Codex History Viewer

Browse, search, organize, and resume past Codex CLI / Claude Code sessions through the official VS Code extensions or prepared CLI commands.

Latest release: 2.9.1 (2026-07-29).

Why Use This Extension?

Codex and Claude Code sessions can become hard to revisit once they are no longer active in the editor. Codex History Viewer keeps those local session files useful by presenting them in a searchable session history browser inside VS Code.

Use it to find past prompts, reuse useful answers, inspect file changes, organize sessions with tags and notes, resume same-source sessions, and prepare handoff context for other AI tools.

Highlights

• Revisit past Codex CLI and Claude Code sessions that are no longer easy to access from the active editor flow.
• Browse sessions in a year / month / day tree, a sortable session list, or project views with related project groups.
• Open History Insights for the current History target to review overview metrics, activity patterns, source/model/project/tool breakdowns, the most active sessions, frequently changed files, detailed usage/message/turn/file-type composition, and data quality.
• Optionally include Codex archived_sessions when the Codex source is enabled, and switch archive visibility instantly.
• Show valid cached History and Pinned data immediately at startup while local session files refresh in the background.
• Search across prompts, responses, tool output, tags, notes, and attachment metadata, with shared search history.
• View sessions in the Session Viewer with Markdown, code highlighting, math rendering, tool cards, and file-change diffs.
• Enable an opt-in Codex turn timeline to see turn boundaries, turn summaries, completed-turn folding, and running state in live mode.
• Use Agent Runs to distinguish Codex sub-agent sessions and inspect parent, sibling, and descendant relationships in a right-side tree. (Experimental; disabled by default.)
• Use Branch Navigation to inspect and switch between locally forked Codex histories and Claude Code Fork conversation histories in their respective session views. (Experimental; disabled by default.)
• Show Codex / Claude Code request interruptions as dedicated timeline cards.
• Open File AI Change History for a workspace file to review Codex / Claude Code diffs that touched that file.
• Bookmark important history cards and use date-guide markers to revisit them quickly.
• Keep open session tabs up to date with header-controlled auto-refresh modes.
• Show supported image attachments, Claude Code documents, and file references from Codex / Claude Code sessions as compact cards.
• Organize sessions with pins, tags, notes, custom titles, project aliases, project associations, saved searches, search history, display modes, and filters.
• Keep Pinned filters independent from History/Search, including project scope, source, archive visibility, tags, and saved sort preferences.
• Experimental opt-in restoration for session tabs, File AI Change History, and History Insights after Reload Window or VS Code restart.
• Resume past sessions through the official Codex and Claude Code VS Code extensions or prepare commands for resuming them with the CLI.
• Copy session IDs and session file paths from the Session Viewer or tree context menus, and reveal session files in their containing folders.
• Create handoff files and prompts when moving work to another AI tool.

Quick Start

1. Open the Activity Bar and select Codex History.
2. Use Control for global actions such as settings, import, rebuild cache, empty trash, and search defaults.
3. Browse sessions under History and switch between date-grouped/session-list layouts, List/Project display, All/Current Project Group scope, and saved sort preferences.
4. Use Show History Insights from the History header when you want an aggregate view of the current History target.
5. Select a session to open the reusable session tab. Use Open Session in Dedicated Tab to keep a session assigned to its own tab, or Open Session as Markdown for a virtual transcript document named after the session, such as Review release candidate.md. The virtual document does not create a file unless you explicitly save it.
6. Use Pinned for saved sessions with its own date, project, source, archive, tag, and saved sort controls.
7. Run Search... and refine with roles, query syntax, search history, saved searches, and the current History filters.
8. Use context menus or the Session Viewer's header actions to edit tags/notes and run bulk tag operations when needed.
9. Enable File Change History > Explorer Context Menu: Enabled when you want file-level AI diff history from file right-click menus.
10. Keep Codex enabled in Sources: Enabled, then turn on Codex archived sessions if you want archived Codex history included.
11. Enable codexHistoryViewer.agentRuns.enabled when you want to inspect parent and sub-agent relationships with Agent Runs.
12. Enable codexHistoryViewer.branchNavigation.enabled when you want to navigate locally forked Codex histories and Claude Code Fork conversation histories.
13. Choose Extension, CLI, or Extension and CLI as the resume method for each source. CLI actions enter a command in a new VS Code integrated terminal without running it; press Enter to execute it. Use Handoff to Other AI when moving work between agents.
14. Use the session information actions in the Session Viewer or Session Information in the History, Pinned, and Search context menus to copy a session ID or session file path, or reveal the session file in its containing folder.

