status: "unavailable", windows: [] };
+  if (!response.ok) throw new Error(`OpenCode Go usage API returned ${response.status}`);
+  const data = responseSchema.parse(await response.json());
+  const now = Date.now();
+  const windows = (
+    [
+      ["rolling", "Rolling", data.rollingUsage],
+      ["weekly", "Weekly", data.weeklyUsage],
+      ["monthly", "Monthly", data.monthlyUsage],
+    ] as const
+  ).flatMap(([id, label, value]) =>
+    value
+      ? [
+          windowFromUsedPct({
+            id,
+            label,
+            utilizationPct: value.usagePercent,
+            resetsAt:
+              value.resetInSec === undefined
+                ? null
+                : new Date(now + value.resetInSec * 1000).toISOString(),
+            tone: toneFromUsedPct(value.usagePercent),
+            headline: id === "rolling",
+          }),
+        ]
+      : [],
+  );
+  return { account: { key }, status: "available", planLabel: "Go", windows };
+}

packages/server/src/plugins/opencode-go-usage-source/shared/input.ts

@@ -0,0 +1,4 @@
+import { z } from "zod";
+
+export const inputSchema = z.object({ apiKey: z.string().min(1) }).strict();
+export type Input = z.infer<typeof inputSchema>;

packages/server/src/server/agent/agent-sdk-types.ts

@@ -668,6 +668,8 @@ export interface AgentSession {
   /** New provider-owned rows to commit on registration. streamHistory must also
    * replay them at their original timestamps; restored sessions omit old rows. */
   readonly initialTimeline?: ImportedTimelineEntry[];
+  /** Resolved at fetch time because model and credentials may change during a session. */
+  getUsageReference?(): Promise<{ source: string; input: JsonValue } | null>;
   run(prompt: AgentPromptInput, options?: AgentRunOptions): Promise<AgentRunResult>;
   startTurn(prompt: AgentPromptInput, options?: AgentRunOptions): Promise<{ turnId: string }>;
   steerActiveTurn?(prompt: AgentPromptInput, options: SteerActiveTurnOptions): Promise<SteerResult>;

packages/server/src/server/agent/plugin-provider.test.ts

@@ -396,6 +396,24 @@ describe("PluginAgentClientRegistry", () => {
     await registry.shutdown();
   });
 
+  test("returns no usage reference when a plugin provider lacks the capability", async () => {
+    const harness = createProviderHarness();
+    const registry = new PluginAgentClientRegistry(createTestLogger());
+    registry.replace([harness.registration]);
+    const client = registry.clients()[harness.registration.id]!;
+    const session = await client.createSession({
+      provider: harness.registration.id,
+      cwd: "/workspace",
+    });
+    try {
+      expect(await session.getUsageReference?.()).toBeNull();
+      expect(harness.inputs.some((input) => input.type === "session.usage_reference")).toBe(false);
+    } finally {
+      await session.close();
+      registry.replace([]);
+    }
+  });
+
   test("terminalizes an active turn exactly once when its plugin provider is removed", async () => {
     const harness = createProviderHarness({ completeTurn: false });
     const registry = new PluginAgentClientRegistry(createTestLogger());

packages/server/src/server/agent/plugin-provider.ts

@@ -105,6 +105,20 @@ function providerError(error: ProviderError): Error {
   });
 }
 
+function isProviderRequestReply(
+  event: ProviderEvent,
+): event is Extract<
+  ProviderEvent,
+  { type: "request.completed" | "catalog" | "sessions" | "usage_reference" }
+> {
+  return (
+    event.type === "request.completed" ||
+    event.type === "catalog" ||
+    event.type === "sessions" ||
+    event.type === "usage_reference"
+  );
+}
+
 class ProviderRuntime {
   private connection: ProviderConnection | null = null;
   private connecting: Promise<ProviderConnection> | null = null;
@@ -356,11 +370,7 @@ class ProviderRuntime {
       this.failRequest(event);
       return;
     }
-    if (
-      event.type === "request.completed" ||
-      event.type === "catalog" ||
-      event.type === "sessions"
-    ) {
+    if (isProviderRequestReply(event)) {
       this.finishRequest(event);
       return;
     }
@@ -515,7 +525,10 @@ class ProviderRuntime {
   }
 
   private finishRequest(
-    event: Extract<ProviderEvent, { type: "request.completed" | "catalog" | "sessions" }>,
+    event: Extract<
+      ProviderEvent,
+      { type: "request.completed" | "catalog" | "sessions" | "usage_reference" }
+    >,
   ): void {
     const request = this.requests.get(event.requestId);
     if (!request) return;
@@ -554,6 +567,17 @@ class ProviderRuntimeSession {
     return this.capabilities;
   }
 
