Frontier Refactoring Project (develop branch status)

Last updated: 2026-06-07

Frontier is being brought back to life. This project is modernizing the classic UserTalk scripting environment and object database into a contemporary cross-platform tool. The headless CLI is now fully functional — you can explore databases, write scripts, debug UserTalk programs, and serve web applications, all from the command line. Two debugger interfaces ship in the same binary: a machine-driven NDJSON protocol that any IDE or external tool can drive (--protocol), and a full-screen terminal UI (--debug-tui) for direct interactive use. A portable terminal window-manager substrate (boxen) underlies the TUI and is the foundation for the upcoming Phase C native REPL. A native GUI application with a documented API is being planned in parallel. The goal: preserve everything that made Frontier powerful while making it accessible to a new generation of developers, tinkerers, bloggers, writers, podcasters, and product builders.

Latest Release: v1.0.0-alpha.7 (Feb 16, 2026)

Download: GitHub Releases

Zero test failures, real threading, and parallel test execution. This release brings major infrastructure improvements:

• 0 Integration Test Failures – 1,881 tests, all passing (was 755 failures two weeks ago)
• GIL-Based Threading – Real POSIX threads with a global interpreter lock and cooperative yield points
• NDJSON Protocol Mode – Persistent subprocess communication via --protocol flag; foundation for future GUI
• 8-Worker Parallel Tests – Full test suite runs in ~40 seconds (was 5+ minutes sequential)
• Per-Component Logging – Fine-grained control via FRONTIER_LOG=comp:level and --log flag
• Ranger-Style File Browser – Two-pane file browser with arrow key navigation for file.getFileDialog

Quick start:

[root]> user.inetd.config.http.port = 8080
[root]> user.webserver.responders.helloWorld.enabled = true
[root]> inetd.startOne (@user.inetd.config.http)
# Visit http://localhost:8080/helloworld in your browser

Overall Progress: 68% verb coverage (482/710 verbs), 22 processors fully implemented, 302 unit tests + 1,920 integration tests — 0 failures.

For comprehensive status details, see STATUS.md. For release details, see the v1.0.0-alpha.7 release notes.

Development Progress (Feb 16 - Apr 7, 2026)

Through the alpha.7 release window:

• Protocol-Based UserTalk Debugger (7 phases) — Full debugger accessible via the NDJSON protocol: set/clear/list breakpoints, step into/over/out, watchpoints with fire-on-change, conditional breakpoints with UserTalk expressions, multi-thread debugging with thread listing, and variable inspection at any scope. Enables any GUI or IDE to provide a debugging experience.
• Data-Loss Risk Hardening — Duplicate open guards prevent concurrent modification of the same database file, fread size validation catches truncated reads, migration locking prevents partial writes during v6→v7 conversion.
• databasedata Global Elimination (Phases 1-10) — All runtime save/swap/restore of the databasedata global eliminated from pack/unpack/save/load paths. Explicit DB handle threading throughout the wrapper layer. Zero runtime mutation achieved.
• Startup & Threading Fixes — GIL deadlock blocking HTTP callbacks resolved, 19 consistently-failing integration tests fixed, guest DB script execution stabilized.
• CLI Enhancements — system.environment.args exposes CLI arguments to scripts, sys.openUrl kernel verb, --browser flag for automation tools.
• Lint Infrastructure — clang-tidy (bug-finding checks), ruff (Python), shellcheck (bash) configs with Makefile targets.

In Development Since alpha.7 (Apr 7 - Jun 7, 2026)

The two months since alpha.7 have focused on interactive debugging and the substrate for a native REPL. Headlines:

• Boxen — portable terminal window manager (Phase A) — A termbox2-based window/pane substrate with modal windows, cursor positioning, mouse events (including Cmd-double-click), and a stable input/draw callback model. Shared between the TUI debugger today and the planned Phase C REPL. Lives in portable/boxen/.
• TUI Debugger — --debug-tui (Phase B) — A full-screen interactive debugger for UserTalk scripts. Two-pane source/state view with a keybind footer, F-key step/continue/breakpoint controls, conditional breakpoints (Shift-F9), watchpoints (modal + Cmd-double-click on a local identifier), and a : scratch-eval pane that runs script/eval against the suspended frame. Hooks the lazy-attach transport so menu-triggered code that runs on thread.callScript threads (previously invisible to LLDB) is now debuggable inline. See docs/TUI_DEBUGGER_GUIDE.md for usage and docs/TUI_DEBUGGER_ARCHITECTURE.md for internals.
• Lazy-attach debugger transport (PR #722) — Global atomic transport pointer with a drain-before-free teardown contract. Lets the TUI (and any future in-process attacher) hook the debugger runtime safely, without the use-after-free surface that prevented WebSocket-attached debugging.
• String safety — copyctopstring clamp — Length-validated copy-to-Pascal-string with explicit truncation surfaced at user-facing callsites. Closes a class of latent overflow bugs in the legacy C surface.
• Test infrastructure — Test staging via cp -R with md5 drift check protects the canonical databases/ from test mutation. File-level YAML metadata (sequential, needs_guest_dbs, protocol_mode) drives parallel runner behavior. PTY-driven Python lifecycle tests for TUI clean-exit verification.

Current Test Status: ~753 unit tests + 2,186 integration tests passing (21 known-baseline integration failures in html/tcp/startup, unchanged across the window).

