The engine can be embedded now instead of only driven from a terminal: the
same objects link into a Qt front end (app/) that owns a cst_agent_t inside
its own process -- no port, no token, no second process -- and that front end
now runs on the desktop and, engine-side, on the phone.
Capability metadata (include/cst_tools.h, src/tools/registry.c):
- cst_tool_def_t gains perm_name, platforms and available (a probe that
returns a reason), so a permission is addressable by name and a tool can
say why it cannot run here.
- cst_platform_name(), cst_tool_platform_ok(), cst_tool_available(),
cst_tool_meta_reload(), cst_tool_perm_name() and CST_PLAT_DESKTOP[].
- cst_tool_register() may take over a built-in name that is not runnable on
this platform, so a front end replaces it with its own implementation.
- the registry entries carry their class (delete_file -> "delete"), the
desktop clipboard tools carry a clipboard probe; find/active/run gate on it.
- /api/settings.tools[] exposes perm_name, platforms, available, why and the
declared parameters.
Engine as a library (Makefile, CMakeLists.txt):
- libcstcore.a from the CORE_OBJ set, and a CMake cstcore target shared by
the CLI and by app/ (-DCST_BUILD_APP=ON): the engine is compiled once.
- Android branch for the vendored sashidown: a per-ABI archive built with the
NDK's aarch64-linux-android24-clang wrapper, because CMake's compiler is
plain clang and keeps --target/--sysroot in its own variables.
Qt front end (app/, new):
- AgentCore wraps one cst_agent_t: turns run on a worker thread, every
cst_agent_hooks_t callback becomes a Qt signal, and the two hooks that need
an answer (on_permission, on_ask_user) block the worker until the GUI
replies; mode, approval and plan mode go through the engine's config.
- ToolProvider hands the front end's tools to the engine (owner "app:*"); the
Linux one is notification_send with a probe for notify-send/D-Bus.
- Main.qml: transcript, tool blocks, consent dialog (Deny/Once/Always ->
CST_PERM_*), ask_user, mode switch, Esc to cancel; --selftest stays
headless and runs the embedding checks without QML.
Android (scripts/, docs/android.md, new):
- scripts/build_third_party_android.sh builds static mbedTLS + libcurl for an
ABI (CA path /system/etc/security/cacerts); build_android.sh builds
cst-agent, libcstcore.a and the test binaries for the phone, can push them
and run the whole suite there.
- sandbox_exec.c keeps the plain exec path on Android: the seccomp supervisor
compiled in and the probe reported "seccomp", but writes outside the
workspace were not denied on the device -- claiming a sandbox that does not
hold is worse than reporting none.
- tests/test_diff.c compares layouts only against real GNU diffutils: toybox's
diff prints the same hunk header with its own hunk/context rules.
Tests: test_tool_meta (metadata, platform gate, probe reasons, takeover of a
built-in name) and test_embed (in-process embedding contract) are new; the
existing registry/llm_body assertions now follow availability. 38 test
binaries pass on the host, 36/36 on arm64-v8a Android 16, cst-app-selftest
passes in both the standalone app/ build and the repo build.
Version 0.8.7.
Working mode: --mode coding|general (CST_MODE, settings.json, /mode,
WebUI run settings). general swaps the default framing for a general
assistant one -- workflow, safety notes, tool wording (run_shell, the
subagents) -- and /status shows it; minimal (the paper profile) stays
byte-frozen. The prompt state carries the mode so a switch leaves a
system note in history.
Clipboard: clipboard_read / clipboard_write tools (16 MiB cap read,
default 64 KiB window; writing is a WRITE permission with a preview) on
pbcopy / wl-copy / xclip / pbpaste / wl-paste / xclip and the Win32
clipboard. In the TUI, /attach paste falls back to clipboard text when
there is no image on it.
PDF: a dependency-free text extractor (src/pdf_text.c): inflate,
Flate/ASCIIHex/ASCII85, PNG/TIFF predictors, layout-independent object
scan, object streams, page tree walk with inherited resources, content
lexer (Tj/TJ/'/" and the Td/TD/T*/Tm spacing heuristics), per-font
ToUnicode CMaps and inline images skipped. Encrypted files and pages
with no text layer are refused with the reason.
