diff --git a/packages/adapter-utils/src/index.ts b/packages/adapter-utils/src/index.ts
index 6869c1ea..67e51dc6 100644
--- a/packages/adapter-utils/src/index.ts
+++ b/packages/adapter-utils/src/index.ts
@@ -5,6 +5,7 @@ export type {
   AdapterExecutionResult,
   AdapterInvocationMeta,
   AdapterExecutionContext,
+  AdapterSessionCodec,
   ServerAdapterModule,
   TranscriptEntry,
   StdoutLineParser,
diff --git a/packages/adapter-utils/src/types.ts b/packages/adapter-utils/src/types.ts
index d8253edd..80d6a52e 100644
--- a/packages/adapter-utils/src/types.ts
+++ b/packages/adapter-utils/src/types.ts
@@ -11,7 +11,13 @@ export interface AdapterAgent {
 }
 
 export interface AdapterRuntime {
+  /**
+   * Legacy single session id view. Prefer `sessionParams` + `sessionDisplayId`.
+   */
   sessionId: string | null;
+  sessionParams: Record<string, unknown> | null;
+  sessionDisplayId: string | null;
+  taskKey: string | null;
 }
 
 // ---------------------------------------------------------------------------
@@ -30,7 +36,12 @@ export interface AdapterExecutionResult {
   timedOut: boolean;
   errorMessage?: string | null;
   usage?: UsageSummary;
+  /**
+   * Legacy single session id output. Prefer `sessionParams` + `sessionDisplayId`.
+   */
   sessionId?: string | null;
+  sessionParams?: Record<string, unknown> | null;
+  sessionDisplayId?: string | null;
   provider?: string | null;
   model?: string | null;
   costUsd?: number | null;
@@ -39,6 +50,12 @@ export interface AdapterExecutionResult {
   clearSession?: boolean;
 }
 
+export interface AdapterSessionCodec {
+  deserialize(raw: unknown): Record<string, unknown> | null;
+  serialize(params: Record<string, unknown> | null): Record<string, unknown> | null;
+  getDisplayId?: (params: Record<string, unknown> | null) => string | null;
+}
+
 export interface AdapterInvocationMeta {
   adapterType: string;
   command: string;
@@ -63,6 +80,7 @@ export interface AdapterExecutionContext {
 export interface ServerAdapterModule {
   type: string;
   execute(ctx: AdapterExecutionContext): Promise<AdapterExecutionResult>;
+  sessionCodec?: AdapterSessionCodec;
   supportsLocalAgentJwt?: boolean;
   models?: { id: string; label: string }[];
   agentConfigurationDoc?: string;
diff --git a/packages/adapters/claude-local/src/server/execute.ts b/packages/adapters/claude-local/src/server/execute.ts
index d279fcfc..e3306694 100644
--- a/packages/adapters/claude-local/src/server/execute.ts
+++ b/packages/adapters/claude-local/src/server/execute.ts
@@ -119,7 +119,19 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
   })();
   const skillsDir = await buildSkillsDir();
 
-  const sessionId = runtime.sessionId;
+  const runtimeSessionParams = parseObject(runtime.sessionParams);
+  const runtimeSessionId = asString(runtimeSessionParams.sessionId, runtime.sessionId ?? "");
+  const runtimeSessionCwd = asString(runtimeSessionParams.cwd, "");
+  const canResumeSession =
+    runtimeSessionId.length > 0 &&
+    (runtimeSessionCwd.length === 0 || path.resolve(runtimeSessionCwd) === path.resolve(cwd));
+  const sessionId = canResumeSession ? runtimeSessionId : null;
+  if (runtimeSessionId && !canResumeSession) {
+    await onLog(
+      "stderr",
+      `[paperclip] Claude session "${runtimeSessionId}" was saved for cwd "${runtimeSessionCwd}" and will not be resumed in "${cwd}".\n`,
+    );
+  }
   const template = sessionId ? promptTemplate : bootstrapTemplate;
   const prompt = renderTemplate(template, {
     company: { id: agent.companyId },
@@ -230,6 +242,9 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
     const resolvedSessionId =
       parsedStream.sessionId ??
