feat: multi-tab terminals, batch polling, security hardening by datasciencemonkey · Pull Request #46 · datasciencemonkey/coding-agents-databricks-apps

datasciencemonkey · 2026-03-08T09:56:11Z

Summary

Multi-tab terminal support with full keyboard navigation (Ctrl+Shift+T/W/1-9)
CoDA ASCII art splash screen on terminal launch
Keyboard shortcuts help popup (Ctrl+/)
Batch polling — single /api/output-batch request for all panes instead of N individual requests
Security response headers — X-Content-Type-Options, X-Frame-Options, X-XSS-Protection, Referrer-Policy
SIGTERM handler fix — only registered in gunicorn (production), not at module level
Web Worker rewrite — batch polling with retry-on-shutdown for auto-recovery
Release workflow — manual GitHub Actions workflow to cut versioned releases

Tmux Evaluation

Evaluated tmux for session persistence — rejected due to visual artifacts (status bar, dot fill, resize conflicts) and limited value (doesn't survive container restarts). See docs/2026-03-08-tmux-evaluation.md for full analysis. Batch polling idea inspired by discussion with @dgokeeffe.

Test plan

Terminal loads with CoDA splash screen (no tmux artifacts)
Batch polling works (/api/output-batch returns all pane outputs)
shutting_down: false on fresh server start
Kill→restart cycle: shutting_down stays false
Security headers present in responses
Deploy to Databricks Apps and verify

🤖 Generated with Claude Code

Approved design for browser-style tabs where each tab owns its own split-pane layout, with renamable labels and a 5-tab cap. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

11-task plan covering tab bar UI, state model refactor, keyboard shortcuts, and pane-per-tab scoping. Frontend-only change. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

The subagent introduced \\!== instead of \!== in the SearchAddon and ImageAddon type checks, causing a syntax error that prevented init() from running. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Clicking the already-active tab triggered switchTab → renderTabBar, which destroyed and recreated the DOM elements before the dblclick event could fire. Now switchTab returns early if already on that tab. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…llowing Ctrl+Shift+number was being consumed by xterm.js before our handler. Using capture phase (3rd arg = true) ensures our shortcuts fire first. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

On macOS, Alt+Shift+D produces 'Î' not 'D' for e.key. Using e.code (physical key) makes shortcuts work regardless of OS key remapping. Also added stopPropagation to prevent xterm.js from processing them. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Added overflow:hidden + text-overflow:ellipsis on .tab-label and flex-shrink:0 on .tab-close so the X button never gets pushed out. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Replaces the plain welcome text with a cyan ASCII block-letter "CoDA" logo (with lowercase o), tagline, version indicator, and keyboard shortcut hints. Closes #43 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

…ext" This reverts commit 373d56f.

Adds a "?" button in the toolbar and Ctrl+/ keybinding to toggle a modal overlay showing all keyboard shortcuts grouped by category. Dismissible via Escape, click-outside, or the shortcut toggle. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Now that the shortcuts help popup exists, point users there instead of listing individual shortcuts in the splash screen. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

- version.json at project root (readable by backend, frontend, CI/CD) - Backend loads version at startup, exposes /api/version endpoint - Health endpoint now includes version - Frontend fetches version from /api/version for splash screen Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Standard Python project convention. Backend reads version via tomllib. Frontend still fetches from /api/version. CI can read with: python -c "import tomllib; print(tomllib.load(open('pyproject.toml','rb'))['project']['version'])" Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

- Manual workflow_dispatch to create tagged releases from pyproject.toml - Auto-generates categorized release notes from conventional commits - Guards against duplicate tags and invalid semver - Update project description to "CoDA - Coding Agents on Databricks Apps" Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

- Add /api/output-batch endpoint for multi-pane polling efficiency - Rewrite poll-worker.js to use batch polling (1 request per cycle) - Add security response headers (X-Content-Type-Options, etc.) - Fix SIGTERM handler: register only in gunicorn, not at module level - Fix top-level await bug in frontend init() - Worker retries on shutting_down instead of dying permanently - Document tmux evaluation and decision to not adopt See docs/2026-03-08-tmux-evaluation.md for full analysis. Co-Authored-By: dgokeeffe <david.okeeffe@databricks.com> Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

datasciencemonkey · 2026-03-08T12:02:29Z

will come back tmux at a later time - sync with David offline.