Attachments: /attach (a path or files dropped on the terminal) now take
images, PDFs and text. A PDF is stored as its text layer with the mime
still saying application/pdf and its page count; anything else has to be
UTF-8 text. Documents travel inline as text parts, so CST_NO_IMAGES and
text-only models no longer drop them, while images keep their old path.
Tests: test_pdf_text (plain, bare and zlib-framed Flate, inline image,
CID + ToUnicode, object stream, error paths), documents in test_attach,
inlined documents in test_llm_body, mode in test_config.
Process timeline: a run of consecutive thinking and tool calls is one
block that folds to a single line ("思考 4 次 · 工具 6 次"; while running
it shows the current action) and opens into a compact timeline, one row
per thought or call. Visible text, a note or the next prompt closes the
block; history and the live stream follow the same rule. show_thinking
now also applies while streaming instead of forcing thoughts open.
Layout: the avatar gutter and the flex-wrap that dropped it under long
answers are gone, so answer, process blocks, notes and composer share one
left edge. The text column and composer are both 720px (--content); the
rail and run panel grow with clamp() on wide screens. A rebuild after
each turn no longer replays every entrance animation, and the turn time
survives it. Message actions are icon buttons and only appear under text.
Images: a prompt's images sit above the bubble, right-aligned (one keeps
its shape, several are 152px rounded tiles) and open in a lightbox (Esc,
arrow keys). Images uploaded from the page show as thumbnails over the
composer and appear on the prompt as soon as it is sent.
Also: ?theme= is no longer overridden by app.js, the user bubble is
visible in the light theme, and the narrow top bar no longer wraps.
Sessions: rename, delete and search; /api/retry regenerates the last
answer, editing a prompt resends from there; /api/export downloads the
transcript as Markdown (cst_session_export_md). Session messages carry
note/tool_result markers, so a reload rebuilds the tool steps with
their arguments, output and exit status; subagent progress is shown.
Diff and settings: /api/diff shows the real diff; /api/settings covers
protocol, max_steps, tool switches and confirm; /api/permissions edits
the rules; sandbox status is reported. Session rename no longer reads
past a short title.
Commands: slash commands with completion in the composer (/model,
/provider, /new, /retry, /undo, /compact, /export, /diff, /init,
/skill and more), a Ctrl+P palette, Shift+Tab cycles the approval
mode, F1 or ? shows the keys. "Thinking expanded" is saved in the
settings (show_thinking), "expand all tool output" in the browser.
Extensions: GET /api/extensions lists MCP servers, plugins, skills,
agent roles and subagent runs; POST /api/extensions/reload and
/api/extensions/trust; a workspace switch reloads them. /api/init and
/api/skill run on the server (cst_init_prompt shared with the TUI).
Errors, statuses and [cst] notes are shown in Chinese with a readable
reason instead of rc=; a failed turn's error survives the reload.
Tests: scripts/e2e_webui_sessions.py, e2e_webui_workspace.py and
e2e_webui_ext.py, run from e2e_webui.sh.
Streaming: Chinese reasoning showed up garbled in the WebUI. The agent
loop now feeds visible/thinking text in runs instead of byte by byte,
and the WebUI holds an incomplete UTF-8 tail until the next chunk
(cst_utf8_hold_feed), so every think_delta/assistant_delta is whole.
src/provider_switch.c: model list fetch/cache, key verify-and-save and
provider switching moved out of tui.c and shared by TUI and WebUI.
WebUI API:
- GET /api/providers, GET /api/models[?refresh=1] (401 on a rejected
key, still listing built-ins), POST /api/provider, POST /api/key
(key checked against /v1/models, saved to credentials 0600, never
echoed in replies, events or logs)
- /api/config validates everything before applying, persists model,
effort and approval (not yolo), warns when effort does not apply;
plan_mode no longer forces read-only
- state: turn_usage, api_base, key_set/key_from, model_info,
effort_applies, sees_images, max_steps, tool_profile, perm_timeout;
permission events carry their timeout
Frontend: searchable model picker with refresh and manual entry,
provider picker and key dialog, effort/vision hints, toasts instead of
silent failures, Chinese error text, real protocol in the settings and
usage panels, approval countdown from the server's timeout.
Tests: utf8 hold unit test, scripts/e2e_webui_settings.py (fake
/v1/models, wrong key, switching, persistence, Chinese thinking) run
from e2e_webui.sh, scripts/tui_keys/provider.py.