       (asString(parsed.session_id, opts.fallbackSessionId ?? "") || opts.fallbackSessionId);
+    const resolvedSessionParams = resolvedSessionId
+      ? ({ sessionId: resolvedSessionId, cwd } as Record<string, unknown>)
+      : null;
 
     return {
       exitCode: proc.exitCode,
@@ -241,6 +256,8 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
           : describeClaudeFailure(parsed) ?? `Claude exited with code ${proc.exitCode ?? -1}`,
       usage,
       sessionId: resolvedSessionId,
+      sessionParams: resolvedSessionParams,
+      sessionDisplayId: resolvedSessionId,
       provider: "anthropic",
       model: parsedStream.model || asString(parsed.model, model),
       costUsd: parsedStream.costUsd ?? asNumber(parsed.total_cost_usd, 0),
@@ -267,7 +284,7 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
       return toAdapterResult(retry, { fallbackSessionId: null, clearSessionOnMissingSession: true });
     }
 
-    return toAdapterResult(initial, { fallbackSessionId: runtime.sessionId });
+    return toAdapterResult(initial, { fallbackSessionId: runtimeSessionId || runtime.sessionId });
   } finally {
     fs.rm(skillsDir, { recursive: true, force: true }).catch(() => {});
   }
diff --git a/packages/adapters/claude-local/src/server/index.ts b/packages/adapters/claude-local/src/server/index.ts
index bf3566b5..870b25e0 100644
--- a/packages/adapters/claude-local/src/server/index.ts
+++ b/packages/adapters/claude-local/src/server/index.ts
@@ -1,2 +1,35 @@
 export { execute } from "./execute.js";
 export { parseClaudeStreamJson, describeClaudeFailure, isClaudeUnknownSessionError } from "./parse.js";
+import type { AdapterSessionCodec } from "@paperclip/adapter-utils";
+
+function readNonEmptyString(value: unknown): string | null {
+  return typeof value === "string" && value.trim().length > 0 ? value.trim() : null;
+}
+
+export const sessionCodec: AdapterSessionCodec = {
+  deserialize(raw: unknown) {
+    if (typeof raw !== "object" || raw === null || Array.isArray(raw)) return null;
+    const record = raw as Record<string, unknown>;
+    const sessionId = readNonEmptyString(record.sessionId) ?? readNonEmptyString(record.session_id);
+    if (!sessionId) return null;
+    const cwd =
+      readNonEmptyString(record.cwd) ??
+      readNonEmptyString(record.workdir) ??
+      readNonEmptyString(record.folder);
+    return cwd ? { sessionId, cwd } : { sessionId };
+  },
+  serialize(params: Record<string, unknown> | null) {
+    if (!params) return null;
+    const sessionId = readNonEmptyString(params.sessionId) ?? readNonEmptyString(params.session_id);
+    if (!sessionId) return null;
+    const cwd =
+      readNonEmptyString(params.cwd) ??
+      readNonEmptyString(params.workdir) ??
