A second implementation of cst_agent_hooks_t next to the TUI: the turn runs on
a worker thread, the hooks publish events into a ring buffer that SSE clients
read, so the engine itself needs no changes.
- src/net.c, include/cst_net.h: POSIX/Winsock sockets, non-blocking connect
- src/http_srv.c, include/cst_http.h: HTTP/1.1, keep-alive, chunked streaming,
body caps (413), Expect: 100-continue, connection cap, exact routing
- src/web_md.c, include/cst_web_md.h: streaming markdown -> sanitized HTML
(tag/attribute allowlist, javascript: URLs and off-site images dropped)
- src/webui.c, include/cst_webui.h: event ring + SSE broadcast, all routes,
token (Bearer/Cookie/query) and loopback Host checks, 3 s auto-deny when no
client is attached
- src/webui_stub.c, CST_WEBUI=0 / CST_BUILD_WEBUI=OFF: build without the WebUI
- web/: no-build front end (transcript, approvals, todo, sessions, image
upload, status bar)
- docs/webui.md: engine API v1 - events, requests, security model
- tests/test_webui.c, scripts/e2e_webui.sh: unit tests plus an end-to-end run
driven by a recorded SSE stream (no API key needed)
- src/main.c: --web --web-port --web-host --web-token --web-dev --web-open
and CST_WEB_PORT/HOST/TOKEN/ROOT
An empty POST body is now accepted without Content-Length (RFC 9112 6.3) so
curl-driven clients can reach cancel/undo/compact/quit; CMakeList's core tests
learned about sashidown and test_webui, and CST_WEBUI=0 defines CST_NO_WEBUI.
Images
- vision gate: text-only models get a note instead of image parts and no
view_image tool; unknown models retry once without images on HTTP 400
- paste: Ctrl+V and /attach paste read the clipboard (wl-paste, xclip,
pngpaste/osascript, Win32 PNG or CF_DIB converted to PNG); pasting image
file paths attaches them
- MCP image content is stored in the session and sent with the tool result
- attach: rel path validation, base64 decode, /retry keeps images
Model registry
- built-in src/models_builtin.json embedded at build time, merged with
<config>/models.json and cached GET /models metadata (context, vision,
pricing); most specific rule wins per field
- /model labels, /status source, --list-models [provider]
Cache and cost
- stable request prefix (frozen tools, notes as messages), DeepSeek prefix
completion, OpenAI/Anthropic cache hints, /cost and hit rate in the status
os_win.c needs cst_buf_* / cst_utf8_valid from util.c after os_compat was
added to the small replay CMake targets. Release packaging only needs
cst-agent.exe, so bootstrap_windows.sh builds that target alone.
gcc -O0 keeps unused cst_test_util.h helpers that need os_*; clang GC'd
them so only the gcc CMake step failed. Prefer ghfast/ghproxy.net for the
llvm-mingw tarball (gitclone 500 / github unreachable on the runner).
os_temp_dir() used $TMPDIR or "/tmp" without checking either. On Termux
/tmp usually does not exist (or SELinux denies it) unless TMPDIR points at
$PREFIX/tmp, so plugin and MCP temp files failed and shell children that
need a temp file (heredocs) broke.