History and Pinned Organization

History and Pinned separate project organization into display and scope controls. Display can switch between List and Project views, while scope can switch between All and Current Project Group. Project matching is case-insensitive across platforms. Project views preserve the existing layout choice: session-list history becomes Project -> Session, while date-grouped history becomes Project -> Year -> Month -> Day -> Session.

Project folders can have extension-local aliases from the History or Pinned project context menu. Aliases are stored in VS Code extension state without changing Codex or Claude Code history files. When set, aliases appear in project headings, session descriptions, tooltips, filter summaries, Status, and Search scope/session display while the original path remains available in detailed metadata.

Project associations can link another project's history into the current project display or group related projects together without moving the original history files. Associations are available from project context menus and are reflected in History, Pinned, Search, File AI Change History, and handoff content.

Pinned has its own project scope, source, archive visibility, date, tag filters, and saved sort preference. It does not follow History/Search filter state, so saved sessions can stay focused on a different project or source while you browse and search elsewhere. History can sort by started date, last activity date, or name. Pinned can sort by pinned time, started date, last activity date, or name.

Session Viewer

The Session Viewer renders local session files as readable timelines. It supports Markdown, syntax-highlighted fenced code blocks, KaTeX-compatible math, assistant usage metadata, environment snapshots, tool execution metadata, and grouped file-change cards from patch activity.

The resume button follows the resume method selected separately for Codex and Claude Code. Extension and CLI uses a split button: the last used method becomes the main action, while the dropdown always lists both methods. CLI actions enter the resume command in a new VS Code integrated terminal without pressing Enter. The History, Pinned, and Search context menus follow the same source-specific settings.

The Session Viewer shows the validated session ID and session file name with actions to copy the ID, copy the full file path, or reveal the file in its containing folder. The same actions are available under Session Information in the History, Pinned, and Search context menus.

Tree context menus distinguish single-session actions from bulk actions. Resume, CLI preparation, handoff, session information, and custom-title actions always use the explicitly right-clicked session. Open, Markdown, annotation, export, pin/unpin, promote, and delete actions use the same-view multi-selection only when it includes the right-clicked row; otherwise they use that row alone. Codex and Claude Code sessions can be mixed for these bulk actions. Archive and restore remain Codex-only and reject the whole selection when its source or archive state is incompatible. Menu availability is determined by the right-clicked row, and selections from different views are never combined.

Large histories can use the auto, normal, or simplified performance mode. Heavy tool details and large diff rows can be deferred until Show details is enabled or an individual entry is expanded.

Codex sessions can use an opt-in turn timeline. basic mode shows turn start/end markers, range rails, summaries, token counts, duration, and manual folding for completed turns. live mode adds running-turn indicators, elapsed time, and update activity effects.

Patch group cards can show compact file summaries and an in-place Open all diffs / Close all diffs action.

Request interruptions from Codex and Claude Code render as dedicated timeline cards. When available, details include reason, duration, turn ID, rollback state, and rolled-back turn count.

Session tabs preserve useful state across reload and auto-refresh, including scroll position, selected message, expanded cards/diffs, detail visibility, diff wrapping, and in-page search state. The experimental opt-in Restore Webview Tabs After Reload setting can also restore session, File AI Change History, and History Insights panels after Developer: Reload Window or VS Code restart. It is disabled by default because VS Code can defer Webview restoration and may occasionally create duplicate tabs when the same history is opened again.

The session timeline can keep the current user prompt visible at the top while you scroll. Codex memory citation information is rendered as a collapsible section instead of being left as raw metadata in the message body. Session runtime context and local-command output are likewise shown as collapsed cards instead of raw user messages.