+  async getUsageReference(): Promise<{ source: string; input: JsonValue } | null> {
+    if (!this.capabilities.includes("session.usage_reference")) return null;
+    const event = await this.runtime.complete({
+      type: "session.usage_reference",
+      requestId: randomUUID(),
+      sessionId: this.providerSessionId,
+    });
+    if (event.type !== "usage_reference") throw new Error("Invalid usage reference response");
+    return event.reference;
+  }
+
   onEvent(listener: (event: ProviderEvent) => void): () => void {
     this.listeners.add(listener);
     return () => this.listeners.delete(listener);
@@ -1063,6 +1087,10 @@ class PluginAgentSession implements AgentSession {
     return agentCapabilities(this.bridge.negotiatedCapabilities);
   }
 
+  getUsageReference(): Promise<{ source: string; input: JsonValue } | null> {
+    return this.bridge.getUsageReference();
+  }
+
   get features(): AgentFeature[] {
     return this.bridge.config.settings.map((setting) =>
       setting.type === "toggle"

packages/server/src/server/agent/providers/acp-agent.test.ts

@@ -222,6 +222,13 @@ function createSessionWithConfig(
   );
 }
 
+test("ACP usage reference uses the provider ID", async () => {
+  for (const provider of ["copilot", "cursor", "kimi", "custom-source"]) {
+    const session = createSessionWithConfig({ provider });
+    expect(await session.getUsageReference()).toEqual({ source: provider, input: {} });
+  }
+});
+
 function createKiroSession(
   options: { waitForInitialCommands?: boolean; initialCommandsWaitTimeoutMs?: number } = {},
   logger: ReturnType<typeof createTestLogger> = createTestLogger(),

packages/server/src/server/agent/providers/acp-agent.ts

@@ -1633,6 +1633,10 @@ export class ACPAgentSession implements AgentSession, ACPClient {
   readonly provider: string;
   readonly capabilities: AgentCapabilityFlags;
 
+  async getUsageReference() {
+    return { source: this.provider, input: {} };
+  }
+
   private readonly logger: Logger;
   private readonly runtimeSettings?: ProviderRuntimeSettings;
   private readonly defaultCommand: [string, ...string[]];

packages/server/src/server/agent/providers/claude/agent.test.ts

@@ -527,6 +527,25 @@ describe("ClaudeAgentClient.fetchCatalog", () => {
 describe("ClaudeAgentClient binary resolution", () => {
   const logger = createTestLogger();
 
+  test("Claude usage reference follows CLAUDE_CONFIG_DIR and excludes API overrides", async () => {
+    const client = new ClaudeAgentClient({ logger, resolveBinary: async () => "/test/claude/bin" });
+    const session = await client.createSession(
+      { provider: "claude", cwd: process.cwd() },
+      { env: { CLAUDE_CONFIG_DIR: "/accounts/second" } },
+    );
+    expect(await session.getUsageReference?.()).toEqual({
+      source: "claude",
+      input: { configDir: "/accounts/second" },
+    });
+    await session.close();
+    const custom = await client.createSession(
+      { provider: "claude", cwd: process.cwd() },
+      { env: { ANTHROPIC_AUTH_TOKEN: "token" } },
+    );
+    expect(await custom.getUsageReference?.()).toBeNull();
+    await custom.close();
+  });
+
   test("resolves the installed Claude Code version", async () => {
     await expect(resolveClaudeCodeVersion()).resolves.toMatch(/^\d+\.\d+\.\d+$/);
   });

packages/server/src/server/agent/providers/claude/agent.ts

@@ -3,6 +3,7 @@ import { randomUUID } from "node:crypto";
 import fs from "node:fs";
 import { promises } from "node:fs";
 import path from "node:path";
+import { homedir } from "node:os";
 import {
   type AgentDefinition,
   type CanUseTool,
@@ -2041,6 +2042,15 @@ class ClaudeAgentSession implements AgentSession {
   readonly provider = "claude" as const;
   readonly capabilities = CLAUDE_CAPABILITIES;
 
+  async getUsageReference() {
+    const env = this.buildSdkEnv();
+    if (env.ANTHROPIC_BASE_URL || env.ANTHROPIC_API_KEY || env.ANTHROPIC_AUTH_TOKEN) return null;
+    return {
+      source: "claude",
+      input: { configDir: env.CLAUDE_CONFIG_DIR || path.join(env.HOME || homedir(), ".claude") },
+    };
+  }
+
   private readonly config: ClaudeAgentConfig;
   private readonly launchEnv?: Record<string, string>;
   private readonly agentId?: string;

packages/server/src/server/agent/providers/codex-app-server-agent.test.ts

@@ -171,6 +171,44 @@ function createSession(
   return session;
 }
 
+test("Codex usage reference follows CODEX_HOME and excludes custom base URLs", async () => {
+  const session = new CodexAppServerAgentSession(
+    createConfig(),
+    null,
+    createTestLogger(),
+    () => {
+      throw new Error("unused");
+    },
+    {},
+    false,
+    false,
+    false,
+    undefined,
+    "interactive",
+    { CODEX_HOME: "/accounts/second" },
+  );
+  expect(await session.getUsageReference()).toEqual({
+    source: "codex",
+    input: { codexHome: "/accounts/second" },
+  });
+  const custom = new CodexAppServerAgentSession(
+    createConfig(),
+    null,
+    createTestLogger(),
+    () => {
+      throw new Error("unused");
+    },
+    {},
+    false,
+    false,
+    false,
+    undefined,
+    "interactive",
+    { CODEX_HOME: "/accounts/second", OPENAI_BASE_URL: "https://example.test" },
+  );
+  expect(await custom.getUsageReference()).toBeNull();
+});
+
 function createProviderWithFakeAppServer(
   appServer: FakeCodexAppServer,
   options?: {

