diff --git a/packages/app/e2e/browser/usage-composer-pill.spec.ts b/packages/app/e2e/browser/usage-composer-pill.spec.ts
index 42df720db7..36e99f340c 100644
--- a/packages/app/e2e/browser/usage-composer-pill.spec.ts
+++ b/packages/app/e2e/browser/usage-composer-pill.spec.ts
@@ -1,7 +1,11 @@
 import type { UsageReportEntry } from "@getpaseo/protocol/messages";
 import { expect, test, type Page } from "../support/fixtures";
 import { expectComposerVisible, submitMessage } from "../support/helpers/composer";
-import { openAgentRoute, seedMockAgentWorkspace } from "../support/helpers/mock-agent";
+import {
+  openAgentRoute,
+  seedMockAgentWorkspace,
+  seedRunningMockAgentWorkspace,
+} from "../support/helpers/mock-agent";
 import { installUsageReportsFixture } from "../support/helpers/usage-reports";
 
 const REPORT_ID = "fixture:fixture-account";
@@ -42,6 +46,30 @@ async function openMockAgent(page: Page) {
 }
 
 test.describe("usage composer pill", () => {
+  test("shows the report when an existing running chat opens", async ({ page }) => {
+    test.setTimeout(180_000);
+    const usage = await installUsageReportsFixture(page, {
+      agentReportIds: [REPORT_ID],
+      lists: [[agentEntry(42)]],
+    });
+    const session = await seedRunningMockAgentWorkspace({
+      repoPrefix: "usage-running-",
+      title: "Running usage pill",
+      initialPrompt: "Show usage during the turn.",
+      model: "one-minute-stream",
+    });
+    try {
+      await openAgentRoute(page, session);
+      await expectComposerVisible(page);
+      await expect(page.getByTestId("usage-composer-pill")).toContainText("42%", {
+        timeout: 20_000,
+      });
+      expect(usage.agentRequests()[0]).toEqual({ agentId: session.agentId });
+    } finally {
+      await session.cleanup();
+    }
+  });
+
   test("opens the cached report without a request and shows when it was fetched", async ({
     page,
   }) => {
diff --git a/packages/app/src/usage/queries.ts b/packages/app/src/usage/queries.ts
index a7a717b627..3c3a6b7f9a 100644
--- a/packages/app/src/usage/queries.ts
+++ b/packages/app/src/usage/queries.ts
@@ -31,8 +31,13 @@ function usageReportsQueryKey(serverId: string) {
   return ["usage", "reports", serverId] as const;
 }
 
-function agentUsageQueryKey(serverId: string, agentId: string, model: string | null) {
-  return ["usage", "agent", serverId, agentId, model] as const;
+function agentUsageQueryKey(
+  serverId: string,
+  agentId: string,
+  model: string | null,
+  isRunning: boolean,
+) {
+  return ["usage", "agent", serverId, agentId, model, isRunning] as const;
 }
 
 function requireClient(serverId: string) {
@@ -160,8 +165,7 @@ export function useUsageByHost(): {
 /**
  * The usage report for the account an agent is spending. The daemon resolves the
  * report ID, which is re-resolved when the model changes (a new key) and when a
- * turn completes (the query is paused while the agent runs, and its data is always
- * stale, so resuming refetches). The report itself is read from the shared cache.
+ * turn completes (a new query key). The report itself is read from the shared cache.
  */
 export function useAgentUsage(
   serverId: string,
@@ -176,10 +180,10 @@ export function useAgentUsage(
     }),
   );
   const identity = useFetchQuery({
-    queryKey: agentUsageQueryKey(serverId, agentId, model),
+    queryKey: agentUsageQueryKey(serverId, agentId, model, isRunning),
     queryFn: async () =>
       (await requireClient(serverId).resolveAgentUsageReport({ agentId })).reportId,
-    enabled: isConnected && isSupported && !isRunning,
+    enabled: isConnected && isSupported,
     dataShape: "value",
     staleTimeMs: 0,
   });
diff --git a/packages/server/src/server/agent/agent-manager.ts b/packages/server/src/server/agent/agent-manager.ts
index 87d3b290aa..a4b3543075 100644
--- a/packages/server/src/server/agent/agent-manager.ts
+++ b/packages/server/src/server/agent/agent-manager.ts
@@ -50,6 +50,7 @@ import {
   type AgentTimelineItem,
   type AgentUsage,
   type AgentRuntimeInfo,
+  type UsageReference,
   type ImportedTimelineEntry,
   type ImportableProviderSession,
   type ListImportableSessionsOptions,
@@ -1167,6 +1168,22 @@ export class AgentManager {
     return agent ? { ...agent } : null;
   }
 
