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.
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.
WHC