packages/server/src/server/agent/providers/codex-app-server-agent.ts

@@ -3453,6 +3453,7 @@ export class CodexAppServerAgentSession implements AgentSession {
     private readonly autoReviewEnabled: boolean = false,
     private readonly agentId?: string,
     private readonly initialResumePurpose: "interactive" | "history" = "interactive",
+    private readonly usageEnv: NodeJS.ProcessEnv = process.env,
   ) {
     this.logger = logger.child({
       module: "agent",
@@ -3481,6 +3482,17 @@ export class CodexAppServerAgentSession implements AgentSession {
     }
   }
 
+  async getUsageReference() {
+    if (this.usageEnv.OPENAI_BASE_URL) return null;
+    return {
+      source: "codex",
+      input: {
+        codexHome:
+          this.usageEnv.CODEX_HOME || path.join(this.usageEnv.HOME || os.homedir(), ".codex"),
+      },
+    };
+  }
+
   get id(): string | null {
     return this.currentThreadId;
   }
@@ -7143,6 +7155,8 @@ export class CodexAppServerAgentClient implements AgentClient {
       goalsEnabled,
       autoReviewEnabled,
       launchContext?.agentId,
+      "interactive",
+      buildCodexAppServerEnv(this.runtimeSettings, launchContext?.env),
     );
     await session.connect();
     return session;
@@ -7175,6 +7189,7 @@ export class CodexAppServerAgentClient implements AgentClient {
       autoReviewEnabled,
       launchContext?.agentId,
       options?.purpose ?? "interactive",
+      buildCodexAppServerEnv(this.runtimeSettings, launchContext?.env),
     );
     await session.connect();
     return session;

packages/server/src/server/agent/providers/opencode-agent.test.ts

@@ -333,6 +333,65 @@ describe("OpenCodeAgentClient adapter smoke tests", () => {
     model: TEST_MODEL,
   });
 
+  test("usage reference follows the active OpenCode model and OAuth account", async () => {
+    const cwd = tmpCwd();
+    const runtime = new TestOpenCodeHarness();
+    const openCode = new TestOpenCodeClient();
+    runtime.enqueueClient(openCode);
+    const client = new OpenCodeAgentClient(
+      logger,
+      {
+        env: {
+          OPENCODE_AUTH_CONTENT: JSON.stringify({
+            openai: { type: "oauth", access: "oauth-token", accountId: "acct-1" },
+            "opencode-go": { type: "api", key: "go-key" },
+          }),
+        },
+      },
+      { serverManager: runtime, createClient: runtime.createClient },
+    );
+    const session = await client.createSession(buildConfig(cwd));
+    await session.setModel?.("openai/gpt-5");
+    expect(await session.getUsageReference?.()).toEqual({
+      source: "codex",
+      input: { accessToken: "oauth-token", accountId: "acct-1" },
+    });
+    await session.setModel?.("opencode-go/qwen");
+    expect(await session.getUsageReference?.()).toEqual({
+      source: "opencode-go",
+      input: { apiKey: "go-key" },
+    });
+    await session.setModel?.("other/model");
+    expect(await session.getUsageReference?.()).toBeNull();
+    const events: AgentStreamEvent[] = [];
+    session.subscribe((event) => events.push(event));
+    const sessionId = (await session.getRuntimeInfo()).sessionId;
+    openCode.emitEvent({
+      type: "message.updated",
+      properties: {
+        info: {
+          id: "msg_changed_model",
+          sessionID: sessionId,
+          role: "user",
+          model: { providerID: "openai", modelID: "gpt-5" },
+        },
+      },
+    } as OpenCodeEvent);
+    await vi.waitFor(async () =>
+      expect(await session.getUsageReference?.()).toEqual({
+        source: "codex",
+        input: { accessToken: "oauth-token", accountId: "acct-1" },
+      }),
+    );
+    expect(events).toContainEqual({
+      type: "model_changed",
+      provider: "opencode",
+      runtimeInfo: { provider: "opencode", sessionId, model: "openai/gpt-5", modeId: null },
+    });
+    await session.close();
+    rmSync(cwd, { recursive: true, force: true });
+  });
+
   test("creates a session with valid id and provider", async () => {
     const cwd = tmpCwd();
     const runtime = new TestOpenCodeHarness();

