Wire hermit_getenv across the engine, rebrand WebUI/systemd/docs, and
add apps/desktop (Tauri 2 + React) with a DeepSeek-Harness-like UI.
Qt app/ is frozen; full libcstcore FFI is scaffolded behind --features engine.
Co-authored-by: Cursor <cursoragent@cursor.com>
The settings dialog could pick a preset, a model and a key and nothing else.
Two things were missing: a provider the presets do not know, and what the
model is asked to do while it answers. Both live under "Advanced options"
now, next to the entry they belong to.
Custom providers (engine)
- cst_models_user_set_provider() / cst_models_user_drop_provider() write the
engine's own user layer, <config>/cst-agent/models.json:
{"providers": {"myllm": {"api_base": ..., "key_env": ...,
"default_model": ..., "models": [...]}}}
and reload the registry, so the provider is at once in the provider list,
in the wire models[] and in the CLI's /provider -- the file a hand-written
override would go into is the same one, so the GUI and an editor agree.
The name is checked (1-31 of letters, digits, '.', '_', '-'), a preset's
name overrides that preset (a self-hosted endpoint, a proxy), everything
else in the file (model rules) is kept, and a file that is not a JSON
object is never overwritten. Dropping only removes the user's own entry.
- AgentCore::providers() gained "custom" (source == "user"), and
addProvider() / removeProvider() drive the two calls above.
Model parameters (engine + wire)
- cst_agent_config_t and cst_llm_request_t carry temperature, top_p and
max_tokens. 0 means the field is not sent at all -- an absent field is the
provider's own default, which "temperature": 0 is not (deterministic
decoding is a real choice), so cst_llm_build_body() only adds what was set.
tests/test_llm_body.c:test_gen_params pins both halves.
- settings.json keeps them per provider ("params": {...}) via
cst_settings_remember_params(); cst_settings_remember() carries them along
with the provider choice, and cst_agent_create() reads them, so a CLI or
TUI run sends what the window was set to. An all-zero config (the CLI)
leaves what the GUI saved alone.
- AgentCore::genParams() / setGenParams(), and useProvider() applies both the
remembered parameters of the provider it lands on and a base URL that was
edited in the dialog.
The dialog
- Rewritten around one scrolling body with a fixed footer: a long model list
used to push the key field and the buttons out of the dialog. The model
chips are filtered (a filter field appears past twelve) and capped at 40
with "... +N more", which is what a router with hundreds of models needs.
- "Advanced options" folds out the provider entry (name, base URL, key
variable, default model, models; Save provider / Remove from models.json)
and the model parameters (temperature, top-p, max tokens; empty = not
sent). The fields follow the picked provider and are what gets saved, so a
hand-typed edit is never lost to a stale property.
Verified: --uitest 67/67 (15 new checks: parameters round-trip through the
engine, a provider added through the form and removed again, a bad name
refused, a preset not removable), --selftest, ctest cst-app-selftest, and
make check with the new body test.
Version 0.8.15.
mode = coding
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.
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.
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
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.