+  async resolveUsageReference(
+    id: string,
+  ): Promise<{ found: boolean; reference: UsageReference | null }> {
+    const agent = this.getAgent(id);
+    const stored = agent ? null : await this.registry?.get(id);
+    if (!agent && !stored) return { found: false, reference: null };
+    const provider = agent?.provider ?? stored!.provider;
+    const config = agent?.config ?? buildStoredAgentConfig(stored!);
+    const reference =
+      (await this.clients.get(provider)?.resolveUsageReference?.({
+        config,
+        session: agent?.session ?? null,
+      })) ?? null;
+    return { found: true, reference };
+  }
+
   async waitForAgentClose(agentId: string): Promise<void> {
     // Loading during reload must wait for the replacement, not resume another writer.
     await this.lifecycleMutationTails.get(agentId);
diff --git a/packages/server/src/server/agent/agent-sdk-types.ts b/packages/server/src/server/agent/agent-sdk-types.ts
index d42d98aaf7..11207836ad 100644
--- a/packages/server/src/server/agent/agent-sdk-types.ts
+++ b/packages/server/src/server/agent/agent-sdk-types.ts
@@ -673,8 +673,6 @@ 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<UsageReference | null>;
   run(prompt: AgentPromptInput, options?: AgentRunOptions): Promise<AgentRunResult>;
   startTurn(prompt: AgentPromptInput, options?: AgentRunOptions): Promise<{ turnId: string }>;
   steerActiveTurn?(prompt: AgentPromptInput, options: SteerActiveTurnOptions): Promise<SteerResult>;
@@ -750,6 +748,11 @@ export interface ResolveAgentDefaultModeInput {
 export interface AgentClient {
   readonly provider: AgentProvider;
   readonly capabilities: AgentCapabilityFlags;
+  /** Account used by the agent. Resolving this must not start or load a session. */
+  resolveUsageReference?(input: {
+    config: AgentSessionConfig;
+    session: AgentSession | null;
+  }): Promise<UsageReference | null>;
   createSession(
     config: AgentSessionConfig,
     launchContext?: AgentLaunchContext,
diff --git a/packages/server/src/server/agent/plugin-provider.test.ts b/packages/server/src/server/agent/plugin-provider.test.ts
index 8774b8784c..e1be6b8c8b 100644
--- a/packages/server/src/server/agent/plugin-provider.test.ts
+++ b/packages/server/src/server/agent/plugin-provider.test.ts
@@ -406,7 +406,12 @@ describe("PluginAgentClientRegistry", () => {
       cwd: "/workspace",
     });
     try {
-      expect(await session.getUsageReference?.()).toBeNull();
+      expect(
+        await client.resolveUsageReference?.({
+          config: { provider: harness.registration.id, cwd: "/workspace" },
+          session,
+        }),
+      ).toBeNull();
       expect(harness.inputs.some((input) => input.type === "session.usage_reference")).toBe(false);
     } finally {
       await session.close();
diff --git a/packages/server/src/server/agent/plugin-provider.ts b/packages/server/src/server/agent/plugin-provider.ts
index e6712d3c3b..1ba6bcce47 100644
--- a/packages/server/src/server/agent/plugin-provider.ts
+++ b/packages/server/src/server/agent/plugin-provider.ts
@@ -897,6 +897,15 @@ class PluginAgentClient implements AgentClient {
     return agentCapabilities(this.runtime.negotiatedCapabilities);
   }
 
+  async resolveUsageReference({
+    session,
+  }: {
+    config: AgentSessionConfig;
+    session: AgentSession | null;
+  }) {
+    return session instanceof PluginAgentSession ? session.getPluginUsageReference() : null;
+  }
+
   async createSession(
     config: AgentSessionConfig,
     launchContext?: AgentLaunchContext,
@@ -1096,7 +1105,7 @@ class PluginAgentSession implements AgentSession {
     return agentCapabilities(this.bridge.negotiatedCapabilities);
   }
 
-  getUsageReference(): Promise<UsageReference | null> {
+  getPluginUsageReference(): Promise<UsageReference | null> {
     return this.bridge.getUsageReference();
   }
 
diff --git a/packages/server/src/server/agent/provider-registry.ts b/packages/server/src/server/agent/provider-registry.ts
index 50ad1ae94d..38c4c24621 100644
--- a/packages/server/src/server/agent/provider-registry.ts
+++ b/packages/server/src/server/agent/provider-registry.ts
@@ -458,7 +458,6 @@ export function wrapSessionProvider(provider: AgentProvider, inner: AgentSession
       }
     },
     getRuntimeInfo: async () => mapRuntimeInfo(provider, await inner.getRuntimeInfo()),
-    getUsageReference: inner.getUsageReference?.bind(inner),
     getAvailableModes: () => inner.getAvailableModes(),
     getCurrentMode: () => inner.getCurrentMode(),
     setMode: (modeId) => inner.setMode(modeId),
@@ -490,13 +489,25 @@ function wrapClientProvider(
   const listFeatures = inner.listFeatures?.bind(inner);
   const archiveNativeSession = inner.archiveNativeSession?.bind(inner);
   const unarchiveNativeSession = inner.unarchiveNativeSession?.bind(inner);
+  const sessions = new WeakMap<AgentSession, AgentSession>();
+  const wrapSession = (session: AgentSession) => {
+    const wrapped = wrapSessionProvider(provider, session);
+    sessions.set(wrapped, session);
+    return wrapped;
+  };
 
   return {
     provider,
     capabilities: inner.capabilities,
+    resolveUsageReference: inner.resolveUsageReference
+      ? ({ config, session }) =>
+          inner.resolveUsageReference!({
+            config: { ...config, provider: inner.provider },
+            session: session ? (sessions.get(session) ?? null) : null,
+          })
+      : undefined,
     createSession: async (config, launchContext) =>
-      wrapSessionProvider(
-        provider,
+      wrapSession(
         await inner.createSession(
           {
             ...config,
@@ -506,8 +517,7 @@ function wrapClientProvider(
         ),
       ),
     resumeSession: async (handle, overrides, launchContext, options) =>
-      wrapSessionProvider(
-        provider,
+      wrapSession(
         await inner.resumeSession(
           {
             ...handle,
@@ -569,7 +579,7 @@ function wrapClientProvider(
           }
           return {
             ...imported,
-            session: wrapSessionProvider(provider, imported.session),
+            session: wrapSession(imported.session),
             config: {
               ...imported.config,
               provider,
diff --git a/packages/server/src/server/agent/providers/acp-agent.test.ts b/packages/server/src/server/agent/providers/acp-agent.test.ts
index 0394900d3b..f39d8e723e 100644
--- a/packages/server/src/server/agent/providers/acp-agent.test.ts
+++ b/packages/server/src/server/agent/providers/acp-agent.test.ts
@@ -224,8 +224,17 @@ 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: {} });
+    const client = new ACPAgentClient({
+      provider,
+      logger: createTestLogger(),
+      defaultCommand: ["unused"],
+    });
+    expect(
+      await client.resolveUsageReference({
+        config: { provider, cwd: "/tmp/paseo-acp-test" },
+        session: null,
+      }),
+    ).toEqual({ source: provider, input: {} });
   }
 });
 