packages/server/src/server/agent/providers/opencode-agent.ts

@@ -12,6 +12,8 @@ import {
   type TextPartInput as OpenCodeTextPartInput,
 } from "@opencode-ai/sdk/v2/client";
 import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
 import { randomBytes } from "node:crypto";
 import { isDeepStrictEqual } from "node:util";
 import { createPathEquivalenceMatcher } from "../../../utils/path.js";
@@ -1500,6 +1502,7 @@ export class OpenCodeAgentClient implements AgentClient {
         false,
         unbindBridge,
         connectServer,
+        { ...process.env, ...this.runtimeSettings?.env, ...launchContext?.env },
       );
     } catch (error) {
       await connection.release();
@@ -1554,6 +1557,7 @@ export class OpenCodeAgentClient implements AgentClient {
         registeredAcquisition !== null,
         unbindBridge,
         connectServer,
+        { ...process.env, ...this.runtimeSettings?.env, ...launchContext?.env },
       );
     } catch (error) {
       await connection.release();
@@ -3279,7 +3283,7 @@ function isOpenCodeTerminalEvent(event: OpenCodeEvent, sessionId: string): boole
 }
 
 function isOpenCodeProviderInternalEvent(event: AgentStreamEvent): boolean {
-  return event.type === "provider_subagent";
+  return event.type === "provider_subagent" || event.type === "model_changed";
 }
 
 function readOpenCodeChildSessionInfo(value: unknown): OpenCodeChildSessionInfo | null {
@@ -3360,6 +3364,56 @@ interface OpenCodeServerConnection {
   release: () => Promise<void>;
 }
 
+async function readOpenCodeUsageAuth(
+  env: NodeJS.ProcessEnv,
+): Promise<Record<string, unknown> | null> {
+  try {
+    const content =
+      env.OPENCODE_AUTH_CONTENT ??
+      (await fs.readFile(
+        path.join(
+          env.XDG_DATA_HOME || path.join(env.HOME || os.homedir(), ".local", "share"),
+          "opencode",
+          "auth.json",
+        ),
+        "utf8",
+      ));
+    const parsed: unknown = JSON.parse(content);
+    return parsed && typeof parsed === "object" && !Array.isArray(parsed)
+      ? (parsed as Record<string, unknown>)
+      : null;
+  } catch {
+    return null;
+  }
+}
+
+function resolveOpenCodeUsageReference(
+  model: string,
+  auth: Record<string, unknown> | null,
+): { source: string; input: import("@getpaseo/protocol/agent-types").JsonValue } | null {
+  if (!auth) return null;
+  if (model.startsWith("openai/")) {
+    const entry = auth.openai;
+    if (!entry || typeof entry !== "object") return null;
+    const credential = entry as Record<string, unknown>;
+    if (credential.type !== "oauth" || typeof credential.access !== "string" || !credential.access)
+      return null;
+    return {
+      source: "codex",
+      input: {
+        accessToken: credential.access,
+        ...(typeof credential.accountId === "string" ? { accountId: credential.accountId } : {}),
+      },
+    };
+  }
+  const entry = auth["opencode-go"];
+  if (!entry || typeof entry !== "object") return null;
+  const credential = entry as Record<string, unknown>;
+  if (credential.type !== "api" || typeof credential.key !== "string" || !credential.key)
+    return null;
+  return { source: "opencode-go", input: { apiKey: credential.key } };
+}
+
 class OpenCodeAgentSession implements AgentSession {
   readonly provider = "opencode" as const;
   readonly capabilities = OPENCODE_CAPABILITIES;
@@ -3448,6 +3502,7 @@ class OpenCodeAgentSession implements AgentSession {
     private readonly externallyDriven = false,
     releaseBridge?: () => void,
     connectServer?: () => Promise<OpenCodeServerConnection>,
+    private readonly usageEnv: NodeJS.ProcessEnv = process.env,
   ) {
     this.config = config;
     this.server = { client, events, url: serverUrl ?? "", release: releaseServer };
@@ -3552,6 +3607,16 @@ class OpenCodeAgentSession implements AgentSession {
     };
   }
 
+  async getUsageReference(): Promise<{
+    source: string;
+    input: import("@getpaseo/protocol/agent-types").JsonValue;
+  } | null> {
+    const model = this.config.model;
+    if (!model?.startsWith("openai/") && !model?.startsWith("opencode-go/")) return null;
+    const auth = await readOpenCodeUsageAuth(this.usageEnv);
+    return resolveOpenCodeUsageReference(model, auth);
+  }
+
   async setModel(modelId: string | null): Promise<void> {
     const normalizedModelId =
       typeof modelId === "string" && modelId.trim().length > 0 ? modelId : null;
@@ -5346,6 +5411,7 @@ class OpenCodeAgentSession implements AgentSession {
 
   private async translateEvent(event: OpenCodeEvent): Promise<AgentStreamEvent[]> {
     const eventSessionId = getOpenCodeEventSessionId(event);
+    const runtimeModelChanged = this.syncRuntimeModel(event, eventSessionId);
     if (
       event.type !== "session.created" &&
       eventSessionId &&
@@ -5362,6 +5428,12 @@ class OpenCodeAgentSession implements AgentSession {
       }
     }
     const translated = translateOpenCodeEvent(event, this.createTranslationState());
+    if (runtimeModelChanged)
+      translated.push({
+        type: "model_changed",
+        provider: this.provider,
+        runtimeInfo: await this.getRuntimeInfo(),
+      });
     this.appendProviderSubagentEvents(event, translated);
 
     const events: AgentStreamEvent[] = [];
@@ -5402,6 +5474,20 @@ class OpenCodeAgentSession implements AgentSession {
     return events;
   }
 
