diff --git a/packages/ai/src/index.ts b/packages/ai/src/index.ts
index 0fab4dbd..73a56538 100644
--- a/packages/ai/src/index.ts
+++ b/packages/ai/src/index.ts
@@ -3,6 +3,7 @@ export * from "./providers/anthropic.js";
 export * from "./providers/google.js";
 export * from "./providers/google-gemini-cli.js";
 export * from "./providers/google-vertex.js";
+export * from "./providers/openai-codex/index.js";
 export * from "./providers/openai-completions.js";
 export * from "./providers/openai-responses.js";
 export * from "./stream.js";
diff --git a/packages/ai/src/providers/openai-codex/index.ts b/packages/ai/src/providers/openai-codex/index.ts
new file mode 100644
index 00000000..86575ded
--- /dev/null
+++ b/packages/ai/src/providers/openai-codex/index.ts
@@ -0,0 +1,7 @@
+/**
+ * OpenAI Codex utilities - exported for use by coding-agent export
+ */
+
+export { type CacheMetadata, getCodexInstructions, getModelFamily, type ModelFamily } from "./prompts/codex.js";
+export { buildCodexPiBridge } from "./prompts/pi-codex-bridge.js";
+export { buildCodexSystemPrompt, type CodexSystemPrompt } from "./prompts/system-prompt.js";
diff --git a/packages/coding-agent/src/core/agent-session.ts b/packages/coding-agent/src/core/agent-session.ts
index 60868127..9deedc53 100644
--- a/packages/coding-agent/src/core/agent-session.ts
+++ b/packages/coding-agent/src/core/agent-session.ts
@@ -2057,9 +2057,9 @@ export class AgentSession {
 	 * @param outputPath Optional output path (defaults to session directory)
 	 * @returns Path to exported file
 	 */
-	exportToHtml(outputPath?: string): string {
+	async exportToHtml(outputPath?: string): Promise<string> {
 		const themeName = this.settingsManager.getTheme();
-		return exportSessionToHtml(this.sessionManager, this.state, { outputPath, themeName });
+		return await exportSessionToHtml(this.sessionManager, this.state, { outputPath, themeName });
 	}
 
 	// =========================================================================
diff --git a/packages/coding-agent/src/core/export-html/index.ts b/packages/coding-agent/src/core/export-html/index.ts
index 577f262c..a25d39b7 100644
--- a/packages/coding-agent/src/core/export-html/index.ts
+++ b/packages/coding-agent/src/core/export-html/index.ts
@@ -1,4 +1,5 @@
-import type { AgentState } from "@mariozechner/pi-agent-core";
+import type { AgentState, AgentTool } from "@mariozechner/pi-agent-core";
+import { buildCodexPiBridge, getCodexInstructions } from "@mariozechner/pi-ai";
 import { existsSync, readFileSync, writeFileSync } from "fs";
 import { basename, join } from "path";
 import { APP_NAME, getExportTemplateDir } from "../../config.js";
@@ -10,6 +11,37 @@ export interface ExportOptions {
 	themeName?: string;
 }
 
+/** Info about Codex injection to show inline with model_change entries */
+interface CodexInjectionInfo {
+	/** Codex instructions text */
+	instructions: string;
+	/** Bridge text (tool list) */
+	bridge: string;
+}
+
+/**
+ * Build Codex injection info for display inline with model_change entries.
+ */
+async function buildCodexInjectionInfo(tools?: AgentTool[]): Promise<CodexInjectionInfo | undefined> {
+	// Try to get cached instructions for default model family
+	let instructions: string | null = null;
+	try {
+		instructions = await getCodexInstructions("gpt-5.1-codex");
+	} catch {
+		// Cache miss - that's fine
+	}
+
+	const bridgeText = buildCodexPiBridge(tools);
+
+	const instructionsText =
+		instructions || "(Codex instructions not cached. Run a Codex request to populate the local cache.)";
+
+	return {
+		instructions: instructionsText,
+		bridge: bridgeText,
+	};
+}
+
 /** Parse a color string to RGB values. Supports hex (#RRGGBB) and rgb(r,g,b) formats. */
 function parseColor(color: string): { r: number; g: number; b: number } | undefined {
 	const hexMatch = color.match(/^#([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})$/);
@@ -103,6 +135,8 @@ interface SessionData {
 	entries: ReturnType<SessionManager["getEntries"]>;
 	leafId: string | null;
 	systemPrompt?: string;
+	/** Info for rendering Codex injection inline with model_change entries */
+	codexInjectionInfo?: CodexInjectionInfo;
 	tools?: { name: string; description: string }[];
 }
 