Add silent retry threshold (5 consecutive failures) before showing "Connection lost" banner. Transient blips on Databricks Apps proxy/LB are retried silently with 500ms delay instead of alarming the user. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Use percentage-based heights instead of viewport units (100vh/100vw) so the terminal fits within the Databricks Apps iframe container without overflowing at the bottom. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Add 2px bottom padding to pane container so xterm.js fit addon has breathing room and doesn't squeeze in a row that gets cut off by overflow: hidden. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Add cursorAccent color to all themes so block cursors have proper contrast. Brighten cursor color in Dark and Nord themes where it was identical to foreground and nearly invisible. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

datasciencemonkey and others added 26 commits March 8, 2026 04:39

docs: add multi-tab terminals design

dbbf5e7

Approved design for browser-style tabs where each tab owns its own split-pane layout, with renamable labels and a 5-tab cap. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs: add multi-tab terminals implementation plan

66d4079

11-task plan covering tab bar UI, state model refactor, keyboard shortcuts, and pane-per-tab scoping. Frontend-only change. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

feat: add tab bar HTML and CSS

cc01468

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

refactor: introduce tabs array data model

5745918

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

refactor: update theme/font/refit to use tabs model

7446427

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

refactor: createPane now accepts parent tab

192f283

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

feat: implement createTab, switchTab, closeTab, renameTab

68711a6

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

refactor: pane operations now scoped to active tab

6ca9542

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

refactor: divider drag scoped to parent tab

2656c78

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

feat: add tab keyboard shortcuts, move pane shortcuts to Alt+Shift

7003e8f

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

feat: wire new-tab button, update cleanup for tabs

79df0a9

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

feat: init creates first tab, multi-tab terminals complete

8aab33c

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: remove escaped backslashes in createPane JS

b97b214

The subagent introduced \\!== instead of \!== in the SearchAddon and ImageAddon type checks, causing a syntax error that prevented init() from running. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

feat: increase max tabs from 5 to 10, extend jump shortcut to 1-9

82dcbca

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: use capture phase for keyboard shortcuts to prevent xterm.js swa…

42bc7aa

…llowing Ctrl+Shift+number was being consumed by xterm.js before our handler. Using capture phase (3rd arg = true) ensures our shortcuts fire first. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: truncate long tab labels with ellipsis, keep close button visible

aba8af1

Added overflow:hidden + text-overflow:ellipsis on .tab-label and flex-shrink:0 on .tab-close so the X button never gets pushed out. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

feat: add CoDA ASCII art splash screen on terminal launch

1c2456f

Replaces the plain welcome text with a cyan ASCII block-letter "CoDA" logo (with lowercase o), tagline, version indicator, and keyboard shortcut hints. Closes #43 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

revert: remove CoDA splash screen, restore original welcome text

373d56f

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Revert "revert: remove CoDA splash screen, restore original welcome t…

9ca5cb9

…ext" This reverts commit 373d56f.

refactor: replace inline shortcuts with Ctrl+/ hint in splash screen

1eabee5

Now that the shortcuts help popup exists, point users there instead of listing individual shortcuts in the splash screen. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

datasciencemonkey mentioned this pull request Mar 8, 2026

feat: Tab-based terminal UI with optional tmux #38

Open

6 tasks

datasciencemonkey changed the title ~~feat: multi-tab terminals, splash screen, shortcuts help, release workflow~~ feat: multi-tab terminals, batch polling, security hardening Mar 8, 2026

datasciencemonkey self-assigned this Mar 8, 2026

datasciencemonkey and others added 4 commits March 8, 2026 08:14

fix: prevent terminal cutoff in Databricks Apps iframe

821d9f4

Use percentage-based heights instead of viewport units (100vh/100vw) so the terminal fits within the Databricks Apps iframe container without overflowing at the bottom. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

fix: prevent last terminal row from being clipped

21e1d20

Add 2px bottom padding to pane container so xterm.js fit addon has breathing room and doesn't squeeze in a row that gets cut off by overflow: hidden. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

datasciencemonkey merged commit 7181580 into main Mar 8, 2026

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feat: multi-tab terminals, batch polling, security hardening#46

feat: multi-tab terminals, batch polling, security hardening#46
datasciencemonkey merged 31 commits intomainfrom
feat/multi-tab-terminals

datasciencemonkey commented Mar 8, 2026 •

edited

Loading

Uh oh!

datasciencemonkey commented Mar 8, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Conversation

datasciencemonkey commented Mar 8, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Tmux Evaluation

Test plan

Uh oh!

datasciencemonkey commented Mar 8, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

datasciencemonkey commented Mar 8, 2026 •

edited

Loading