+  private syncRuntimeModel(event: OpenCodeEvent, eventSessionId: string | null): boolean {
+    if (event.type !== "message.updated" || eventSessionId !== this.sessionId) return false;
+    const info = event.properties.info;
+    let model: string | undefined;
+    if (info.role === "assistant") model = resolveOpenCodeModelLookupKeyFromAssistantMessage(info);
+    if (info.role === "user" && info.model)
+      model = buildOpenCodeModelLookupKey(info.model.providerID, info.model.modelID);
+    if (!model || model === this.config.model) return false;
+    this.config.model = model;
+    this.selectedModelContextWindowMaxTokens =
+      this.resolveConfiguredModelContextWindowMaxTokens(model);
+    return true;
+  }
+
   private async tryAutoApproveToolPermission(
     request: AgentPermissionRequest,
     directory: string,

packages/server/src/server/agent/providers/pi/agent.test.ts

@@ -23,7 +23,7 @@ import {
   PiRpcAgentSession,
   transformPiModels,
 } from "./agent.js";
-import { FakePi } from "./test-utils/fake-pi.js";
+import { FakePi, type FakePiSession } from "./test-utils/fake-pi.js";
 import { createPiExtensionHost } from "./extensions/index.js";
 import { PiExtensionHost } from "./extensions/host.js";
 import type { PiModel, PiThinkingLevel } from "./rpc-types.js";
@@ -202,6 +202,57 @@ async function createSession(
   return { pi, session, events };
 }
 
+test("Pi usage reference follows the current OAuth model and agent directory", async () => {
+  const agentDir = mkdtempSync(path.join(tmpdir(), "paseo-pi-usage-"));
+  try {
+    writeFileSync(
+      path.join(agentDir, "auth.json"),
+      JSON.stringify({
+        "openai-codex": {
+          type: "oauth",
+          access: "codex-token",
+          refresh: "refresh",
+          expires: Date.now() + 60_000,
+        },
+        anthropic: {
+          type: "oauth",
+          access: "claude-token",
+          refresh: "refresh",
+          expires: Date.now() + 60_000,
+        },
+      }),
+    );
+    const pi = new FakePi();
+    let runtime!: FakePiSession;
+    pi.queueSessionSetup((sessionRuntime) => {
+      runtime = sessionRuntime;
+      runtime.state.model = { provider: "openai-codex", id: "gpt", name: "GPT" };
+    });
+    const session = await createClient(pi).createSession(createConfig(), {
+      env: { PI_CODING_AGENT_DIR: agentDir },
+    });
+    expect(await session.getUsageReference?.()).toEqual({
+      source: "codex",
+      input: { accessToken: "codex-token" },
+    });
+    runtime.state.model = { provider: "anthropic", id: "claude", name: "Claude" };
+    expect(await session.getUsageReference?.()).toEqual({
+      source: "claude",
+      input: { accessToken: "claude-token" },
+    });
+    writeFileSync(
+      path.join(agentDir, "auth.json"),
+      JSON.stringify({ anthropic: { type: "api_key", key: "api-key" } }),
+    );
+    expect(await session.getUsageReference?.()).toBeNull();
+    runtime.state.model = { provider: "other", id: "other", name: "Other" };
+    expect(await session.getUsageReference?.()).toBeNull();
+    await session.close();
+  } finally {
+    rmSync(agentDir, { recursive: true, force: true });
+  }
+});
+
 test("forwards launch-context env to the Pi process launch", async () => {
   const pi = new FakePi();
   const client = createClient(pi);

packages/server/src/server/agent/providers/pi/agent.ts

@@ -242,6 +242,7 @@ interface PiRpcAgentSessionOptions {
   extensionTimeoutMs?: number;
   logger: Logger;
   usagePollScheduler?: PiUsagePollScheduler;
+  usageEnv?: Record<string, string>;
 }
 
 interface PiResumeConfig {
@@ -1122,6 +1123,32 @@ export class PiRpcAgentSession implements AgentSession {
   readonly provider: AgentProvider;
   readonly capabilities: AgentCapabilityFlags;
 