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Quick Start

Prerequisites

• macOS (12.0 Monterey or later recommended)
• Xcode Command Line Tools: Install with xcode-select --install

Build and Run

# 1. Clone the repository
git clone https://github.com/jsavin/Frontier.git
cd Frontier

# 2. Build the CLI (creates universal binary for arm64 + x86_64)
make -C frontier-cli

# 3. Verify the build works
./frontier-cli/frontier-cli -e "1 + 1"
# Output: 2

# 4. Launch the interactive REPL
./frontier-cli/frontier-cli
# Type UserTalk expressions, use /help for commands, /exit to quit

Run Tests

# Unit tests (C test suite)
./tools/run_headless_tests.sh

# Integration tests (Python/YAML-based UserTalk tests)
cd tests && make test-integration

# Both unit and integration tests
cd tests && make test-all

Debug a UserTalk Script

Frontier ships two debugger interfaces in the same binary:

# Interactive: full-screen terminal UI with F-key controls
./frontier-cli/frontier-cli --debug-tui

# Machine-driven: NDJSON over stdio for IDEs and external tools
./frontier-cli/frontier-cli --protocol

The two modes are mutually exclusive — pick one per session. The TUI is TTY-only (it opens /dev/tty directly); --protocol runs over piped stdio.

TUI keybinds at a glance: F5 continue, F9 toggle breakpoint, Shift-F9 conditional breakpoint, F10 step-over, F11 step-into, Shift-F11 step-out, : open scratch-eval pane, q quit. Cmd-double-click a local identifier in the script pane to set a watchpoint or inspect its value.

Full reference: docs/TUI_DEBUGGER_GUIDE.md. For the NDJSON protocol surface, see docs/CLI_USAGE_GUIDE.md.

Next Steps

• Getting Started Guide - Complete newcomer guide with detailed setup
• CLI Usage Guide - Comprehensive CLI and REPL documentation
• TUI Debugger Guide - Interactive --debug-tui reference (keybinds, workflows, limitations)
• Testing Guide - Writing and running tests
• Palette Test Harness - Four-layer (L1-L4) test model for the REPL slash-menu palette

MySQL Client Setup

Frontier links against the MySQL/MariaDB C client library for legacy database integration. Prebuilt binaries are no longer stored in the repo.

• macOS / Linux: run scripts/build_mysql_client.sh to fetch and compile MariaDB Connector/C into Common/MySQL/ (or override the install location via MYSQL_CLIENT_PREFIX). The script builds both arm64 and x86_64 static libraries and drops compatibility symlinks (libmysqlclient.a and include/mysql/).
• Windows: legacy Visual Studio project files have been removed. Updated instructions will accompany the next iteration of Windows support.

See docs/mysql_client_setup.md for detailed guidance.

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Repository Layout (Quick Tour)

Frontier/
├── app_resources/        # App bundles/resources (Frontier, OPML, Radio)
├── Common/               # Legacy Frontier sources/headers
├── databases/            # Frontier.root + guest databases (test fixtures)
├── docs/                 # Extensive documentation of Frontier's design and the UserTalk language and verbs
├── portable/             # Portable runtime layer + stubs
├── frontier-cli/         # Multi-arch CLI build
├── tests/                # Cross-platform C test suite
├── tools/                # Build tools (kernelverbs_parser, strings_compiler)
├── planning/             # Roadmap, ADRs, decisions, quickstarts
├── codex_sessions/       # README pointer (actual logs in codex-sessions branch, no longer used)
├── reports/              # Static analysis and progress reports (generated)
└── usertalk-scripts/     # Text file export of all the core UserTalk scripts in Frontier.root

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Planning & Documentation (Read These First)

• planning/INDEX.md – roadmap, active workstreams, ownership
• planning/phase_overview.md – overview of all phases
• planning/architectural_decision_records/ – ADRs for key technical decisions
• planning/Frontier_Refactoring_Plan.md – original modernisation plan

For in-flight work/status, see STATUS.md. Historical session context lives in planning/progress_reports/README.md.

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Contribution Workflow

Frontier development follows a structured workflow designed to maintain code quality and enable parallel development:

1. Read CONTRIBUTING.md for branching, commit, and testing expectations.
2. Branch from develop and keep changes small. Use feature branches in separate worktrees for non-trivial work:

   cd /Users/jake/dev/jsavin/Frontier
   git worktree add ../Frontier-<feature-name> -b feature/<feature-name>
   cd ../Frontier-<feature-name>

3. Update/consult planning docs before coding (PRs reference the appropriate ADR/decision where possible).
4. Run targeted tests locally; note known failures when applicable:

   ./tools/run_headless_tests.sh              # Unit tests
   cd tests && make test-integration          # Integration tests

5. Update docs and tests alongside code; add Codex notes if significant.
6. Open PRs against develop (multi-arch + headless tests should remain green). Use the /doit workflow for feature development:
   • Creates feature branch in worktree
   • Designs implementation plan (with user approval)
   • Implements with specialized agents (in parallel where possible)
   • Writes and runs tests
   • Creates PR with background monitoring

For detailed workflow guidance, see docs/WORKTREE_WORKFLOW.md and docs/PR_MONITOR_BLOCKING_ISSUE.md.

Key Development Principles

Security and Testing:

• Security hardening built in from start (SSRF protection, DNS rebinding, data-loss guards, length-clamped Pascal-string conversion)
• ~2,940 tests (~753 unit + 2,186 integration) running in 8-worker parallel, with 21 known-baseline integration failures tracked character-for-character
• Integration tests required for all verb implementations; PTY-driven lifecycle tests for TTY interfaces

Thread Safety and Database Integrity:

• GIL-based cooperative threading with real POSIX threads
• databasedata global elimination complete — zero runtime mutation
• v6→v7 migration validated, Y2038-safe 64-bit timestamps throughout
• Context guard pattern for safe concurrent database operations

For comprehensive status details, verb coverage, and milestone snapshots, see STATUS.md.

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Historical Progress

Historical session summaries live under planning/progress_reports/README.md.