+      readNonEmptyString(params.folder);
+    return cwd ? { sessionId, cwd } : { sessionId };
+  },
+  getDisplayId(params: Record<string, unknown> | null) {
+    if (!params) return null;
+    return readNonEmptyString(params.sessionId) ?? readNonEmptyString(params.session_id);
+  },
+};
diff --git a/packages/adapters/codex-local/src/server/execute.ts b/packages/adapters/codex-local/src/server/execute.ts
index b7b705d0..3fb942af 100644
--- a/packages/adapters/codex-local/src/server/execute.ts
+++ b/packages/adapters/codex-local/src/server/execute.ts
@@ -1,3 +1,4 @@
+import path from "node:path";
 import type { AdapterExecutionContext, AdapterExecutionResult } from "@paperclip/adapter-utils";
 import {
   asString,
@@ -13,7 +14,7 @@ import {
   renderTemplate,
   runChildProcess,
 } from "@paperclip/adapter-utils/server-utils";
-import { parseCodexJsonl } from "./parse.js";
+import { parseCodexJsonl, isCodexUnknownSessionError } from "./parse.js";
 
 export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExecutionResult> {
   const { runId, agent, runtime, config, context, onLog, onMeta, authToken } = ctx;
@@ -86,7 +87,19 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
     return asStringArray(config.args);
   })();
 
-  const sessionId = runtime.sessionId;
+  const runtimeSessionParams = parseObject(runtime.sessionParams);
+  const runtimeSessionId = asString(runtimeSessionParams.sessionId, runtime.sessionId ?? "");
+  const runtimeSessionCwd = asString(runtimeSessionParams.cwd, "");
+  const canResumeSession =
+    runtimeSessionId.length > 0 &&
+    (runtimeSessionCwd.length === 0 || path.resolve(runtimeSessionCwd) === path.resolve(cwd));
+  const sessionId = canResumeSession ? runtimeSessionId : null;
+  if (runtimeSessionId && !canResumeSession) {
+    await onLog(
+      "stderr",
+      `[paperclip] Codex session "${runtimeSessionId}" was saved for cwd "${runtimeSessionCwd}" and will not be resumed in "${cwd}".\n`,
+    );
+  }
   const template = sessionId ? promptTemplate : bootstrapTemplate;
   const prompt = renderTemplate(template, {
     company: { id: agent.companyId },
@@ -95,63 +108,104 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
     context,
   });
 
-  const args = ["exec", "--json"];
-  if (search) args.unshift("--search");
-  if (bypass) args.push("--dangerously-bypass-approvals-and-sandbox");
-  if (model) args.push("--model", model);
-  if (extraArgs.length > 0) args.push(...extraArgs);
-  if (sessionId) args.push("resume", sessionId, prompt);
-  else args.push(prompt);
-
-  if (onMeta) {
-    await onMeta({
-      adapterType: "codex_local",
-      command,
-      cwd,
-      commandArgs: args.map((value, idx) => {
-        if (!sessionId && idx === args.length - 1) return `<prompt ${prompt.length} chars>`;
-        if (sessionId && idx === args.length - 1) return `<prompt ${prompt.length} chars>`;
-        return value;
-      }),
-      env: redactEnvForLogs(env),
-      prompt,
-      context,
-    });
-  }
-
-  const proc = await runChildProcess(runId, command, args, {
-    cwd,
-    env,
-    timeoutSec,
-    graceSec,
-    onLog,
-  });
-
-  if (proc.timedOut) {
-    return {
-      exitCode: proc.exitCode,
-      signal: proc.signal,
-      timedOut: true,
-      errorMessage: `Timed out after ${timeoutSec}s`,
-    };
-  }
-
-  const parsed = parseCodexJsonl(proc.stdout);
-
-  return {
-    exitCode: proc.exitCode,
-    signal: proc.signal,
-    timedOut: false,
-    errorMessage: (proc.exitCode ?? 0) === 0 ? null : `Codex exited with code ${proc.exitCode ?? -1}`,
-    usage: parsed.usage,
-    sessionId: parsed.sessionId ?? runtime.sessionId,
-    provider: "openai",
-    model,
-    costUsd: null,
-    resultJson: {
-      stdout: proc.stdout,
-      stderr: proc.stderr,
-    },
-    summary: parsed.summary,
+  const buildArgs = (resumeSessionId: string | null) => {
+    const args = ["exec", "--json"];
+    if (search) args.unshift("--search");
+    if (bypass) args.push("--dangerously-bypass-approvals-and-sandbox");