+  async getUsageReference() {
+    await this.refreshState();
+    const provider = this.state.model?.provider;
+    let source: string | null = null;
+    if (provider === "openai-codex") source = "codex";
+    if (provider === "anthropic") source = "claude";
+    if (!source || !provider) return null;
+    try {
+      const credentials = JSON.parse(
+        readFileSync(join(resolvePiAgentDir(this.usageEnv), "auth.json"), "utf8"),
+      ) as Record<string, unknown>;
+      const entry = credentials[provider];
+      if (!entry || typeof entry !== "object") return null;
+      const credential = entry as Record<string, unknown>;
+      if (
+        credential.type !== "oauth" ||
+        typeof credential.access !== "string" ||
+        !credential.access
+      )
+        return null;
+      return { source, input: { accessToken: credential.access } };
+    } catch {
+      return null;
+    }
+  }
+
   private readonly subscribers = new Set<(event: AgentStreamEvent) => void>();
   private readonly activeToolCalls = new Map<string, PiTrackedToolCall>();
   private readonly pendingExtensionUiRequests = new Map<string, AgentPermissionRequest>();
@@ -1149,6 +1176,7 @@ export class PiRpcAgentSession implements AgentSession {
   private readonly currentModeId: string | null;
   private readonly logger: Logger;
   private readonly usagePoller: PiUsagePoller;
+  private readonly usageEnv?: Record<string, string>;
   private closed = false;
   private readonly closeController = new AbortController();
   private readonly pendingExtensionHydrations = new Set<Promise<void>>();
@@ -1168,6 +1196,7 @@ export class PiRpcAgentSession implements AgentSession {
     this.extensionTimeoutMs = options.extensionTimeoutMs ?? DEFAULT_PI_EXTENSION_RESULT_TIMEOUT_MS;
     this.logger = options.logger;
     this.extensionHost = createPiExtensionHost(this.logger);
+    this.usageEnv = options.usageEnv;
     this.usagePoller = new PiUsagePoller({
       scheduler: options.usagePollScheduler,
       readStats: () => this.runtimeSession.getSessionStats(),
@@ -2461,6 +2490,7 @@ export class PiRpcAgentClient implements AgentClient {
         extensionTimeoutMs: this.providerParams.extensionTimeoutMs,
         logger: this.logger,
         usagePollScheduler: this.usagePollScheduler,
+        usageEnv: mcpEnv,
       });
     } catch (error) {
       await runtimeSession.close().catch(() => undefined);
@@ -2524,6 +2554,7 @@ export class PiRpcAgentClient implements AgentClient {
         extensionTimeoutMs: this.providerParams.extensionTimeoutMs,
         logger: this.logger,
         usagePollScheduler: this.usagePollScheduler,
+        usageEnv: mcpEnv,
       });
     } catch (error) {
       await runtimeSession.close().catch(() => undefined);

packages/server/src/server/authorization/operation-permissions.ts

@@ -150,6 +150,7 @@ const INBOUND_PERMISSION = {
   project_icon_request: "workspace.read",
   "provider.usage.list.request": "daemon.read",
   "usage.list_reports.request": "daemon.read",
+  "agent.get_usage_report.request": "daemon.read",
   provider_diagnostic_request: "daemon.read",
   pull_request_timeline_request: "workspace.read",
   "push.unregister.request": "workspace.read",
@@ -375,6 +376,7 @@ const OUTBOUND_PERMISSION = {
   project_icon_response: "workspace.read",
   "provider.usage.list.response": "daemon.read",
   "usage.list_reports.response": "daemon.read",
+  "agent.get_usage_report.response": "daemon.read",
   provider_diagnostic_response: "daemon.read",
   providers_snapshot_update: ["daemon.read", "hub.execute"],
   pull_request_timeline_response: "workspace.read",

packages/server/src/server/plugins/index.ts

@@ -142,10 +142,20 @@ export class PluginService {
     return [...this.providers.values()].sort((left, right) => left.id.localeCompare(right.id));
   }
 
-  listUsageReports(options?: { forceRefresh?: boolean }) {
+  listUsageReports(options?: {
+    forceRefresh?: boolean;
+    references?: Array<{ source: string; input: unknown }>;
+  }) {
     return this.usageSources.listReports(options);
   }
 
+  fetchUsageReference(
+    reference: { source: string; input: unknown },
+    options?: { forceRefresh?: boolean },
+  ) {
+    return this.usageSources.fetchReference(reference, options);
+  }
+
   listLegacyUsage() {
     return this.usageSources.listLegacyUsage();
   }