Build: <fcntl.h> in tui.c, format-truncation in http_srv.c and /web.
WebUI:
- refuse cross-site requests (Origin must be the page itself) in the
default no-token mode: any page could POST approval=yolo and a prompt
- session/workspace/undo/compact/attach/model changes are 409 while a
turn runs (use-after-free, messages landing in the wrong session)
- ask_user returned "dismissed" at once instead of waiting
- cancel and shutdown wake a turn parked on a permission or question;
SIGTERM mid-turn no longer hangs or crashes
- a page opened while a question is pending still gets it;
Last-Event-ID resumes the stream; event seq matches the SSE id
- token mode: page assets load without the token, images via cookie
- --web-open works, --web-port/--web-token are validated
- frontend: gate keys ignored while typing, clear-images button,
reasoning no longer wiped while streaming
HTTP server: auth and size cap before reading the body, strict
Content-Length, NUL in url_decode, 413 on keep-alive, idle timeout,
absolute-form only without a leading '/', case-insensitive Connection,
header deadline, 400 for long request lines, unlink before close,
poll() instead of select(), SO_EXCLUSIVEADDRUSE on Windows.
Markdown sanitizer escapes quotes in attribute values.
/web: passes this session's provider/model/base/effort/approval (key
via the environment), keeps output off the TUI, shows the real URL and
keeps CURRENT on the TUI's session.
Tests: scripts/e2e_webui_ask.py, scripts/e2e_webui_http.py (run from
e2e_webui.sh), sanitizer quote test.
The front end is rebuilt on the design tokens the desktop app ships (surfaces,
color-mix borders, alpha hovers, accent): a 30-icon inline SVG sprite, dark and
light themes, layout switches as deep links (?side=0, ?panel=0, ?theme=light)
resolved before the first paint. The empty page is one line and leaves with the
first turn; the right rail keeps three cards - todo, file changes (+N -M) and
context (tokens, prompt cache hit rate). Both rails animate in and out, and a
collapsed rail widens its grid track to 0 instead of being removed, so the
transcript never slides into a zero-width column.
- src/webui.c: POST /api/workspace - re-root the agent at another directory
(permission rules, metrics, AGENTS.md follow) and start a session there, as
sessions live per directory; state also reports cached/cache_miss tokens
- src/agent_loop.c: cst_agent_set_workspace(), rebuilt prompt and re-measured
budget; the auto-compact threshold is 75% of the window (was 60%)
- src/tui.c: /web forks a WebUI next to the TUI - separate process and a new
session, because cst_webui_run() blocks and two writers corrupt one session
- src/os_compat.c, src/os_win.c: run_shell runs without a time limit unless
CST_SHELL_TIMEOUT asks for one, so builds and long clones finish
- src/main.c, include/cst_webui.h: one CST_WEBUI_DEFAULT_PORT for --help, the
docs and /web; Termux opens the browser through termux-open-url
- README.md, docs/webui.md, docs/env_openai.md: /web, /api/workspace, the new
state fields, the 75% threshold and the layout deep links
tests/e2e_webui.sh green (permission round-trip, token paths, --web-dev);
make check green.
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.
TUI keys: register both CSI and SS3 forms of the cursor/Home/End keys and
the xterm modifier sequences when terminfo lacks them, so an arrow sent in
the "other" form no longer turns into Esc + a typed letter. Up/Down move by
visual (soft-wrapped) row, and the draft survives a trip through history.
scripts/tui_keys drives the TUI in a pty to check all of this.
Images: text inside a multimodal content array is now a {"type":"text"}
part; DeepSeek rejected the bare string with HTTP 422. deepseek-flash
(and its deepseek-chat / deepseek-reasoner aliases) read images, so the
registry marks them vision; deepseek-v4-pro stays text only.
CI: models.c lost _DEFAULT_SOURCE in 0.7.0 and gmtime_r broke the musl
build; tests sleep with poll() instead of usleep for the same reason.
Landlock no longer handles TCP, the Seatbelt profile drops (deny network*),
and the seccomp filter stops refusing IPv4/IPv6 sockets. Sandboxed commands
run without asking in auto mode on every backend (Low-IL no longer asks for
network commands), and connection errors are not treated as sandbox blocks.
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
After a successful windows-cross build on main or v* tags, upload the zip
and .sha256 via scripts/release_windows.sh (creates/updates v$VERSION).
