chat.md

title	Chat
description	The TUI, keys, slash commands, one-shot mode, and streaming.

aster in a repository opens the chat TUI. Everything else is optional flags on top of it.

aster                                # TUI in the current repo
aster "why does the build fail?"     # one-shot: print and exit (--print / -p)
echo "explain this repo" | aster     # piped stdin is the prompt
aster --continue                     # resume this repo's latest session
aster --resume [ID]                  # pick a session, or resume one by id
aster --session ID "next question"   # persist into a named session
aster --messages-json history.json   # caller owns the transcript (- for stdin)
aster --compact --messages-json h.json   # fold history into a summary, print it
aster --stream                       # NDJSON events out, approval replies in
aster --no-tools                     # plain chat, no read/search/edit
aster --no-mcp                       # start instantly; /mcp connects later
aster --allow-edits                  # let a scripted turn edit files
aster --permission-mode plan|manual|auto|edit|yolo

Chat, review, and fix also take --model and --effort off|low|medium|high|xhigh|max|ultra.

Keys

Key	Does
enter	Send; while a turn runs it queues the message
esc	Interrupt the running turn; esc esc quits
shift+tab	Step to the next permission mode
ctrl+j	Newline without sending
ctrl+o	The /switch panel
@	Mention a repo file; images and documents attach as content
↑ ↓	Move the cursor, then step through past messages

Slash commands

Command	Does
/switch	Thinking, mode, effort, model, provider in one panel
/model [id], /m	Switch model or open the picker
/provider [id|url], /p	Switch endpoint, then pick a model
/mode [name]	plan, manual, auto, edit, yolo
/effort [level]	Set or cycle the reasoning budget
/thinking	Print the model's thinking in full or not
/yolo	Toggle yolo (guardrails off, red theme)
/mom [resume]	Show the mom.yaml routing state; resume re-arms it after a manual /model
/resume, /r	Reopen a saved session
/clear, /c	Start fresh
/compact	Fold earlier turns into a summary
/status	Session, model, context, token usage
/diff, /d	Uncommitted changes
/mcp	MCP servers and their tools; connects them if --no-mcp skipped it
/skills	Pick a skill to load
/memory	What Aster remembers here
/remember <text>	Save a fact to memory
/theme	Open the theme picker; previews live as you arrow through
/welcome	Show or hide the session header, saved to ui.welcome
/goal <condition>	Loop turns until a judge model says the condition is met
/help, /quit	The list above; exit

Installed skills that declare a command also appear as slash commands, for example /write-tests.

Themes

/theme opens a picker that previews live as you arrow through; Enter saves the choice to ui.theme in aster.yaml. Built-ins include dark, light, midnight, forest, dracula, catppuccin, nord, gruvbox, solarized, synthwave, github-dark, monokai, one-dark, aster-ocean, aster-ember, and aster-orchid. Custom themes are YAML files dropped into ~/.aster/themes/ or .aster/themes/; they appear in the picker on the next launch.

Sixteen built-in palettes, switchable live with /theme in the session. Each swatch below uses the exact background and accent colors from the theme itself.

❯ default the default warm dark palette	❯ aster-ocean the signature aster deep-teal dark	❯ aster-ember warm charcoal, burning orange	❯ aster-orchid violet dark, magenta accent
❯ dracula purple and pink on dark slate	❯ catppuccin warm pastels on mauve	❯ nord cool blues on slate	❯ gruvbox earthy amber and orange
❯ solarized muted teal and blue	❯ synthwave neon pink to cyan	❯ github-dark GitHub's calm blue dark palette	❯ monokai classic Sublime/Monokai Pro palette
❯ one-dark Atom One Dark blues and mint	❯ midnight deep blue dark palette	❯ forest muted green dark palette	❯ light for bright terminals

Streaming for tools

--stream emits one JSON object per line. The desktop app and the VS Code extension both consume this format, and it is stable output, not a log:

aster --stream "summarize the failing test"

Approval prompts arrive as events on stdout; reply on stdin to approve or deny, which is how headless front-ends gate edits.