diff --git a/packages/server/src/server/agent/providers/acp-agent.ts b/packages/server/src/server/agent/providers/acp-agent.ts
index 019725ce3f..acad3df87a 100644
--- a/packages/server/src/server/agent/providers/acp-agent.ts
+++ b/packages/server/src/server/agent/providers/acp-agent.ts
@@ -882,6 +882,9 @@ function isACPCreateConfigUnattended(input: AgentCreateConfigUnattendedInput): b
 export class ACPAgentClient implements AgentClient {
   readonly provider: string;
   readonly capabilities: AgentCapabilityFlags;
+  async resolveUsageReference() {
+    return { source: this.provider, input: {} };
+  }
   readonly resolveCreateConfig = resolveACPCreateConfig;
   readonly isCreateConfigUnattended = isACPCreateConfigUnattended;
 
@@ -1633,10 +1636,6 @@ 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[]];
diff --git a/packages/server/src/server/agent/providers/claude/agent.test.ts b/packages/server/src/server/agent/providers/claude/agent.test.ts
index 16aa193cce..f148f53101 100644
--- a/packages/server/src/server/agent/providers/claude/agent.test.ts
+++ b/packages/server/src/server/agent/providers/claude/agent.test.ts
@@ -531,16 +531,16 @@ 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({
+    const config = { provider: "claude", cwd: process.cwd() };
+    const client = new ClaudeAgentClient({
+      logger,
+      runtimeSettings: { env: { CLAUDE_CONFIG_DIR: "/accounts/second" } },
+      resolveBinary: async () => "/test/claude/bin",
+    });
+    expect(await client.resolveUsageReference?.({ config, session: null })).toEqual({
       source: "claude",
       input: { configDir: "/accounts/second" },
     });
-    await session.close();
   });
 
   test.each(["ANTHROPIC_BASE_URL", "ANTHROPIC_API_KEY", "ANTHROPIC_AUTH_TOKEN"])(
@@ -548,14 +548,15 @@ describe("ClaudeAgentClient binary resolution", () => {
     async (name) => {
       const client = new ClaudeAgentClient({
         logger,
+        runtimeSettings: { env: { [name]: "override" } },
         resolveBinary: async () => "/test/claude/bin",
       });
-      const session = await client.createSession(
-        { provider: "claude", cwd: process.cwd() },
-        { env: { [name]: "override" } },
-      );
-      expect(await session.getUsageReference?.()).toBeNull();
-      await session.close();
+      expect(
+        await client.resolveUsageReference?.({
+          config: { provider: "claude", cwd: process.cwd() },
+          session: null,
+        }),
+      ).toBeNull();
     },
   );
 
@@ -569,15 +570,16 @@ describe("ClaudeAgentClient binary resolution", () => {
         },
       },
     });
-    const session = await registry["work-claude"].createClient(logger).createSession({
-      provider: "work-claude",
-      cwd: process.cwd(),
-    });
-    expect(await session.getUsageReference?.()).toEqual({
+    const client = registry["work-claude"].createClient(logger);
+    expect(
+      await client.resolveUsageReference?.({
+        config: { provider: "work-claude", cwd: process.cwd() },
+        session: null,
+      }),
+    ).toEqual({
       source: "claude",
       input: { configDir: "/accounts/work" },
     });
-    await session.close();
   });
 
   test("resolves the installed Claude Code version", async () => {
diff --git a/packages/server/src/server/agent/providers/claude/agent.ts b/packages/server/src/server/agent/providers/claude/agent.ts
index 38476490b3..8fdae8722e 100644
--- a/packages/server/src/server/agent/providers/claude/agent.ts
+++ b/packages/server/src/server/agent/providers/claude/agent.ts
@@ -1519,6 +1519,15 @@ export class ClaudeAgentClient implements AgentClient {
     this.rewindSdk = options.rewindSdk ?? realClaudeRewindSdk;
   }
 
+  async resolveUsageReference() {
+    const env = createProviderEnv({ baseEnv: process.env, runtimeSettings: this.runtimeSettings });
+    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") },
+    };
+  }
+
   resolveConfiguredModel(model: AgentModelDefinition): AgentModelDefinition {
     return resolveConfiguredClaudeModel(model);
   }
@@ -2042,15 +2051,6 @@ 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;
diff --git a/packages/server/src/server/agent/providers/codex-app-server-agent.test.ts b/packages/server/src/server/agent/providers/codex-app-server-agent.test.ts
index d4a96b45e6..26f1227657 100644
--- a/packages/server/src/server/agent/providers/codex-app-server-agent.test.ts
+++ b/packages/server/src/server/agent/providers/codex-app-server-agent.test.ts
@@ -172,41 +172,18 @@ function createSession(
 }
 