@@ -146,7 +180,11 @@ function generateHtml(sessionData: SessionData, themeName?: string): string {
  * Export session to HTML using SessionManager and AgentState.
  * Used by TUI's /export command.
  */
-export function exportSessionToHtml(sm: SessionManager, state?: AgentState, options?: ExportOptions | string): string {
+export async function exportSessionToHtml(
+	sm: SessionManager,
+	state?: AgentState,
+	options?: ExportOptions | string,
+): Promise<string> {
 	const opts: ExportOptions = typeof options === "string" ? { outputPath: options } : options || {};
 
 	const sessionFile = sm.getSessionFile();
@@ -162,6 +200,7 @@ export function exportSessionToHtml(sm: SessionManager, state?: AgentState, opti
 		entries: sm.getEntries(),
 		leafId: sm.getLeafId(),
 		systemPrompt: state?.systemPrompt,
+		codexInjectionInfo: await buildCodexInjectionInfo(state?.tools),
 		tools: state?.tools?.map((t) => ({ name: t.name, description: t.description })),
 	};
 
@@ -181,7 +220,7 @@ export function exportSessionToHtml(sm: SessionManager, state?: AgentState, opti
  * Export session file to HTML (standalone, without AgentState).
  * Used by CLI for exporting arbitrary session files.
  */
-export function exportFromFile(inputPath: string, options?: ExportOptions | string): string {
+export async function exportFromFile(inputPath: string, options?: ExportOptions | string): Promise<string> {
 	const opts: ExportOptions = typeof options === "string" ? { outputPath: options } : options || {};
 
 	if (!existsSync(inputPath)) {
@@ -195,6 +234,7 @@ export function exportFromFile(inputPath: string, options?: ExportOptions | stri
 		entries: sm.getEntries(),
 		leafId: sm.getLeafId(),
 		systemPrompt: undefined,
+		codexInjectionInfo: await buildCodexInjectionInfo(undefined),
 		tools: undefined,
 	};
 
diff --git a/packages/coding-agent/src/core/export-html/template.css b/packages/coding-agent/src/core/export-html/template.css
index 8fbdcd01..354ae74a 100644
--- a/packages/coding-agent/src/core/export-html/template.css
+++ b/packages/coding-agent/src/core/export-html/template.css
@@ -512,6 +512,39 @@
       font-weight: bold;
     }
 
+    .codex-bridge-toggle {
+      color: var(--muted);
+      cursor: pointer;
+      text-decoration: underline;
+      font-size: 10px;
+    }
+
+    .codex-bridge-toggle:hover {
+      color: var(--accent);
+    }
+
+    .codex-bridge-content {
+      display: none;
+      margin-top: 8px;
+      padding: 8px;
+      background: var(--exportCardBg);
+      border-radius: 4px;
+      font-size: 11px;
+      max-height: 300px;
+      overflow: auto;
+    }
+
+    .codex-bridge-content pre {
+      margin: 0;
+      white-space: pre-wrap;
+      word-break: break-word;
+      color: var(--muted);
+    }
+
+    .model-change.show-bridge .codex-bridge-content {
+      display: block;
+    }
+
     /* Compaction / Branch Summary - matches customMessage colors from TUI */
     .compaction {
       background: var(--customMessageBg);
@@ -593,6 +626,17 @@
       display: block;
     }
 
+    .system-prompt.provider-prompt {
+      border-left: 3px solid var(--warning);
+    }
+
+    .system-prompt-note {
+      font-size: 10px;
+      font-style: italic;
+      color: var(--muted);
+      margin-top: 4px;
+    }
+
     /* Tools list */
     .tools-list {
       background: var(--customMessageBg);
diff --git a/packages/coding-agent/src/core/export-html/template.js b/packages/coding-agent/src/core/export-html/template.js
index 6d3e5929..48311d87 100644
--- a/packages/coding-agent/src/core/export-html/template.js
+++ b/packages/coding-agent/src/core/export-html/template.js
@@ -12,7 +12,7 @@
         bytes[i] = binary.charCodeAt(i);
       }
       const data = JSON.parse(new TextDecoder('utf-8').decode(bytes));
-      const { header, entries, leafId: defaultLeafId, systemPrompt, tools } = data;
+      const { header, entries, leafId: defaultLeafId, systemPrompt, codexInjectionInfo, tools } = data;
 