+    if (model) args.push("--model", model);
+    if (extraArgs.length > 0) args.push(...extraArgs);
+    if (resumeSessionId) args.push("resume", resumeSessionId, prompt);
+    else args.push(prompt);
+    return args;
   };
+
+  const runAttempt = async (resumeSessionId: string | null) => {
+    const args = buildArgs(resumeSessionId);
+    if (onMeta) {
+      await onMeta({
+        adapterType: "codex_local",
+        command,
+        cwd,
+        commandArgs: args.map((value, idx) => {
+          if (idx === args.length - 1) return `<prompt ${prompt.length} chars>`;
+          return value;
+        }),
+        env: redactEnvForLogs(env),
+        prompt,
+        context,
+      });
+    }
+
+    const proc = await runChildProcess(runId, command, args, {
+      cwd,
+      env,
+      timeoutSec,
+      graceSec,
+      onLog,
+    });
+    return {
+      proc,
+      parsed: parseCodexJsonl(proc.stdout),
+    };
+  };
+
+  const toResult = (
+    attempt: { proc: { exitCode: number | null; signal: string | null; timedOut: boolean; stdout: string; stderr: string }; parsed: ReturnType<typeof parseCodexJsonl> },
+    clearSessionOnMissingSession = false,
+  ): AdapterExecutionResult => {
+    if (attempt.proc.timedOut) {
+      return {
+        exitCode: attempt.proc.exitCode,
+        signal: attempt.proc.signal,
+        timedOut: true,
+        errorMessage: `Timed out after ${timeoutSec}s`,
+        clearSession: clearSessionOnMissingSession,
+      };
+    }
+
+    const resolvedSessionId = attempt.parsed.sessionId ?? runtimeSessionId ?? runtime.sessionId ?? null;
+    const resolvedSessionParams = resolvedSessionId
+      ? ({ sessionId: resolvedSessionId, cwd } as Record<string, unknown>)
+      : null;
+
+    return {
+      exitCode: attempt.proc.exitCode,
+      signal: attempt.proc.signal,
+      timedOut: false,
+      errorMessage:
+        (attempt.proc.exitCode ?? 0) === 0
+          ? null
+          : `Codex exited with code ${attempt.proc.exitCode ?? -1}`,
+      usage: attempt.parsed.usage,
+      sessionId: resolvedSessionId,
+      sessionParams: resolvedSessionParams,
+      sessionDisplayId: resolvedSessionId,
+      provider: "openai",
+      model,
+      costUsd: null,
+      resultJson: {
+        stdout: attempt.proc.stdout,
+        stderr: attempt.proc.stderr,
+      },
+      summary: attempt.parsed.summary,
+      clearSession: Boolean(clearSessionOnMissingSession && !resolvedSessionId),
+    };
+  };
+
+  const initial = await runAttempt(sessionId);
+  if (
+    sessionId &&
+    !initial.proc.timedOut &&
+    (initial.proc.exitCode ?? 0) !== 0 &&
+    isCodexUnknownSessionError(initial.proc.stdout, initial.proc.stderr)
+  ) {
+    await onLog(
+      "stderr",
+      `[paperclip] Codex resume session "${sessionId}" is unavailable; retrying with a fresh session.\n`,
+    );
+    const retry = await runAttempt(null);
+    return toResult(retry, true);
+  }
+
+  return toResult(initial);
 }
diff --git a/packages/adapters/codex-local/src/server/index.ts b/packages/adapters/codex-local/src/server/index.ts
index 32b56e7c..d5fe5d1c 100644
--- a/packages/adapters/codex-local/src/server/index.ts
+++ b/packages/adapters/codex-local/src/server/index.ts
@@ -1,2 +1,35 @@
 export { execute } from "./execute.js";
-export { parseCodexJsonl } from "./parse.js";
+export { parseCodexJsonl, isCodexUnknownSessionError } from "./parse.js";
+import type { AdapterSessionCodec } from "@paperclip/adapter-utils";
+
+function readNonEmptyString(value: unknown): string | null {
+  return typeof value === "string" && value.trim().length > 0 ? value.trim() : null;
+}
+
+export const sessionCodec: AdapterSessionCodec = {
+  deserialize(raw: unknown) {
+    if (typeof raw !== "object" || raw === null || Array.isArray(raw)) return null;
+    const record = raw as Record<string, unknown>;
+    const sessionId = readNonEmptyString(record.sessionId) ?? readNonEmptyString(record.session_id);
+    if (!sessionId) return null;
+    const cwd =
+      readNonEmptyString(record.cwd) ??