 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({
+  const config = createConfig();
+  const client = new CodexAppServerAgentClient(createTestLogger(), {
+    env: { CODEX_HOME: "/accounts/second" },
+  });
+  expect(await client.resolveUsageReference({ config, session: null })).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();
+  const custom = new CodexAppServerAgentClient(createTestLogger(), {
+    env: { CODEX_HOME: "/accounts/second", OPENAI_BASE_URL: "https://example.test" },
+  });
+  expect(await custom.resolveUsageReference({ config, session: null })).toBeNull();
 });
 
 function createProviderWithFakeAppServer(
diff --git a/packages/server/src/server/agent/providers/codex-app-server-agent.ts b/packages/server/src/server/agent/providers/codex-app-server-agent.ts
index 55d7886df8..a52706e1ae 100644
--- a/packages/server/src/server/agent/providers/codex-app-server-agent.ts
+++ b/packages/server/src/server/agent/providers/codex-app-server-agent.ts
@@ -3456,7 +3456,6 @@ 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",
@@ -3486,17 +3485,6 @@ 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;
   }
@@ -7040,6 +7028,15 @@ export class CodexAppServerAgentClient implements AgentClient {
     private readonly deps: CodexAppServerAgentDeps = {},
   ) {}
 
+  async resolveUsageReference() {
+    const env = buildCodexAppServerEnv(this.runtimeSettings);
+    if (env.OPENAI_BASE_URL) return null;
+    return {
+      source: "codex",
+      input: { codexHome: env.CODEX_HOME || path.join(env.HOME || os.homedir(), ".codex") },
+    };
+  }
+
   private sessionDeps(launchEnv: Record<string, string> | undefined): CodexAppServerAgentDeps {
     return {
       ...this.deps,
@@ -7161,7 +7158,6 @@ export class CodexAppServerAgentClient implements AgentClient {
       autoReviewEnabled,
       launchContext?.agentId,
       "interactive",
-      buildCodexAppServerEnv(this.runtimeSettings, launchContext?.env),
     );
     await session.connect();
     return session;
@@ -7194,7 +7190,6 @@ export class CodexAppServerAgentClient implements AgentClient {
       autoReviewEnabled,
       launchContext?.agentId,
       options?.purpose ?? "interactive",
-      buildCodexAppServerEnv(this.runtimeSettings, launchContext?.env),
     );
     await session.connect();
     return session;
diff --git a/packages/server/src/server/agent/providers/omp/agent.ts b/packages/server/src/server/agent/providers/omp/agent.ts
index 5555fa130e..aab87ddea6 100644
--- a/packages/server/src/server/agent/providers/omp/agent.ts
+++ b/packages/server/src/server/agent/providers/omp/agent.ts
@@ -969,9 +969,13 @@ export class OmpAgentSession implements AgentSession {
   private readonly paseoTools?: PaseoToolCatalog;
   private readonly usageEnv: NodeJS.ProcessEnv;
 
-  async getUsageReference() {
+  async getUsageContext() {
     const state = await this.runtimeSession.getState();
-    return resolveOmpUsageReference(state.sessionId, state.model?.provider ?? "", this.usageEnv);
+    return {
+      sessionId: state.sessionId,
+      provider: state.model?.provider ?? "",
+      env: this.usageEnv,
+    };
   }
 
   get id(): string | null {
@@ -2274,6 +2278,18 @@ export class OmpAgentClient implements AgentClient {
       options.runtime ?? createRuntime(options.logger, runtimeSettings, this.providerParams);
   }
 
+  async resolveUsageReference({
+    session,
+  }: {
+    config: AgentSessionConfig;
+    session: AgentSession | null;
+  }) {
+    // OMP's credential lookup needs the runtime session ID, which stored config does not contain.
+    if (!(session instanceof OmpAgentSession)) return null;
+    const { sessionId, provider, env } = await session.getUsageContext();
+    return resolveOmpUsageReference(sessionId, provider, env);
+  }
+
   private async configureNativePaseoTools(
     runtimeSession: OmpRuntimeSession,
     catalog: PaseoToolCatalog | undefined,
diff --git a/packages/server/src/server/agent/providers/omp/test-utils/omp-harness.ts b/packages/server/src/server/agent/providers/omp/test-utils/omp-harness.ts
index 7c99fa772c..0390a5905f 100644
--- a/packages/server/src/server/agent/providers/omp/test-utils/omp-harness.ts
+++ b/packages/server/src/server/agent/providers/omp/test-utils/omp-harness.ts
@@ -484,7 +484,10 @@ export class OmpHarness {
   }
 
   async getUsageReference() {
-    return this.requireSession().getUsageReference();
+    return this.client.resolveUsageReference({
+      config: { provider: "omp", cwd: CWD },
+      session: this.requireSession(),
+    });
   }
 