Attachments and References

The Session Viewer keeps attachments and file references out of the message body and renders them as cards instead.

• Supported images from Codex / Claude Code sessions are loaded on demand and can be previewed or saved.
• Claude Code PDF, text, and generic documents render as document cards. Text document previews open inside the card, and embedded payloads are saved on demand.
• Claude Code IDE opened-file and selection markers render as file/selection reference cards instead of raw inline tags.
• Codex mentioned-file blocks render as file reference cards while the actual request body remains as message text, including blocks that appear after IDE context.
• File reference cards can open local files through VS Code. Referenced files are not read automatically for rendering, search, resume, or handoff.
• Card metadata such as path, MIME type, and size is available from tooltips instead of taking over the session timeline.
• Markdown transcripts, resume text, and handoff files use clean text plus attachment summaries instead of repeating raw tags or file blocks.

Search

Search is local, cancellable, and backed by an incremental search index. It can search message text, configured tool metadata, titles, tags, notes, and attachment metadata.

Supported query forms include normal substring search, exact:..., re:..., /regex/, and boolean AND / OR / NOT.

Search follows the current History target, including date, project scope, project filter, source, archive visibility, and tags. It does not follow Pinned filters, and it does not create Search results from filters alone.

The global search input combines manual search and search history. Search history is shared with in-page search in the Session Viewer and File AI Change History, stores only query text, and can be selected to run or removed individually with the trash button. Saved searches also store and reuse only query text; role filters and case sensitivity are taken from the current settings when the saved search is run, and saved searches can be removed individually from the run picker.

Opening a Search result can pass the same query into the Session Viewer's in-page search. In-page search in the Session Viewer and File AI Change History supports the same query forms, including exact matching and regular expressions, and can show search-history suggestions below the search input.

Project aliases are shown in Search scope and result display, but they are not added to the search index or treated as searchable hit text.

The search index can be tuned with codexHistoryViewer.search.indexToolContent:

• conversationOnly
• toolCalls
• toolCallsAndOutputs

Attachment indexing includes labels, paths, MIME types, file kinds, and bounded text from Claude Code text documents. PDF / Office / binary / base64 document contents and Codex referenced-file contents are not indexed.

Codex Archived Sessions

Codex History Viewer can optionally read Codex archived_sessions in addition to normal Codex sessions. Archived sessions can be shown as active only, archived only, or all. Search follows the History archive-visibility scope, while Pinned keeps its own independent archive-visibility state. Active Codex sessions expose Move to Archive, while archived Codex sessions expose Move to Codex History.

Archive and restore operations prefer the official Codex provider. Moving archived sessions back to normal Codex history can fall back to a filesystem move when the official provider is unavailable. Pins, annotations, bookmarks, and saved session positions are relocated when the session path changes.

Handoff to Other AI

Handoff actions appear under Handoff to Other AI for visible Codex / Claude Code sessions when codexHistoryViewer.handoff.enabled is enabled. They can create a reusable handoff file, copy a prompt that points another AI to that file, or open the handoff file for manual use. Codex sessions can also be handed off directly to Claude Code when the Claude Code extension is available.

Handoff files are stored in this extension's VS Code global storage and include a tail-prioritized transcript excerpt, the latest user request, the source session path, recoverable file changes, and attachment summaries. Tool calls, tool outputs, and binary attachment payloads are intentionally omitted.

When project associations are configured, handoff generation follows the associated project display and includes path mapping context for the receiving AI.

File AI Change History

File AI Change History starts from a workspace file and shows the Codex / Claude Code changes that touched that file over time.

Use it when you want to answer questions such as:

• Which AI session changed this file?
• How did this file evolve across Codex and Claude Code sessions?
• What was the surrounding session context for a specific diff?

The Explorer file context menu entry is opt-in. Enable File Change History > Explorer Context Menu: Enabled, then right-click a file in VS Code Explorer and run Show File AI Change History.

The view is scoped to the current workspace and selected file. It supports Codex / Claude Code source toggles, in-page search with shared query history and richer query syntax, incremental Load more, previous/next navigation, and Open in History links back to the matching diff card in the original session.