+      readNonEmptyString(record.workdir) ??
+      readNonEmptyString(record.folder);
+    return cwd ? { sessionId, cwd } : { sessionId };
+  },
+  serialize(params: Record<string, unknown> | null) {
+    if (!params) return null;
+    const sessionId = readNonEmptyString(params.sessionId) ?? readNonEmptyString(params.session_id);
+    if (!sessionId) return null;
+    const cwd =
+      readNonEmptyString(params.cwd) ??
+      readNonEmptyString(params.workdir) ??
+      readNonEmptyString(params.folder);
+    return cwd ? { sessionId, cwd } : { sessionId };
+  },
+  getDisplayId(params: Record<string, unknown> | null) {
+    if (!params) return null;
+    return readNonEmptyString(params.sessionId) ?? readNonEmptyString(params.session_id);
+  },
+};
diff --git a/packages/adapters/codex-local/src/server/parse.ts b/packages/adapters/codex-local/src/server/parse.ts
index 0d2b6dbb..a14950f1 100644
--- a/packages/adapters/codex-local/src/server/parse.ts
+++ b/packages/adapters/codex-local/src/server/parse.ts
@@ -45,3 +45,14 @@ export function parseCodexJsonl(stdout: string) {
     usage,
   };
 }
+
+export function isCodexUnknownSessionError(stdout: string, stderr: string): boolean {
+  const haystack = `${stdout}\n${stderr}`
+    .split(/\r?\n/)
+    .map((line) => line.trim())
+    .filter(Boolean)
+    .join("\n");
+  return /unknown (session|thread)|session .* not found|thread .* not found|conversation .* not found/i.test(
+    haystack,
+  );
+}
diff --git a/server/src/__tests__/adapter-session-codecs.test.ts b/server/src/__tests__/adapter-session-codecs.test.ts
new file mode 100644
index 00000000..33cffc14
--- /dev/null
+++ b/server/src/__tests__/adapter-session-codecs.test.ts
@@ -0,0 +1,64 @@
+import { describe, expect, it } from "vitest";
+import { sessionCodec as claudeSessionCodec } from "@paperclip/adapter-claude-local/server";
+import { sessionCodec as codexSessionCodec, isCodexUnknownSessionError } from "@paperclip/adapter-codex-local/server";
+
+describe("adapter session codecs", () => {
+  it("normalizes claude session params with cwd", () => {
+    const parsed = claudeSessionCodec.deserialize({
+      session_id: "claude-session-1",
+      folder: "/tmp/workspace",
+    });
+    expect(parsed).toEqual({
+      sessionId: "claude-session-1",
+      cwd: "/tmp/workspace",
+    });
+
+    const serialized = claudeSessionCodec.serialize(parsed);
+    expect(serialized).toEqual({
+      sessionId: "claude-session-1",
+      cwd: "/tmp/workspace",
+    });
+    expect(claudeSessionCodec.getDisplayId?.(serialized ?? null)).toBe("claude-session-1");
+  });
+
+  it("normalizes codex session params with cwd", () => {
+    const parsed = codexSessionCodec.deserialize({
+      sessionId: "codex-session-1",
+      cwd: "/tmp/codex",
+    });
+    expect(parsed).toEqual({
+      sessionId: "codex-session-1",
+      cwd: "/tmp/codex",
+    });
+
+    const serialized = codexSessionCodec.serialize(parsed);
+    expect(serialized).toEqual({
+      sessionId: "codex-session-1",
+      cwd: "/tmp/codex",