   runningToolCallIds(): string[] {
diff --git a/packages/server/src/server/agent/providers/opencode-agent.test.ts b/packages/server/src/server/agent/providers/opencode-agent.test.ts
index 0634ec25cb..191a87c160 100644
--- a/packages/server/src/server/agent/providers/opencode-agent.test.ts
+++ b/packages/server/src/server/agent/providers/opencode-agent.test.ts
@@ -420,19 +420,28 @@ describe("OpenCodeAgentClient adapter smoke tests", () => {
       },
       { serverManager: runtime, createClient: runtime.createClient },
     );
+    expect(
+      await client.resolveUsageReference({
+        config: { ...buildConfig(cwd), model: "openai/gpt-5" },
+        session: null,
+      }),
+    ).toEqual({
+      source: "codex",
+      input: { accessToken: "oauth-token", accountId: "acct-1" },
+    });
     const session = await client.createSession(buildConfig(cwd));
     await session.setModel?.("openai/gpt-5");
-    expect(await session.getUsageReference?.()).toEqual({
+    expect(await client.resolveUsageReference({ config: buildConfig(cwd), session })).toEqual({
       source: "codex",
       input: { accessToken: "oauth-token", accountId: "acct-1" },
     });
     await session.setModel?.("opencode-go/qwen");
-    expect(await session.getUsageReference?.()).toEqual({
+    expect(await client.resolveUsageReference({ config: buildConfig(cwd), session })).toEqual({
       source: "opencode-go",
       input: { apiKey: "go-key" },
     });
     await session.setModel?.("other/model");
-    expect(await session.getUsageReference?.()).toBeNull();
+    expect(await client.resolveUsageReference({ config: buildConfig(cwd), session })).toBeNull();
     const events: AgentStreamEvent[] = [];
     session.subscribe((event) => events.push(event));
     const sessionId = (await session.getRuntimeInfo()).sessionId;
@@ -448,7 +457,7 @@ describe("OpenCodeAgentClient adapter smoke tests", () => {
       },
     } as OpenCodeEvent);
     await vi.waitFor(async () =>
-      expect(await session.getUsageReference?.()).toEqual({
+      expect(await client.resolveUsageReference({ config: buildConfig(cwd), session })).toEqual({
         source: "codex",
         input: { accessToken: "oauth-token", accountId: "acct-1" },
       }),
@@ -487,7 +496,7 @@ describe("OpenCodeAgentClient adapter smoke tests", () => {
     const session = await client.createSession(buildConfig(cwd));
     try {
       await session.setModel?.("opencode-go/qwen");
-      expect(await session.getUsageReference?.()).toEqual({
+      expect(await client.resolveUsageReference({ config: buildConfig(cwd), session })).toEqual({
         source: "opencode-go",
         input: { apiKey: "go-key" },
       });
diff --git a/packages/server/src/server/agent/providers/opencode-agent.ts b/packages/server/src/server/agent/providers/opencode-agent.ts
index b2cab99c6e..1bbb908f2d 100644
--- a/packages/server/src/server/agent/providers/opencode-agent.ts
+++ b/packages/server/src/server/agent/providers/opencode-agent.ts
@@ -1445,6 +1445,22 @@ export class OpenCodeAgentClient implements AgentClient {
     this.resolveHomeDir = deps.resolveHomeDir ?? resolveOpenCodeHomeDir;
   }
 
+  async resolveUsageReference({
+    config,
+    session,
+  }: {
+    config: AgentSessionConfig;
+    session: AgentSession | null;
+  }): Promise<UsageReference | null> {
+    const model = session ? (await session.getRuntimeInfo()).model : config.model;
+    if (!model?.startsWith("openai/") && !model?.startsWith("opencode-go/")) return null;
+    const env =
+      session instanceof OpenCodeAgentSession
+        ? session.getUsageEnvironment()
+        : { ...process.env, ...this.runtimeSettings?.env };
+    return resolveOpenCodeUsageReference(model, await readOpenCodeUsageAuth(env));
+  }
+
   async createSession(
     config: AgentSessionConfig,
     launchContext?: AgentLaunchContext,
@@ -3620,11 +3636,8 @@ class OpenCodeAgentSession implements AgentSession {
     };
   }
 
-  async getUsageReference(): Promise<UsageReference | 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);
+  getUsageEnvironment(): NodeJS.ProcessEnv {
+    return this.usageEnv;
   }
 
   async setModel(modelId: string | null): Promise<void> {
diff --git a/packages/server/src/server/agent/providers/pi/agent.test.ts b/packages/server/src/server/agent/providers/pi/agent.test.ts
index 7308185db0..99770c16e9 100644
--- a/packages/server/src/server/agent/providers/pi/agent.test.ts
+++ b/packages/server/src/server/agent/providers/pi/agent.test.ts
@@ -229,15 +229,16 @@ test("Pi usage reference follows the current OAuth model and agent directory", a
       runtime = sessionRuntime;
       runtime.state.model = { provider: "openai-codex", id: "gpt", name: "GPT" };
     });
-    const session = await createClient(pi).createSession(createConfig(), {
+    const client = createClient(pi);
+    const session = await client.createSession(createConfig(), {
       env: { PI_CODING_AGENT_DIR: agentDir },
     });
-    expect(await session.getUsageReference?.()).toEqual({
+    expect(await client.resolveUsageReference({ config: createConfig(), session })).toEqual({
       source: "codex",
       input: { accessToken: "codex-token", accountId: "account-1" },
     });
     runtime.state.model = { provider: "anthropic", id: "claude", name: "Claude" };
-    expect(await session.getUsageReference?.()).toEqual({
+    expect(await client.resolveUsageReference({ config: createConfig(), session })).toEqual({
       source: "claude",
       input: { accessToken: "claude-token" },
     });
@@ -249,7 +250,7 @@ test("Pi usage reference follows the current OAuth model and agent directory", a
       }),
     );
     runtime.state.model = { provider: "openai-codex", id: "gpt", name: "GPT" };
-    expect(await session.getUsageReference?.()).toEqual({
+    expect(await client.resolveUsageReference({ config: createConfig(), session })).toEqual({
       source: "codex",
       input: { accessToken: "codex-token" },
     });
@@ -258,15 +259,38 @@ test("Pi usage reference follows the current OAuth model and agent directory", a
       path.join(agentDir, "auth.json"),
       JSON.stringify({ anthropic: { type: "api_key", key: "api-key" } }),
     );
-    expect(await session.getUsageReference?.()).toBeNull();
+    expect(await client.resolveUsageReference({ config: createConfig(), session })).toBeNull();
     runtime.state.model = { provider: "other", id: "other", name: "Other" };
-    expect(await session.getUsageReference?.()).toBeNull();
+    expect(await client.resolveUsageReference({ config: createConfig(), session })).toBeNull();
     await session.close();
   } finally {
     rmSync(agentDir, { recursive: true, force: true });
   }
 });
 