packages/server/src/server/plugins/session-usage-reference.e2e.test.ts

@@ -0,0 +1,33 @@
+import { fileURLToPath } from "node:url";
+import { expect, test } from "vitest";
+import { DaemonClient } from "../test-utils/daemon-client.js";
+import { createTestPaseoDaemon } from "../test-utils/paseo-daemon.js";
+import contribute from "./test-fixtures/session-usage-reference/index.server.js";
+
+test("resolves a provider plugin session reference through its usage source", async () => {
+  const directory = fileURLToPath(
+    new URL("./test-fixtures/session-usage-reference/", import.meta.url),
+  );
+  const daemon = await createTestPaseoDaemon({
+    pluginsEnabled: false,
+    internalPlugins: [{ id: "fixture-session-usage-reference", directory, contribute }],
+  });
+  const client = new DaemonClient({ url: `ws://127.0.0.1:${daemon.port}/ws` });
+  try {
+    await client.connect();
+    const agent = await client.createAgent({
+      provider: "fixture-session-provider",
+      cwd: directory,
+    });
+    const result = await client.getAgentUsageReport({ agentId: agent.id });
+    expect(result.entry).toMatchObject({
+      sourceId: "fixture-session-usage",
+      report: { account: { key: "from-session" }, windows: [{ usedPct: 31 }] },
+    });
+    const reports = await client.listUsageReports();
+    expect(reports.reports.map((entry) => entry.report.account.key)).toContain("from-session");
+  } finally {
+    await client.close();
+    await daemon.close();
+  }
+}, 60_000);

packages/server/src/server/plugins/test-fixtures/session-usage-reference/index.server.ts

@@ -0,0 +1,72 @@
+import type { PluginServerContext } from "@getpaseo/plugin/server";
+import {
+  negotiateProviderCapabilities,
+  type ProviderEvent,
+} from "@getpaseo/plugin/server/provider";
+import { z } from "zod";
+
+export default function contribute(server: PluginServerContext) {
+  server.registerUsageSource({
+    id: "fixture-session-usage",
+    label: "Fixture session usage",
+    input: z.object({ account: z.string() }).strict(),
+    fetch: async (input) => ({
+      account: { key: (input as { account: string }).account },
+      status: "available",
+      windows: [{ id: "hour", label: "Hour", usedPct: 31, headline: true }],
+    }),
+  });
+  server.registerProvider({
+    id: "fixture-session-provider",
+    label: "Fixture session provider",
+    async connect(request) {
+      const capabilities = negotiateProviderCapabilities(request.capabilities, [
+        "prompt.message",
+        "session.usage_reference",
+      ]);
+      const listeners = new Set<(event: ProviderEvent) => void>();
+      const emit = (event: ProviderEvent) => {
+        for (const listener of listeners) listener(event);
+      };
+      return {
+        version: 1,
+        capabilities,
+        async send(input) {
+          if (input.type === "catalog")
+            emit({
+              type: "catalog",
+              requestId: input.requestId,
+              catalog: { models: [{ id: "fixture", label: "Fixture" }], modes: [] },
+            });
+          if (input.type === "session.open") {
+            emit({
+              type: "session.opened",
+              requestId: input.requestId,
+              sessionId: input.sessionId,
+              capabilities,
+              restoration: "core",
+              cwd: input.config.cwd,
+            });
+            emit({ type: "session.ready", requestId: input.requestId, sessionId: input.sessionId });
+          }
+          if (input.type === "session.usage_reference")
+            emit({
+              type: "usage_reference",
+              requestId: input.requestId,
+              reference: { source: "fixture-session-usage", input: { account: "from-session" } },
+            });
+          if (input.type === "session.close")
+            emit({ type: "request.completed", requestId: input.requestId });
+        },
+        onEvent(listener) {
+          listeners.add(listener);
+          return () => listeners.delete(listener);
+        },
+        async close() {
+          listeners.clear();
+        },
+      };
+    },
+  });
+  return () => {};
+}

packages/server/src/server/plugins/test-fixtures/session-usage-reference/paseo-plugin.json

@@ -0,0 +1 @@
+{ "id": "fixture-session-usage-reference", "requirements": { "paseo": ">=0.9.2" } }

packages/server/src/server/plugins/usage-sources/index.test.ts

@@ -44,6 +44,24 @@ test("coalesces concurrent fetches and dedupes accounts", async () => {
   expect(await registry.listReports()).toHaveLength(1);
 });
 
+test("includes live session references and ignores unregistered sources", async () => {
+  const registry = new UsageSourceRegistry();
+  registry.register({
+    id: "fixture",
+    label: "Fixture",
+    discover: async () => [{ account: "default" }],
+    fetch: async (input) => report((input as { account: string }).account, 25),
+  });
+  const reports = await registry.listReports({
+    references: [
+      { source: "fixture", input: { account: "second" } },
+      { source: "missing", input: {} },
+    ],
+  });
+  expect(reports.map((entry) => entry.report.account.key)).toEqual(["default", "second"]);
+  expect(await registry.fetchReference({ source: "missing", input: {} })).toBeNull();
+});
+
 test("drops expired cached inputs on a later write", async () => {
   let now = 0;
   const registry = new UsageSourceRegistry(() => now, 100);

packages/server/src/server/plugins/usage-sources/index.ts

@@ -34,7 +34,12 @@ export class UsageSourceRegistry {
     for (const key of this.cache.keys()) if (key.startsWith(`${id}:`)) this.cache.delete(key);
   }
 