+    });
+    expect(codexSessionCodec.getDisplayId?.(serialized ?? null)).toBe("codex-session-1");
+  });
+});
+
+describe("codex resume recovery detection", () => {
+  it("detects unknown session errors from codex output", () => {
+    expect(
+      isCodexUnknownSessionError(
+        '{"type":"error","message":"Unknown session id abc"}',
+        "",
+      ),
+    ).toBe(true);
+    expect(
+      isCodexUnknownSessionError(
+        "",
+        "thread 123 not found",
+      ),
+    ).toBe(true);
+    expect(
+      isCodexUnknownSessionError(
+        '{"type":"result","ok":true}',
+        "",
+      ),
+    ).toBe(false);
+  });
+});
diff --git a/server/src/adapters/index.ts b/server/src/adapters/index.ts
index 11637410..d02700d1 100644
--- a/server/src/adapters/index.ts
+++ b/server/src/adapters/index.ts
@@ -4,6 +4,7 @@ export type {
   AdapterExecutionContext,
   AdapterExecutionResult,
   AdapterInvocationMeta,
+  AdapterSessionCodec,
   UsageSummary,
   AdapterAgent,
   AdapterRuntime,
diff --git a/server/src/adapters/registry.ts b/server/src/adapters/registry.ts
index 452bc572..de3b3880 100644
--- a/server/src/adapters/registry.ts
+++ b/server/src/adapters/registry.ts
@@ -1,7 +1,7 @@
 import type { ServerAdapterModule } from "./types.js";
-import { execute as claudeExecute } from "@paperclip/adapter-claude-local/server";
+import { execute as claudeExecute, sessionCodec as claudeSessionCodec } from "@paperclip/adapter-claude-local/server";
 import { agentConfigurationDoc as claudeAgentConfigurationDoc, models as claudeModels } from "@paperclip/adapter-claude-local";
-import { execute as codexExecute } from "@paperclip/adapter-codex-local/server";
+import { execute as codexExecute, sessionCodec as codexSessionCodec } from "@paperclip/adapter-codex-local/server";
 import { agentConfigurationDoc as codexAgentConfigurationDoc, models as codexModels } from "@paperclip/adapter-codex-local";
 import { processAdapter } from "./process/index.js";
 import { httpAdapter } from "./http/index.js";
@@ -9,6 +9,7 @@ import { httpAdapter } from "./http/index.js";
 const claudeLocalAdapter: ServerAdapterModule = {
   type: "claude_local",
   execute: claudeExecute,
+  sessionCodec: claudeSessionCodec,
   models: claudeModels,
   supportsLocalAgentJwt: true,
   agentConfigurationDoc: claudeAgentConfigurationDoc,
@@ -17,6 +18,7 @@ const claudeLocalAdapter: ServerAdapterModule = {
 const codexLocalAdapter: ServerAdapterModule = {
   type: "codex_local",
   execute: codexExecute,
+  sessionCodec: codexSessionCodec,
   models: codexModels,
   supportsLocalAgentJwt: true,
   agentConfigurationDoc: codexAgentConfigurationDoc,
diff --git a/server/src/adapters/types.ts b/server/src/adapters/types.ts
index 3cd72846..76bd13bd 100644
--- a/server/src/adapters/types.ts
+++ b/server/src/adapters/types.ts
@@ -8,5 +8,6 @@ export type {
   AdapterExecutionResult,
   AdapterInvocationMeta,
   AdapterExecutionContext,
+  AdapterSessionCodec,
   ServerAdapterModule,
 } from "@paperclip/adapter-utils";