+test("Pi resolves a stored model without opening a session", async () => {
+  const agentDir = mkdtempSync(path.join(tmpdir(), "paseo-pi-stored-usage-"));
+  try {
+    writeFileSync(
+      path.join(agentDir, "auth.json"),
+      JSON.stringify({ anthropic: { type: "oauth", access: "claude-token", refresh: "refresh" } }),
+    );
+    const client = new PiRpcAgentClient({
+      logger: pino({ level: "silent" }),
+      runtime: new FakePi(),
+      runtimeSettings: { env: { PI_CODING_AGENT_DIR: agentDir } },
+    });
+    expect(
+      await client.resolveUsageReference({
+        config: createConfig({ model: "anthropic/claude-sonnet-4" }),
+        session: null,
+      }),
+    ).toEqual({ source: "claude", input: { accessToken: "claude-token" } });
+  } 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);
diff --git a/packages/server/src/server/agent/providers/pi/agent.ts b/packages/server/src/server/agent/providers/pi/agent.ts
index 5d7966367e..4ccab930ba 100644
--- a/packages/server/src/server/agent/providers/pi/agent.ts
+++ b/packages/server/src/server/agent/providers/pi/agent.ts
@@ -1141,37 +1141,40 @@ function createRuntime(
   });
 }
 
+async function resolvePiUsageReference(provider: string | undefined, env?: Record<string, string>) {
+  let source: string | null = null;
+  if (provider === "openai-codex") source = "codex";
+  if (provider === "anthropic") source = "claude";
+  if (!source || !provider) return null;
+  try {
+    const auth: unknown = JSON.parse(
+      await readFile(join(resolvePiAgentDir(env), "auth.json"), "utf8"),
+    );
+    if (provider === "openai-codex") {
+      const credential = piCodexUsageAuthSchema.parse(auth)["openai-codex"];
+      if (!credential) return null;
+      return {
+        source,
+        input: {
+          accessToken: credential.access,
+          ...(credential.accountId ? { accountId: credential.accountId } : {}),
+        },
+      };
+    }
+    const credential = piClaudeUsageAuthSchema.parse(auth).anthropic;
+    return credential ? { source, input: { accessToken: credential.access } } : null;
+  } catch {
+    return null;
+  }
+}
+
 export class PiRpcAgentSession implements AgentSession {
   readonly provider: AgentProvider;
   readonly capabilities: AgentCapabilityFlags;
 
-  async getUsageReference() {
+  async getUsageContext() {
     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 auth: unknown = JSON.parse(
-        await readFile(join(resolvePiAgentDir(this.usageEnv), "auth.json"), "utf8"),
-      );
-      if (provider === "openai-codex") {
-        const credential = piCodexUsageAuthSchema.parse(auth)["openai-codex"];
-        if (!credential) return null;
-        return {
-          source,
-          input: {
-            accessToken: credential.access,
-            ...(credential.accountId ? { accountId: credential.accountId } : {}),
-          },
-        };
-      }
-      const credential = piClaudeUsageAuthSchema.parse(auth).anthropic;
-      return credential ? { source, input: { accessToken: credential.access } } : null;
-    } catch {
-      return null;
-    }
+    return { provider: this.state.model?.provider, env: this.usageEnv };
   }
 
   private readonly subscribers = new Set<(event: AgentStreamEvent) => void>();
@@ -2477,6 +2480,18 @@ export class PiRpcAgentClient implements AgentClient {
     this.usagePollScheduler = options.usagePollScheduler;
   }
 
+  async resolveUsageReference({
+    config,
+    session,
+  }: {
+    config: AgentSessionConfig;
+    session: AgentSession | null;
+  }) {
+    const context = session instanceof PiRpcAgentSession ? await session.getUsageContext() : null;
+    const provider = context?.provider ?? config.model?.split("/")[0];
+    return resolvePiUsageReference(provider, context?.env ?? this.runtimeSettings?.env);
+  }
+
   async createSession(
     config: AgentSessionConfig,
     launchContext?: AgentLaunchContext,
diff --git a/packages/server/src/server/plugins/session-usage-reference.e2e.test.ts b/packages/server/src/server/plugins/session-usage-reference.e2e.test.ts
index c4f2287bbf..1d7c7a47f3 100644
--- a/packages/server/src/server/plugins/session-usage-reference.e2e.test.ts
+++ b/packages/server/src/server/plugins/session-usage-reference.e2e.test.ts
@@ -1,10 +1,8 @@
 import { fileURLToPath } from "node:url";
+import { mkdtemp, rm } from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
 import { expect, test } from "vitest";
-import { ACPAgentSession } from "../agent/providers/acp-agent.js";
-import type { UsageReference } from "../agent/agent-sdk-types.js";
-import { ClaudeAgentClient } from "../agent/providers/claude/agent.js";
-import { CodexAppServerAgentSession } from "../agent/providers/codex-app-server-agent.js";
-import { createTestLogger } from "../../test-utils/test-logger.js";
 import { DaemonClient } from "../test-utils/daemon-client.js";
 import { createTestAgentClient } from "../test-utils/fake-agent-client.js";
 import { createTestPaseoDaemon } from "../test-utils/paseo-daemon.js";
@@ -53,75 +51,21 @@ test("resolves a provider plugin session reference through its usage source", as
   }
 }, 60_000);
 