       // ============================================================
       // URL PARAMETER HANDLING
@@ -954,7 +954,17 @@
         }
 
         if (entry.type === 'model_change') {
-          return `<div class="model-change" id="${entryId}">${tsHtml}Switched to model: <span class="model-name">${escapeHtml(entry.provider)}/${escapeHtml(entry.modelId)}</span></div>`;
+          let html = `<div class="model-change" id="${entryId}">${tsHtml}Switched to model: <span class="model-name">${escapeHtml(entry.provider)}/${escapeHtml(entry.modelId)}</span>`;
+          
+          // Show expandable bridge prompt info when switching to openai-codex
+          if (entry.provider === 'openai-codex' && codexInjectionInfo) {
+            const fullContent = `# Codex Instructions\n${codexInjectionInfo.instructions}\n\n# Codex-Pi Bridge\n${codexInjectionInfo.bridge}`;
+            html += ` <span class="codex-bridge-toggle" onclick="event.stopPropagation(); this.parentElement.classList.toggle('show-bridge')">[bridge prompt]</span>`;
+            html += `<div class="codex-bridge-content"><pre>${escapeHtml(fullContent)}</pre></div>`;
+          }
+          
+          html += '</div>';
+          return html;
         }
 
         if (entry.type === 'compaction') {
@@ -1060,6 +1070,7 @@
             </div>
           </div>`;
 
+        // Render system prompt (user's base prompt, applies to all providers)
         if (systemPrompt) {
           const lines = systemPrompt.split('\n');
           const previewLines = 10;
diff --git a/packages/coding-agent/src/main.ts b/packages/coding-agent/src/main.ts
index 92754958..da8d0e6c 100644
--- a/packages/coding-agent/src/main.ts
+++ b/packages/coding-agent/src/main.ts
@@ -368,7 +368,7 @@ export async function main(args: string[]) {
 	if (parsed.export) {
 		try {
 			const outputPath = parsed.messages.length > 0 ? parsed.messages[0] : undefined;
-			const result = exportFromFile(parsed.export, outputPath);
+			const result = await exportFromFile(parsed.export, outputPath);
 			console.log(`Exported to: ${result}`);
 			return;
 		} catch (error: unknown) {
diff --git a/packages/coding-agent/src/modes/interactive/interactive-mode.ts b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
index e5a1af3d..9f439cc0 100644
--- a/packages/coding-agent/src/modes/interactive/interactive-mode.ts
+++ b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
@@ -1051,7 +1051,7 @@ export class InteractiveMode {
 				return;
 			}
 			if (text.startsWith("/export")) {
-				this.handleExportCommand(text);
+				await this.handleExportCommand(text);
 				this.editor.setText("");
 				return;
 			}
@@ -2453,12 +2453,12 @@ export class InteractiveMode {
 	// Command handlers
 	// =========================================================================
 
-	private handleExportCommand(text: string): void {
+	private async handleExportCommand(text: string): Promise<void> {
 		const parts = text.split(/\s+/);
 		const outputPath = parts.length > 1 ? parts[1] : undefined;
 
 		try {
-			const filePath = this.session.exportToHtml(outputPath);
+			const filePath = await this.session.exportToHtml(outputPath);
 			this.showStatus(`Session exported to: ${filePath}`);
 		} catch (error: unknown) {
 			this.showError(`Failed to export session: ${error instanceof Error ? error.message : "Unknown error"}`);
@@ -2481,7 +2481,7 @@ export class InteractiveMode {
 		// Export to a temp file
 		const tmpFile = path.join(os.tmpdir(), "session.html");
 		try {
-			this.session.exportToHtml(tmpFile);
+			await this.session.exportToHtml(tmpFile);
 		} catch (error: unknown) {
 			this.showError(`Failed to export session: ${error instanceof Error ? error.message : "Unknown error"}`);
 			return;
diff --git a/packages/coding-agent/src/modes/rpc/rpc-mode.ts b/packages/coding-agent/src/modes/rpc/rpc-mode.ts
index 8a429d5d..3fd7690b 100644
--- a/packages/coding-agent/src/modes/rpc/rpc-mode.ts
+++ b/packages/coding-agent/src/modes/rpc/rpc-mode.ts
@@ -443,7 +443,7 @@ export async function runRpcMode(session: AgentSession): Promise<never> {
 			}
 
 			case "export_html": {
-				const path = session.exportToHtml(command.outputPath);
+				const path = await session.exportToHtml(command.outputPath);
 				return success(id, "export_html", { path });
 			}