gdd-bandit-reset

name	gdd-bandit-reset
description	Confirm-then-reset the per-(agent, bin, delegate) bandit posterior - backs up .design/telemetry/posterior.json to posterior.json.bak, then clears it to a fresh empty envelope. Mutation companion to read-only bandit-status. Use when the posterior is corrupted/unparseable, after a major agent/skill roster change invalidates accumulated arms, or when you deliberately want to rebootstrap adaptive routing from informed priors.
argument-hint	[--yes to skip the confirmation prompt]
tools	Read, Write, Bash, AskUserQuestion
disable-model-invocation	true

gdd-bandit-reset

Role

You are a deterministic, destructive maintenance skill. You are the ONLY skill that clears the bandit posterior - the mutation companion to read-only /gdd:bandit-status. You read the posterior path declared by scripts/lib/bandit-router.cjs's DEFAULT_POSTERIOR_PATH (.design/telemetry/posterior.json), REQUIRE explicit confirmation, back the file up to posterior.json.bak, then overwrite it with a fresh empty envelope so the next bandit pull rebootstraps from informed priors. See ./reference/bandit-integration.md for setup, interpretation, and convergence guidance.

Invocation Contract

• Input: optional --yes to skip the interactive confirmation (for non-interactive/automated runs).
• Output: a Markdown reset receipt to stdout (backup path + arms cleared + envelope written).

Procedure

1. Locate the posterior file

Read .design/telemetry/posterior.json (path declared by scripts/lib/bandit-router.cjs's DEFAULT_POSTERIOR_PATH - never hardcode a different path). Missing → nothing to reset; emit and skip to Section 5 (Record):

## Bandit Posterior Reset

No posterior file found at `.design/telemetry/posterior.json` — nothing to reset.

The next bandit pull with `adaptive_mode: full` will bootstrap a fresh posterior from informed priors. See `reference/bandit-integration.md`.

Note: the posterior only learns (updates from outcomes) on the SDK / headless session-runner path. In interactive Claude Code with adaptive_mode: full, the bandit samples from the configured priors but does not currently update them in-session. A reset therefore re-bootstraps the priors the SDK path will subsequently learn from. See reference/bandit-integration.md ("Where adaptive routing actually learns").

If present, count the arms (arms.length, treating a missing/non-array arms as 0) so the confirmation and receipt can report what will be cleared. A corrupted/unparseable file is still resettable - report arms: unknown (file unparseable) and continue.

2. Require explicit confirmation

This is a DESTRUCTIVE operation. Do NOT proceed without confirmation.

• If --yes was passed, skip straight to Section 3.
• Otherwise, prompt via AskUserQuestion: "Reset the bandit posterior at .design/telemetry/posterior.json? This clears learned arms. A backup will be written to posterior.json.bak first." with options Reset and Cancel.
• On Cancel (or any non-affirmative answer), abort WITHOUT touching either the posterior or the backup, and emit:

## Bandit Posterior Reset — Cancelled

No changes made. The posterior at `.design/telemetry/posterior.json` is untouched (<N> arms).

Then skip to Section 5 (Record) with reset: false.

3. Back up the current posterior

Copy the live posterior to .design/telemetry/posterior.json.bak (sibling backup) BEFORE clearing it, so the previous state is always recoverable. Overwrite any existing .bak from a prior reset. If the backup write fails, ABORT before clearing; never clear without a successful backup.

4. Clear to a fresh empty envelope

Overwrite .design/telemetry/posterior.json with a fresh empty envelope matching scripts/lib/bandit-router.cjs's loadPosterior() shape (SCHEMA_VERSION = 1.0.0, current ISO generated_at, empty arms):

{
  "schema_version": "1.0.0",
  "generated_at": "<ISO>",
  "arms": []
}

Write atomically where possible (.tmp + rename, mirroring savePosterior()). Then emit the receipt:

## Bandit Posterior Reset

Posterior cleared. The next bandit pull with `adaptive_mode: full` will rebootstrap from informed priors.

- Backup: `.design/telemetry/posterior.json.bak`
- Arms cleared: <N>
- Fresh envelope: `.design/telemetry/posterior.json` (schema_version 1.0.0, 0 arms)

Restore the previous state with: `cp .design/telemetry/posterior.json.bak .design/telemetry/posterior.json`
Verify the cleared state with `/gdd:bandit-status`. See `reference/bandit-integration.md`.

5. Record

Append one JSONL line to .design/skill-records.jsonl: {"skill":"gdd-bandit-reset","ts":"<ISO>","reset":<bool>,"arms_cleared":<count>,"backup_written":<bool>}. The skill mutates ONLY the posterior (+ its .bak) and appends to skill-records.jsonl (telemetry); it touches no other state.

Cross-references

• /gdd:bandit-status - read-only companion; inspect the posterior before/after a reset.
• ./reference/bandit-integration.md - operator guide; interpretation patterns and when a reset is warranted.
• scripts/lib/bandit-router.cjs - posterior shape, DEFAULT_POSTERIOR_PATH, SCHEMA_VERSION, loadPosterior(), savePosterior(), reset().