-test("agent.resolve_usage_report resolves source IDs from default built-in and ACP sessions", async () => {
+test("agent.resolve_usage_report resolves source IDs from provider clients", async () => {
   const directory = fileURLToPath(
     new URL("./test-fixtures/session-usage-reference/", import.meta.url),
   );
   const providers = ["claude", "codex", "copilot", "cursor", "kimi", "generic-acp"] as const;
-  const logger = createTestLogger();
-  const references = new Map<string, UsageReference | null>();
-  const claude = await new ClaudeAgentClient({
-    logger,
-    resolveBinary: async () => "/test/claude/bin",
-  }).createSession(
-    { provider: "claude", cwd: directory },
-    {
-      env: {
-        HOME: directory,
-        CLAUDE_CONFIG_DIR: "",
-        ANTHROPIC_BASE_URL: "",
-        ANTHROPIC_API_KEY: "",
-        ANTHROPIC_AUTH_TOKEN: "",
-      },
-    },
-  );
-  references.set("claude", (await claude.getUsageReference?.()) ?? null);
-  await claude.close();
-  const codex = new CodexAppServerAgentSession(
-    { provider: "codex", cwd: directory },
-    null,
-    logger,
-    () => {
-      throw new Error("Codex runtime should not start");
-    },
-    {},
-    false,
-    false,
-    false,
-    undefined,
-    "interactive",
-    { HOME: directory, OPENAI_BASE_URL: "" },
-  );
-  references.set("codex", await codex.getUsageReference());
-  for (const provider of providers.slice(2)) {
-    const session = new ACPAgentSession(
-      { provider, cwd: directory },
-      {
-        provider,
-        logger,
-        defaultCommand: ["unused"],
-        defaultModes: [],
-        capabilities: {
-          supportsStreaming: true,
-          supportsSessionPersistence: true,
-          supportsDynamicModes: true,
-          supportsMcpServers: true,
-          supportsReasoningStream: true,
-          supportsToolInvocations: true,
-        },
-      },
-    );
-    references.set(provider, await session.getUsageReference());
-  }
   const agentClients = Object.fromEntries(
     providers.map((provider) => {
       const client = createTestAgentClient(provider);
-      const createSession = client.createSession.bind(client);
-      client.createSession = async (...args) => {
-        const session = await createSession(...args);
-        session.getUsageReference = async () => references.get(provider) ?? null;
-        return session;
-      };
+      let input: Record<string, string> = {};
+      if (provider === "claude") input = { configDir: directory };
+      if (provider === "codex") input = { codexHome: directory };
+      client.resolveUsageReference = async () => ({
+        source: provider,
+        input,
+      });
       return [provider, client];
     }),
   );
@@ -148,3 +92,64 @@ test("agent.resolve_usage_report resolves source IDs from default built-in and A
     await daemon.close();
   }
 }, 60_000);
+
+test("stored Claude and Codex agents resolve without opening a provider session", async () => {
+  const root = await mkdtemp(path.join(os.tmpdir(), "paseo-usage-closed-"));
+  const staticDir = await mkdtemp(path.join(os.tmpdir(), "paseo-usage-static-"));
+  const sessionsOpened = new Map<string, number>();
+  const agentClients = Object.fromEntries(
+    ["claude", "codex"].map((provider) => {
+      const providerClient = createTestAgentClient(provider, {
+        beforeCreateSession: async () => {
+          sessionsOpened.set(provider, (sessionsOpened.get(provider) ?? 0) + 1);
+        },
+      });
+      providerClient.resolveUsageReference = async ({ session }) => {
+        expect(session).toBeNull();
+        return { source: "fixture-session-usage", input: { account: "from-session" } };
+      };
+      return [provider, providerClient];
+    }),
+  );
+  const options = {
+    paseoHomeRoot: root,
+    staticDir,
+    cleanup: false,
+    pluginsEnabled: false,
+    builtinPlugins: fixtureBuiltins(),
+    agentClients,
+  };
+  let daemon = await createTestPaseoDaemon(options);
+  let client = new DaemonClient({ url: `ws://127.0.0.1:${daemon.port}/ws` });
+  try {
+    await client.connect();
+    const ids: string[] = [];
+    for (const provider of ["claude", "codex"]) {
+      const agent = await client.createAgent({ provider, cwd: root });
+      ids.push(agent.id);
+      await client.sendMessage(agent.id, "Say OK.");
+      await client.waitForAgentUpsert(agent.id, (snapshot) => snapshot.status === "idle");
+      expect(sessionsOpened.get(provider)).toBe(1);
+    }
+    await client.close();
+    await daemon.close();
+
+    daemon = await createTestPaseoDaemon(options);
+    client = new DaemonClient({ url: `ws://127.0.0.1:${daemon.port}/ws` });
+    await client.connect();
+    await client.fetchAgents({ subscribe: {} });
+    for (const [index, provider] of ["claude", "codex"].entries()) {
+      const result = await client.resolveAgentUsageReport({ agentId: ids[index]! });
+      expect(result.reportId).toBe("fixture-session-usage:from-session");
+      expect(
+        (await client.listUsageReports({ reportIds: [result.reportId!] })).reports,
+      ).toHaveLength(1);
+      expect(sessionsOpened.get(provider)).toBe(1);
+    }
+  } finally {
+    await client.close().catch(() => undefined);
+    await daemon.close().catch(() => undefined);
+    await rm(root, { recursive: true, force: true });
+    await rm(staticDir, { recursive: true, force: true });
+  }
+}, 60_000);
diff --git a/packages/server/src/server/session.ts b/packages/server/src/server/session.ts
index f83040c8c9..f2365b54ff 100644
--- a/packages/server/src/server/session.ts
+++ b/packages/server/src/server/session.ts
@@ -1000,7 +1000,7 @@ export class Session {
     this.usageSession = new UsageSession({
       emit: (msg) => this.emit(msg),
       listAgents: () => this.agentManager.listAgents(),
-      getAgent: (agentId) => this.agentManager.getAgent(agentId),
+      resolveAgentReference: (agentId) => this.agentManager.resolveUsageReference(agentId),
       runtime: pluginRuntime,
       logger: this.sessionLogger,
     });
diff --git a/packages/server/src/server/session/usage/usage-session.test.ts b/packages/server/src/server/session/usage/usage-session.test.ts
index 7914af3872..578747333a 100644
--- a/packages/server/src/server/session/usage/usage-session.test.ts
+++ b/packages/server/src/server/session/usage/usage-session.test.ts
@@ -1,6 +1,5 @@
 import pino from "pino";
 import { expect, test } from "vitest";
-import type { AgentSession } from "../../agent/agent-sdk-types.js";
 import type { SessionOutboundMessage } from "../../messages.js";
 import { UsageSession } from "./usage-session.js";
 