-  async listReports(options: { forceRefresh?: boolean } = {}): Promise<UsageReportEntry[]> {
+  async listReports(
+    options: {
+      forceRefresh?: boolean;
+      references?: Array<{ source: string; input: unknown }>;
+    } = {},
+  ): Promise<UsageReportEntry[]> {
     const discovered = await Promise.all(
       [...this.sources.values()].map(async (source) => {
         try {
@@ -47,11 +52,29 @@ export class UsageSourceRegistry {
       }),
     );
     const unique = new Map<string, UsageReportEntry>();
-    for (const entry of discovered.flat())
+    const referenced = await Promise.all(
+      (options.references ?? []).map(async (reference) => {
+        if (!this.sources.has(reference.source)) return null;
+        return this.fetch(reference.source, reference.input, options);
+      }),
+    );
+    for (const entry of [
+      ...discovered.flat(),
+      ...referenced.filter((result): result is UsageReportEntry => result !== null),
+    ])
       unique.set(`${entry.sourceId}:${entry.report.account.key}`, entry);
     return [...unique.values()];
   }
 
+  fetchReference(
+    reference: { source: string; input: unknown },
+    options: { forceRefresh?: boolean } = {},
+  ): Promise<UsageReportEntry | null> {
+    return this.sources.has(reference.source)
+      ? this.fetch(reference.source, reference.input, options)
+      : Promise.resolve(null);
+  }
+
   // COMPAT(providerUsageList): added in v0.9.3, remove after 2027-03-26.
   async listLegacyUsage(): Promise<{ fetchedAt: string; providers: ProviderUsage[] }> {
     const reports = await this.listReports();

packages/server/src/server/session.ts

@@ -509,7 +509,14 @@ export interface SessionOptions {
     subscribeSettings?(listener: (pluginId: string, settingsId: string) => void): () => void;
     catalog(): Array<{ id: string; clientBundle: string }>;
     invokePluginRpc(pluginId: string, method: string, input: unknown): Promise<unknown>;
-    listUsageReports(options?: { forceRefresh?: boolean }): Promise<UsageReportEntry[]>;
+    listUsageReports(options?: {
+      forceRefresh?: boolean;
+      references?: Array<{ source: string; input: unknown }>;
+    }): Promise<UsageReportEntry[]>;
+    fetchUsageReference(
+      reference: { source: string; input: unknown },
+      options?: { forceRefresh?: boolean },
+    ): Promise<UsageReportEntry | null>;
     listLegacyUsage(): Promise<{ fetchedAt: string; providers: ProviderUsage[] }>;
   };
   orchestrationSkills?: import("./orchestration-skills/index.js").OrchestrationSkills;
@@ -3005,6 +3012,8 @@ export class Session {
         return this.providerCatalogSession.handleProviderUsageListRequest(msg);
       case "usage.list_reports.request":
         return this.handleUsageListReportsRequest(msg);
+      case "agent.get_usage_report.request":
+        return this.handleAgentGetUsageReportRequest(msg);
       default:
         return undefined;
     }
@@ -3015,7 +3024,24 @@ export class Session {
   ): Promise<void> {
     try {
       if (!this.pluginRuntime) throw new Error("Plugin runtime is unavailable");
-      const reports = await this.pluginRuntime.listUsageReports({ forceRefresh: msg.forceRefresh });
+      const references = (
+        await Promise.all(
+          this.agentManager
+            .listAgents()
+            .map(async (agent) => agent.session?.getUsageReference?.().catch(() => null) ?? null),
+        )
+      ).filter(
+        (
+          reference,
+        ): reference is {
+          source: string;
+          input: import("@getpaseo/protocol/agent-types").JsonValue;
+        } => reference !== null,
+      );
+      const reports = await this.pluginRuntime.listUsageReports({
+        forceRefresh: msg.forceRefresh,
+        references,
+      });
       this.emit({
         type: "usage.list_reports.response",
         payload: { requestId: msg.requestId, reports },
@@ -3033,6 +3059,35 @@ export class Session {
     }
   }
 
+  private async handleAgentGetUsageReportRequest(
+    msg: Extract<SessionInboundMessage, { type: "agent.get_usage_report.request" }>,
+  ): Promise<void> {
+    try {
+      if (!this.pluginRuntime) throw new Error("Plugin runtime is unavailable");
+      const agent = this.agentManager.getAgent(msg.agentId);
+      const reference = (await agent?.session?.getUsageReference?.()) ?? null;
+      const entry = reference
+        ? await this.pluginRuntime.fetchUsageReference(reference, {
+            forceRefresh: msg.forceRefresh,
+          })
+        : null;
+      this.emit({
+        type: "agent.get_usage_report.response",
+        payload: { requestId: msg.requestId, entry },
+      });
+    } catch (error) {
+      this.emit({
+        type: "rpc_error",
+        payload: {
+          requestId: msg.requestId,
+          requestType: msg.type,
+          error: error instanceof Error ? error.message : String(error),
+          code: "agent_get_usage_report_failed",
+        },
+      });
+    }
+  }
+
   private dispatchTerminalMessage(msg: SessionInboundMessage): Promise<void> | undefined {
     switch (msg.type) {
       case "start_workspace_script_request":