Prefer secrets.RELEASE_TOKEN; fall back to GITHUB_TOKEN. Skip on PRs.
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.
windows-cross died cloning busybox-w32 through a global gitclone.com
insteadOf (HTTP 502). Try ghfast/ghproxy/gitclone/github per repo instead
of forcing one proxy for every fetch.
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).
clang under strict C11 left strcasestr undeclared (returns int → pointer
truncation → SIGSEGV). Parse Content-Length portably; keep -Werror on
make check. Drop Nix for windows-cross (root /nix fails) and use pinned
llvm-mingw UCRT instead; Alpine musl gets linux-headers for audit.h.
test_subagent segfaulted in the Docker runner: the fake SSE handler took
user + strlen(user) - 1 with an empty user string. Guard JSON access and
format the child report with an empty-safe last character. Remove the
sanitizers job entirely (if: false still queued it and blocked the runner).
- Replace actions/checkout (pulls from github.com) with scripts/ci_checkout.sh
fetched from this Gitea over raw/commit.
- Remove the macOS job (no runner).
- Disable sanitizers until the Docker runner has SYS_PTRACE; it was wedging
the only slot with AddressSanitizer:DEADLYSIGNAL.
- Add windows-cross: Nix UCRT mingw via TUNA, bootstrap_windows.sh, verify
dist/cst-agent-*-windows-x86_64.zip. Third-party git clones go through
gitclone.com.
The sanitizers job wedged the only runner by printing AddressSanitizer
DEADLYSIGNAL forever (Docker without SYS_PTRACE). Concurrency now cancels
in-progress jobs on a new push, and make asan is wrapped in timeout -s KILL
480 with shallow ASAN_OPTIONS.
Also copy the path with memcpy after the length check so -O1 asan builds
do not warn about snprintf truncation into OS_PATH_MAX.
CI passes CFLAGS=-Werror on the command line; that wiped the library's
CFLAGS ?= ... -Iinclude -Isrc, so fsm.h could not find sashidown.h.
Always append the include paths via override CPPFLAGS.
Install was pulling bookworm packages from deb.debian.org; the domestic
Gitea runner crawls that for minutes. Rewrite sources to TUNA before
apt-get/apk, with CST_CI_MIRROR to override.
With Yama ptrace_scope=2 and no CAP_SYS_PTRACE, process_vm_readv and
/proc/<pid>/mem both fail, so sc_decide cannot read path strings and every
workspace write gets EACCES. The old probe only checked the USER_NOTIF
round trip, so CST_SANDBOX=seccomp and the forced-seccomp test pass looked
available and then failed on the first write.
sc_can_peek() forks a child, places a marker on its stack, and retries the
same sc_peek path. sc_probe() now needs that too, so those hosts fall back
to none (or keep landlock) instead of a silent deny-all sandbox.
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.
Query CSI ? u at startup and push the disambiguate flag on the alternate
screen when the terminal answers; CSI u reports are mapped back to legacy
input (Shift/Ctrl+Enter insert a newline, Ctrl+Backspace deletes a word).
Ctrl/Alt+Left/Right move by word, Ctrl/Alt+Delete delete the next word.
Our define_key codes move above the range ncurses uses for terminfo
extended keys.
- Child installs a seccomp filter with a listener; a supervisor thread
resolves the path of write-type syscalls (cwd, dirfd, .., symlinks,
/proc/self, /dev/stdout, both ends of rename/link) and answers
CONTINUE or EACCES; IPv4/IPv6 sockets are refused
- Probe order Landlock -> seccomp -> none, checked in a throwaway child;
CST_SANDBOX=landlock|seccomp|off
- curl connect failures count as sandbox refusals
- test_sandbox runs the detected sandbox and forced seccomp, with escape,
symlink, rename, link, chmod, stdout, ENOENT, background and network cases
- Docs: platform matrix, limits (not a security boundary, Yama and
background jobs)
- bootstrap_termux.sh installs pkg-config/binutils, builds with make,
runs the tests and installs into Termux's $PREFIX/bin.
- Makefile drops -lpthread on Android (pthreads are in bionic libc).
- TUI assumes UTF-8 on Android: nl_langinfo needs API 26, Termux
targets 24. All sources compile for aarch64-linux-android24 (NDK 27).
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