Wisp 0.2.0rc2 release decision and checklist

Status: release preparation, September 16, 2026. This PR prepares the candidate; it does not create a tag, publish packages, or remove Textual. Stable remains 0.1.0; the latest published candidate at preparation time is 0.2.0rc1.

This is the historical RC2 release checklist. It records the renderer policy and validation work at that release; the current frontend policy is documented in the CLI reference. Textual commands below describe that earlier candidate and are no longer available in current development.

Renderer decision

The release owner approved an RC trial of Rust as the native-install default, superseding the September 3 experimental-default hold in #470 for this candidate. This is an explicit product decision under #456, not an inference from completed packaging or feature issues.

• wisp, wisp tui, and wisp --mode tui default to auto.
• On macOS/Linux, an installed distribution declaring wisp-tui selects Rust. A pure wheel or source installation without that declaration selects Textual. No executable is discovered via PATH.
• Native release targets are macOS arm64 and Linux glibc 2.28+ x86_64. Intel macOS, Linux arm64, musl/Alpine, and Windows retain the Python route; Windows remains best-effort, not CI-certified.
• Explicit CLI flags override WISP_TUI_RENDERER; the environment overrides auto. --line remains explicit. A development WISP_RUST_TUI_BINARY override selects Rust in auto mode on macOS/Linux and is validated normally.
• A declared but missing, non-executable, corrupt, incompatible, or failing Rust binary remains an actionable error. There is no fallback after Rust selection. Users select Textual explicitly with wisp tui --renderer textual or WISP_TUI_RENDERER=textual.
• Textual remains installed, tested, and maintained for compatibility and critical fixes. New frontend features prioritize Rust. Removal and stable promotion require separate decisions.

Python retains runtime, safety, authentication, and persistence authority. Print, JSON, RPC, and SDK contracts are unchanged by renderer selection. Package versions remain exactly paired: Python 0.2.0rc2, Cargo 0.2.0-rc.2.

Accepted RC differences and promotion blockers

Rust does not yet implement transcript search, built-in transcript copying/drag selection, clickable Markdown links, or Textual’s integrated update/restart dialog. Terminal-native copying is available subject to mouse-capture settings. Composer clipboard support is separate. The Textual fallback remains available when these differences affect a workflow.

Any reproducible loss of session content, incorrect approval/trust/cancellation behavior, startup failure on a claimed native target, or terminal/process cleanup regression blocks release acceptance. Full history is retained without a transcript cap: startup cost and memory grow with the corpus. Large messages may use plain-text rendering. Rust’s implementation language is not performance proof.

Before stable promotion, record representative terminal and multiplexer feedback, copying and accessibility limitations, support burden, and matched Textual/Rust input-to-frame, CPU, startup, and memory measurements. The installed RC smoke below is a narrower release check, not that comparison.

Prepublication checks

• Exact PR head has terminal green CI and no actionable review threads.
• Python format/lint/mypy, generated themes, immutable protocol schemas, and full tests pass.
• Rust formatting, Clippy, full workspace tests, build, and Python/Rust handoff tests pass.
• Pure wheel, sdist, and native candidate wheels pass metadata/version/content verification.
• Native-wheel lifecycle passes on every claimed target: automatic selection, explicit Textual, native-to-pure replacement, corrupt/non-executable failure, offline reinstall, and uninstall.
• Each native target records installed startup with empty history and 10,001 saved messages, submits a new fake-provider prompt after hydration, exits, and restores terminal attributes.
• Docs build passes; release notes explain renderer selection, platform scope, and rollback.

The wheel CI runs scripts/verify_rust_tui_install_lifecycle.py. Its JSON evidence includes an empty session and long_history measurements. The synthetic large fixture contains 2,500 complete user/assistant/read-tool/result cycles (10,000 records) plus a final readiness sentinel. It is generated outside the startup timing. ready_frame_seconds measures observed readiness through the installed launcher; max_rss_bytes is the maximum reported child-process RSS, not the sum or concurrent peak of the process tree. Timings depend on machine and load and are observations, not universal thresholds.

To reproduce a long-history measurement in an isolated installed native environment:

/path/to/environment/bin/python scripts/smoke_installed_rust_tui.py \
  --wisp /path/to/environment/bin/wisp \
  --session-dir /tmp/wisp-rc2-history-probe \
  --history-messages 10000

Use a disposable session directory. This submits only a fake-provider prompt; no API credentials are needed. Candidate CI artifacts are prepublication evidence, not proof of PyPI availability.

Local candidate evidence

Measured September 16 on macOS arm64 with Python 3.12.2, using the installed native candidate wheel outside the source package. The full Python test suite was running concurrently; these are single observations under load, not a controlled renderer comparison.

Both workloads submitted a fake-provider prompt, received its response, exited successfully, and restored terminal attributes. The complete local lifecycle also passed default selection on native and pure installs, explicit Textual routing, absent Rust after pure replacement, non-executable and corrupt Rust failures, native restoration, offline reinstall, and uninstall. Unit tests separately cover a native distribution declaring a missing executable. Wheel metadata/content parity verification passed. The native wheel measured 5,703,473 bytes; its stripped binary measured 11,938,416 bytes.

The PR’s candidate-wheel CI supplies Linux x86_64 evidence using the same script. Published PyPI installation and cross-version downgrade remain postpublication work.

Publication and postpublication acceptance

After the release PR merges, publishing requires a separately authorized v0.2.0rc2 tag through the existing release workflow. Do not manually upload partial artifacts or substitute source-build tests.

• Verify exactly one sdist, one pure fallback wheel, and two native wheels were published.
• Verify checksums, SBOMs, provenance attestations, package/native versions, and protocol identity.
• Install wisp-ai==0.2.0rc2 from PyPI without Cargo on each claimed target; repeat default-launch, prompt, session resume, explicit Textual, and lifecycle checks outside the source checkout.
• Record immutable artifact links and measurements; update the upgrade guide’s publication status.
• Dogfood the published candidate and record remaining terminal/accessibility issues under #456.

For a frontend regression, select Textual explicitly and retain the session files for diagnosis. Reverting the default requires another reviewed change; downgrading the entire package is not needed just to switch frontends. Cross-version native rollback evidence remains separate from this PR’s same-version native/pure replacement checks. Never delete or migrate user sessions as a rollback step.