File AI Change History follows project associations when resolving related history, so associated project displays and path mappings are reflected when possible.

History Insights

History Insights turns the current History target into a fixed analytics snapshot. Open it from Show History Insights in the History view header or from the Command Palette.

The view includes overview metrics, an activity heatmap, breakdowns by source, model, project, and tool, the most active sessions, frequently changed files, usage details, and data quality information. The overview includes reasoning tokens and change events, and the heatmap can visualize reasoning tokens. Tool breakdowns can switch between call count and session count. Most-active-session rankings can switch between user requests, tool calls, reasoning tokens, total tokens, and changed lines, and each available row can open its session. Usage details summarize cached, cache-read, and cache-creation input tokens and reasoning tokens; user requests, assistant responses, developer messages, tool calls, and tool outputs; all, completed, interrupted, and rolled-back turns; and changed file types by distinct-file and change-event count. Partial logs are shown as confirmed lower bounds or unavailable values instead of being treated as exact zeros.

Reaggregate updates changed sessions while keeping the same target set. Apply History filters replaces the snapshot with the current History target. The filter panel can refine source, date range, Codex storage location, related project groups, and tags. These changes stay inside History Insights by default; they update the History view only when Also apply to History is selected before applying them.

Selecting a date cell opens its sessions in History. The History and Search actions on each project row apply that project while preserving the other snapshot conditions. The Search action reruns the current search when one is available, then opens the Search view. Frequently changed file entries can open the existing File AI Change History view or the corresponding workspace file.

Agent Runs (Experimental)

Agent Runs currently supports Codex sessions only. When it is enabled and its relationship data is ready, sub-agent sessions with an available parent are omitted from History. They remain reachable from the parent session's Agent Runs panel, Search, and explicit Pinned entries. Sub-agent sessions whose parent cannot be resolved safely remain visible in History.

The Agent Runs action in a Codex session view opens a right-side relationship tree containing the parent, siblings, and descendants of the current session. The current route is blue, other agent routes are orange, and the open icon on each available node opens that related session directly.

Enable codexHistoryViewer.agentRuns.enabled to use this feature. Relationships are based only on explicit agent metadata; the feature does not merge session content, usage totals, annotations, or stored session files. (Experimental; disabled by default.)

Branch Navigation (Experimental)

Branch Navigation recognizes locally forked Codex session histories, including histories created with Fork locally in the Codex app or Continue in new task in the Codex extension, and Claude Code histories created with Fork conversation. It lets you move between Fork destinations without leaving their respective session views.

Inline controls at a Fork point switch to the previous or next route. The shared route-tree action shows the shared history, Fork points, and the start and end of each route. Selecting a route node switches the same session view to the corresponding stored session and message position.

Enable codexHistoryViewer.branchNavigation.enabled to use this feature. For Codex, Branch Navigation applies to local Forks whose parent and child remain in the same working directory. For Claude Code, Branch Navigation only navigates stored session history and does not invoke Rewind code or rewind workspace files. The extension never creates, modifies, merges, or deletes Forks or modifies stored session files. (Experimental; disabled by default.)

Configuration

Most settings are available from VS Code Settings under Codex History Viewer. Common settings include:

• codexHistoryViewer.sources.enabled: enable codex (Codex), claude (Claude Code), or both. VS Code Settings and settings.json use the stored identifiers codex and claude.
• codexHistoryViewer.sessionsRoot: Codex sessions root.
• codexHistoryViewer.claude.sessionsRoot: Claude Code sessions root.
• codexHistoryViewer.agentRuns.enabled: enable the experimental Agent Runs feature. It currently supports Codex sessions only. Disabled by default.
• codexHistoryViewer.branchNavigation.enabled: enable the experimental Branch Navigation feature for locally forked Codex histories and Claude Code Fork conversation histories. Disabled by default.
• codexHistoryViewer.codex.archivedSessions.enabled: include Codex archived sessions.
• codexHistoryViewer.handoff.enabled: show cross-agent handoff actions.
• codexHistoryViewer.resume.codexMethod: choose Extension, CLI, or Extension and CLI for resuming Codex sessions.
• codexHistoryViewer.resume.claudeMethod: choose Extension, CLI, or Extension and CLI for resuming Claude Code sessions.
• codexHistoryViewer.preview.tooltipMode: choose Detailed, Compact, or Title Only for session tree item tooltips.
• codexHistoryViewer.preview.maxMessages: set the maximum number of user/assistant messages collected for Detailed tooltips. This is not a guaranteed visible count; VS Code limits tooltip height to approximately 50% of the window, so some collected messages may be outside the visible area.
• codexHistoryViewer.search.indexToolContent: control search index tool-content scope.
• codexHistoryViewer.fileChangeHistory.explorerContextMenu.enabled: show File AI Change History in Explorer.
• codexHistoryViewer.autoRefresh.enabled: watch local session files and refresh the History tree and opted-in session tabs when the VS Code window is focused and the History tree is visible or an opted-in session tab is open.
• codexHistoryViewer.chat.openPosition: open the session view at the top, the last viewed message, or the latest rendered card.
• codexHistoryViewer.chat.stickyUserPrompt: keep the current user prompt visible while scrolling the session timeline.
• codexHistoryViewer.chat.performanceMode: choose the default session rendering performance mode.
• codexHistoryViewer.chat.turnTimeline.mode: enable the opt-in Codex turn timeline with off, basic, or live.
• codexHistoryViewer.webview.restoreAfterReload: experimental opt-in to restoring session tabs, File AI Change History, and History Insights after Reload Window or VS Code restart.
• codexHistoryViewer.images.enabled: show supported image attachments.
• codexHistoryViewer.ui.timeGuide.enabled: enable compact date guides and bookmark controls.
• codexHistoryViewer.ui.language: choose auto, en, or ja.

Suggested Settings

The defaults are designed for regular use. These settings are useful starting points when you want a lighter UI, richer search, or more active refresh behavior:

If history, search, or analysis results look stale, run Control > Rebuild Cache. After confirmation, it recreates the history cache, search index, and analysis data. A successful Rebuild Cache refreshes open History Insights and Branch Navigation only when its starting configuration is still current.

Commands

Most actions are available from view title buttons and tree context menus.

For the primary user-facing commands with descriptions, see:

• Command Reference

Codex Integration Notes

• The first Resume in Codex may show a VS Code security prompt for the target extension URI. Click Open to continue.
• If the official Codex extension stops reopening a session, try Developer: Reload Webviews, then Developer: Restart Extension Host, then Developer: Reload Window.
• Move to Archive and Move to Codex History use the official Codex provider when available. Moving archived sessions back to normal history can fall back to a filesystem move if needed.

What's New in 2.9.1

• Fixed an issue where session tooltips could flicker when they appeared under the mouse pointer while Tooltip Mode was set to Detailed.
• Clarified the Preview: Max Messages setting description to explain that it controls the maximum number of messages collected for detailed tooltips, rather than the number of messages guaranteed to be displayed, and that VS Code limits tooltip height to approximately 50% of the window.

Changelog

See CHANGELOG.

Security

See SECURITY. Use the latest release whenever possible; do not install or redistribute v1.2.1 or earlier VSIX files.

Privacy

This extension reads local session files and renders them inside VS Code. It does not implement any network communication and does not send session content anywhere.

If you use Copy Quick Prompt or Copy Handoff Prompt to Clipboard, this extension copies session context to your clipboard. Data is only sent externally if you paste it into another tool or extension.

When you open a session as a Markdown transcript, the generated transcript includes local paths such as the session file path and CWD. Review before sharing.

Disclaimer

Codex History Viewer is an independent project and is not affiliated with, endorsed by, or officially associated with OpenAI, Anthropic, Codex, or Claude Code.

This extension works with locally stored session and history files created by official tools and extensions. Their file formats and internal behaviors may change without notice, which may affect compatibility.

Archive, restore, delete, import, and other file operations are designed to be conservative, but they may move or modify local files and extension-managed metadata. The author and contributors cannot guarantee recovery of lost or corrupted data.

Please keep backups of important session data.