Resume Handoff

---
name: resume-handoff
description:
  "Resume work from a handoff document. **ALWAYS use when** the user says 'resume handoff', 'pick up where we left off', 'continue from handoff', or provides a handoff document path. Verifies current codebase state against handoff, validates changes, and creates an action plan."
disable-model-invocation: false
allowed-tools: Read, Bash, TodoWrite
version: 1.0.0
---

# Resume work from a handoff document

You are resuming work from a handoff document through an interactive process. Handoffs carry context, learnings, and next steps from a prior session that need to be understood and continued — never assume the handoff's state still matches the codebase; verify first.

## Load on demand

| when | read |
| -- | -- |
| finding the handoff to resume from (no path given, path given, ticket given, or the cited path is missing on disk) | [`references/discovery.md`](references/discovery.md) |
| reading the handoff, verifying it against current state, and building the plan | [`references/process.md`](references/process.md) |
| deciding what to do given the codebase's divergence from the handoff | [`references/scenarios.md`](references/scenarios.md) |

## Prerequisites

```bash
# Thoughts must exist for this skill's documents. CTL-2306: the full host setup check (daemon,
# registry, house rules) belongs to the setup-catalyst skill, not to a skill that must run anywhere.
[[ -e thoughts/shared ]] || echo "⚠️ thoughts/shared is missing in $(pwd) — run \`humanlayer thoughts init\` or the setup-catalyst skill; if the prompt names an output path, write there" >&2

# CTL-2306 explicit-input discovery: begin
# Find the handoff to resume on disk for the ticket this run was given: $CATALYST_TICKET under a
# phase, else a ticket named in the skill's argument text (Claude Code substitutes the token in
# the heredoc below; another harness leaves it literal, which names no ticket). Nothing is
# remembered between runs. `[!0-9]` keeps PROJ-1 from matching PROJ-10's documents.
TICKET_ID="${TICKET_ID:-${CATALYST_TICKET:-}}"
if [[ -z "$TICKET_ID" ]]; then
  SKILL_ARGS=$(cat <<'CATALYST_SKILL_ARGS'
$ARGUMENTS
CATALYST_SKILL_ARGS
)
  TICKET_ID=$(printf '%s' "$SKILL_ARGS" | grep -oE '[A-Z]+-[0-9]+' | head -1)
  [[ -n "$TICKET_ID" ]] || TICKET_ID=$(printf '%s' "$SKILL_ARGS" | tr '[:lower:]' '[:upper:]' | grep -oE '[A-Z]+-[0-9]+' | head -1)
fi
RECENT_HANDOFF=""
if [[ -n "$TICKET_ID" ]]; then
  RECENT_HANDOFF=$(find -H thoughts/shared/handoffs -type f -name '*.md' -ipath "*${TICKET_ID}[!0-9]*" -exec ls -t {} + 2>/dev/null | head -1)
elif [[ -z "${CATALYST_PHASE:-}" ]]; then
  RECENT_HANDOFF=$(find -H thoughts/shared/handoffs -type f -name '*.md' -exec ls -t {} + 2>/dev/null | head -1)
fi
# CTL-2306 explicit-input discovery: end
# CTL-2104: guard the discovered path anyway — thoughts/shared is a per-project symlink and a path can vanish mid-run; an unguarded read of a phantom path yields an empty document that reads like an empty handoff.
if [[ -n "$RECENT_HANDOFF" && ! -f "$RECENT_HANDOFF" ]]; then
  echo "⚠️ Cited handoff is not on disk: $RECENT_HANDOFF"
  echo "   The channel is authoritative — recover from the last turn's text, see references/discovery.md."
  RECENT_HANDOFF=""
elif [[ -n "$RECENT_HANDOFF" ]]; then
  echo "📋 Found handoff: $RECENT_HANDOFF"
else
  echo "⚠️ No handoff found on disk for ${TICKET_ID:-this run}"
fi
```

## Configuration note

This skill uses ticket references like `PROJ-123`. Replace `PROJ` with your Linear team's ticket prefix — read it from `.catalyst/config.json` if available, otherwise use a generic `TICKET-XXX` form (`ENG-123`, `FEAT-456`).

## Invariants

- **Read the handoff document completely** — no `limit`/`offset` — and read every research or plan document it references, before proposing anything.
- **Never use sub-agents to read the handoff itself.** Sub-agents are fine for verifying the codebase state it describes ([`references/process.md`](references/process.md)).
- **Get user confirmation** before acting on the analysis, and again before starting implementation.
- **A missing handoff file is not lost work.** The channel/ticket thread is authoritative; recover from there rather than re-doing landed work ([`references/discovery.md`](references/discovery.md)).

## CLI tools

To fetch ticket context from Linear (e.g. a ticket referenced in the handoff), use the Linearis CLI — run `linearis issues usage` or see `/catalyst-dev:linearis` for exact syntax. Do not guess commands.