@@ -9,9 +8,8 @@ test("collects live references for usage reports and resolves an agent report",
   const references: unknown[] = [];
   const reference = { source: "fixture", input: { account: "one" } };
   const agent = {
-    session: {
-      getUsageReference: async () => reference,
-    } as AgentSession,
+    id: "one",
+    session: {},
   };
   const entry = {
     id: "fixture:one",
@@ -23,8 +21,8 @@ test("collects live references for usage reports and resolves an agent report",
   };
   const usage = new UsageSession({
     emit: (message) => emitted.push(message),
-    listAgents: () => [agent, { session: null }],
-    getAgent: (id) => (id === "one" ? agent : null),
+    listAgents: () => [agent, { id: "closed", session: null }],
+    resolveAgentReference: async (id) => ({ found: id === "one", reference }),
     runtime: {
       async listUsageReports(options) {
         references.push(options.references);
@@ -59,7 +57,7 @@ test("surfaces a legacy usage-list failure as an rpc_error envelope", async () =
   const usage = new UsageSession({
     emit: (message) => emitted.push(message),
     listAgents: () => [],
-    getAgent: () => null,
+    resolveAgentReference: async () => ({ found: false, reference: null }),
     runtime: {
       async listUsageReports() {
         return [];
@@ -85,7 +83,7 @@ test("unknown agent returns agent_not_found", async () => {
   const usage = new UsageSession({
     emit: (message) => emitted.push(message),
     listAgents: () => [],
-    getAgent: () => null,
+    resolveAgentReference: async () => ({ found: false, reference: null }),
     runtime: {
       listUsageReports: async () => [],
       resolveUsageReference: async () => null,
diff --git a/packages/server/src/server/session/usage/usage-session.ts b/packages/server/src/server/session/usage/usage-session.ts
index 6665a7454f..21c8f99801 100644
--- a/packages/server/src/server/session/usage/usage-session.ts
+++ b/packages/server/src/server/session/usage/usage-session.ts
@@ -1,16 +1,20 @@
 import type pino from "pino";
 import type { ProviderUsage, UsageReportEntry } from "@getpaseo/protocol/messages";
-import type { AgentSession, UsageReference } from "../../agent/agent-sdk-types.js";
+import type { UsageReference } from "../../agent/agent-sdk-types.js";
 import type { SessionInboundMessage, SessionOutboundMessage } from "../../messages.js";
 
 interface UsageAgent {
-  session: AgentSession | null;
+  id: string;
+  session: object | null;
 }
 
 export interface UsageSessionOptions {
   emit(message: SessionOutboundMessage): void;
   listAgents(): UsageAgent[];
-  getAgent(agentId: string): UsageAgent | null;
+  resolveAgentReference(agentId: string): Promise<{
+    found: boolean;
+    reference: UsageReference | null;
+  }>;
   runtime?: {
     listUsageReports(options: {
       forceRefresh?: boolean;
@@ -37,8 +41,12 @@ export class UsageSession {
               await Promise.all(
                 this.options
                   .listAgents()
-                  .map(
-                    async (agent) => agent.session?.getUsageReference?.().catch(() => null) ?? null,
+                  .filter((agent) => agent.session !== null)
+                  .map(async (agent) =>
+                    this.options
+                      .resolveAgentReference(agent.id)
+                      .then((resolved) => resolved.reference)
+                      .catch(() => null),
                   ),
               )
             ).filter((reference): reference is UsageReference => reference !== null)
@@ -62,12 +70,12 @@ export class UsageSession {
   ): Promise<void> {
     try {
       if (!this.options.runtime) throw new Error("Plugin runtime is unavailable");
-      const agent = this.options.getAgent(msg.agentId);
-      if (!agent) {
+      const resolved = await this.options.resolveAgentReference(msg.agentId);
+      if (!resolved.found) {
         this.emitError(msg, new Error(`Agent not found: ${msg.agentId}`), "agent_not_found");
         return;
       }
-      const reference = (await agent.session?.getUsageReference?.()) ?? null;
+      const reference = resolved.reference;
       const reportId = reference
         ? await this.options.runtime.resolveUsageReference(reference)
         : null;