* os_temp_dir() picks, once, the first of $TMPDIR, $PREFIX/tmp, /tmp,
/var/tmp and ~/.cache/cst-agent/tmp where a file can really be
created; if none works it keeps the old answer
* os_temp_dir_export() at startup writes the choice back to TMPDIR, so
shell children and the sandbox's writable temp dir agree
* tests/test_tmpdir.c covers the fallbacks in fresh forks
Build
* cross build switches to pkgsCross.ucrt64 (shell-win.nix); curl (Schannel),
winpthreads and ncurses 6.6 are linked statically, so the release is
cst-agent.exe + busybox.exe (busybox-w32 Unicode) with no extra DLLs
* windres embeds a manifest with activeCodePage=UTF-8 and a version resource
* ncurses 6.6 Windows console driver patches (mouse button state, A_DIM,
wide-char declarations): scripts/patches/
* scripts/bootstrap_msys2.sh builds the same release natively in MSYS2
UCRT64; PR #1's MINGW64 notes now point there
* vendor/tre-regex (musl's TRE) provides <regex.h> on MinGW
UTF-8
* paths cross the system call boundary as UTF-16 (*W APIs); console code
pages set to 65001 and restored on exit; files are read and written in
binary mode
* child output that is not valid UTF-8 is decoded from the console, OEM or
ANSI system code page
* read_file hides CR; edit_file, apply_patch and write_file keep CRLF line
endings and a UTF-8 BOM
OS layer and processes
* os_dir_* and cst_fnmatch replace the POSIX-only directory walks in
subagent, plugins, skills, undo and fs_tools; realpath / path_under and
symlink rejection work on Windows
* every child goes through CreateProcessW with its own environment block
inside a Job Object, so timeouts and Esc end the whole process tree
Sandbox (auto mode, "auto · lowil")
* run_shell runs with a restricted Low integrity token; the workspace gets
an inheritable Low label once, the sandbox TEMP is labeled Low, and the
credentials file gets a no-read-up label
* drive roots, the profile and system folders are never labeled
* network commands still ask, since Low IL does not block the network;
Access denied and MSYS2's 0xc0000142 offer a rerun outside the sandbox
* /sandbox lists labeled folders, /sandbox reset-labels restores them
TUI
* raster console fonts are switched to Consolas / NSimSun while running
* the home logo falls back to text when the console font lacks U+2580
* mouse drag copy goes to the Windows clipboard
Distribution
* scripts/install_windows.ps1 installs a Gitea release into
%LOCALAPPDATA%\Programs\cst-agent and adds it to the user PATH;
cst-agent-update.cmd reruns it; scripts/release_windows.sh uploads the
zip with the token taken from the environment
* scripts/run_windows.bat is gone; docs/README-windows.md is rewritten
Tests
* new test_lowil, test_win_utf8 and test_os_dir; tests made portable
(cst_test_util.h)
* scripts/win_test.sh and scripts/winvm/ run the suite on English and
Chinese Windows Server VMs as Administrator, a standard user and a
Chinese user name: 29/29 on all six
- Drag, double-click (word) and triple-click (line) selection in the log,
auto-scroll at the edges, soft-wrapped lines joined on copy.
- sashidown ANSI renderer: delimiter runs with flanking rules, so
intraword underscores (test_apply_patch.c) stay literal; unmatched
* _ and backticks are shown as-is; * and _ do not close each other.
- tests: test_textsel, test_markdown.
Tools
- Table-driven tool registry with permission classes and default/minimal
profiles; new tools: edit_file, list_dir, glob, grep, delete_file,
move_file, todo_write, web_fetch, ask_user (plus read_file paging).
- Built-in Myers diff; write tools return unified diffs.
- Persistent permission rules (.agent/permissions.json), per-turn undo
snapshots (.agent/undo), AGENTS.md project notes, auto-compact at 80%
of the model context, cancellable run_shell with process-group kill.
TUI
- Table-driven slash commands: /provider /key /effort /status /tools
/permissions /yolo /undo /retry /diff /export /copy /rename /delete
/init /max-steps /todo, with / and @ completion.
- Permission modal with diff and prefix rules, ask_user modal, todo
panel, header with model/effort/context, bracketed paste, line editing,
wide-char cursor, NO_COLOR and ASCII fallback; Esc never quits.
Startup and configuration
- API keys are entered in the TUI (hidden) and saved per provider in
<config>/credentials (0600); env variables are only a fallback.
- Last provider, per-provider model and reasoning effort are remembered
in <config>/settings.json; --effort/-e and /effort send
reasoning_effort (low|medium|high|max) to models that accept it.
- DeepSeek preset uses deepseek-flash / deepseek-v4-pro.
- Session flags --new/--continue/--resume/--list-sessions, --yolo,
--confirm.
Compatibility and tests
- ncurses detection, macOS/Homebrew support, make install, XDG config
dir, POSIX cleanups; Gitea CI (gcc/clang/asan/musl/macOS).
- Unit tests for diff, fs tools, registry, undo/perms and config;
e2e fixtures multi_file_refactor and ask_or_todo; vendored cJSON.
WHC
XYZ