A TUI run against an unreachable endpoint failed with only 'fetch failed':
undici wraps transport failures in a bare TypeError whose diagnosis lives
on .cause, and every diagnostic seam rendered only error.message. The
readline front door additionally rendered failed turns as pure silence.
- dsh-llm: new errorChain(value) renders the full cause chain and
AggregateError members with circular/hostile-coercion containment.
- llm-deepseek: pre-response transport failures throw LlmError('NETWORK')
naming the endpoint and chaining the fetch TypeError; aborts keep their
DOMException so the loop still classifies them as cancellation.
- agent-loop: durable turn/end error messages and logger warnings render
through errorChain; local renderThrown copies removed.
- ui-stdio: failure turn/end reasons now render ([turn failed <code>],
[turn aborted], [turn rejected], output-token-limit); startup-failure
logs use errorChain.
- ui-tui: agent/error notices and the startup-failure line use errorChain.
Name the runnable leaf for the line-oriented front door it owns, matching the existing tui-agent and acp-agent organization. Move the complete config, Code Mode overlay, tests, metadata, and generated composition graph together, then update every loader path and repository reference.
Keep the shared model identity independent of its terminal front door by phrasing the persona as a coding-agent role rather than retaining the retired leaf name. Regenerate graph and tool catalogs and re-record each affected bilingual pair so derived documentation cannot point at the removed path.
Master unifies every live agent with its exact SessionId and moves declarative startup failures to agent-loop/config-start-failed. Keeping the branch’s AgentId label binding would let the TUI target the wrong lifecycle after reload and would miss asynchronous resume failures.
Resolve that contract migration by giving the selected terminal front door the same generated or resumed SessionId as agent-core, mounting the front door first, and entering fullscreen only after the matching root appears. Refresh the source-derived catalogs and keyless terminal goldens so Code Mode, workflow, Cordis-tool, and transient UI scenarios all exercise the merged identity model.
Model responses, replayed session data, tool presenter output, question metadata, configuration, and diagnostics all cross into ANSI-aware pi-tui renderers. Passing their C0 or C1 controls through unchanged lets an otherwise ordinary transcript emit OSC, CSI, cursor, or title operations in the user terminal.
Introduce one displayText boundary that preserves line-feed layout but renders every other C0/C1 control as visible \\xNN text before application styling is applied. Route transcript blocks, streaming output, tool cards, diffs, plans, dialogs, headers, cwd/title data, notices, errors, and pre-mount startup failures through that boundary while leaving pi-tui and the theme responsible for legitimate terminal control sequences.
Pin the contract at three levels: a settled headless-terminal golden spans the main untrusted display sources, unit coverage checks the pre-fullscreen failure path, and the real Loader/PTY conversation streams hostile OSC, cursor, and C1 probes and proves only their inert textual forms reach the terminal stream.
The palette used absolute 256-color indices (`38;5;252`, `48;5;236`, …)
that terminals never remap to the active scheme: near-white body text
vanished on light backgrounds and fixed dark bubble fills put default
foreground text on dark blocks. Rebuild it from the standard 16-color
ANSI foregrounds plus SGR attributes, keep body text on the terminal
default foreground, replace filled background bubbles with foreground-only
left-gutter bars, and use reverse video for the active selection so every
grouping reads on any color scheme.
Move the interactive pi-tui front door into @deepseek-ai/dsh-tui while keeping @deepseek-ai/dsh-stdio line-oriented for pipes. Select the terminal package in the demo app, preserve logger ownership, and cover the production Loader composition with a PTY smoke test.
Tianyi Cui
Yichen Jiang
Turtle