Langtalk

/langtalk — Hybrid Langtalks + Web research consultant

Combines two sources for every LLM-engineering question:

1. Langtalks — single-channel persistent NotebookLM notebook seeded with every public episode of the Langtalks podcast (channel @langtalks, id UCWPBxQSxychk2M49Fuoq-5A). Provides Israeli-practitioner production stories, named guests, Hebrew quotes, lessons-learned.
2. Web — current technical sources (papers, blogs, vendor docs, benchmarks). Provides recency, breadth, quantitative depth.

The skill returns a single synthesized answer in which every claim is tagged inline with its origin ([LT*] for Langtalks, [W*] for web), plus a unified sources footer.

Architecture (one notebook, forever)

• One persistent NLM notebook per install, identified by state.json → notebook.nb_id.
• Channel id pinned in config.json. No ad-hoc discovery.
• bootstrap seeds the notebook from the channel's upload history (cap 200).
• update adds new uploads since last_refresh. Old sources never removed.
• Queries auto-refresh if now - last_refresh > freshness_days (default 7).

Subcommands

How Claude should invoke this skill (hybrid default)

When $ARGUMENTS is a free-form question (not a subcommand), Claude MUST execute the hybrid flow:

Step 1 — Run langtalks AND web search in parallel

In a single message, fire both tool calls in parallel:

Tool 1 — Bash to invoke the langtalks layer:

# Plugin install: ${CLAUDE_PLUGIN_ROOT} is set by Claude Code.
# Standalone install: fall back to ~/.claude/skills/langtalk.
SKILL_DIR="${CLAUDE_PLUGIN_ROOT:+$CLAUDE_PLUGIN_ROOT/skills/consult}"
SKILL_DIR="${SKILL_DIR:-$HOME/.claude/skills/langtalk}"
cd "$SKILL_DIR"
ENV_FILE="${CLAUDE_PLUGIN_DATA:-$SKILL_DIR}/.env"
[[ -f "$ENV_FILE" ]] && { set -a; source "$ENV_FILE"; set +a; }
bash ./router.sh "$ARGUMENTS"

This returns: an answer body with [n] citations + a compact _Sources: ..._ italic footer with 1-2 episode URLs.

Tool 2 — WebSearch for the same question: Search the web for 4-7 high-quality sources (papers, vendor docs, technical blogs) published in the last 18 months. Capture title, URL, and published_at where available.

Step 2 — Synthesize a unified answer

Combine both into ONE flowing answer of 400-800 words. Every substantive claim must be tagged inline with its origin:

• [LT1], [LT2], ... — claims from Langtalks (renumber from langtalks's [n] to the unified scheme)
• [W1], [W2], ... — claims from web sources

Synthesis rules:

• Lead with whichever source has the strongest material for that paragraph. Don't artificially split or alternate.
• When both sources agree, tag both: ... cross-encoders generally outperform bi-encoders for the final reranking pass [LT1, W2].
• When they disagree or one is silent, tag the source that's making the claim. Do NOT fabricate web support for a langtalks claim or vice versa.
• Preserve direct Hebrew quotes from langtalks when they add color (with English glosses), but keep them tight — don't dump entire transcripts.
• If langtalks returned an empty answer or NLM timed out, fall back to web-only and note (langtalks layer unavailable: <reason>) in the footer.
• If WebSearch returns nothing useful, fall back to langtalks-only and say so.

Step 3 — Print a unified sources footer

After the answer, print:

--- WHERE THIS CAME FROM ---
LangTalks (<n> episodes cited):
  [LT1] "<episode title>" — <YouTube URL>
  [LT2] ...

Web (<n> sources):
  [W1] <title> — <publisher/year> — <URL>
  [W2] ...

LangTalks notebook last refreshed: <iso>

Keep the footer compact. List only sources that were actually tagged in the answer (not every source consulted).

Step 4 — One-line "what came from where" summary

End with a single italic sentence summarizing the split, e.g.:

Web supplied the technical primitives, model names, and 2025-2026 benchmarks; LangTalks supplied the production trade-offs and Israeli-practitioner workflows.

This is the user's quick orientation: at a glance, they see which source pulled the load.

Subcommand variants

• /langtalk skill-only "<q>" — run only router.sh "<q>", pass the langtalks output through verbatim. No WebSearch.
• /langtalk web-only "<q>" — run only WebSearch. No langtalks. Useful when the user knows the topic isn't podcast-relevant.
• /langtalk update / status / bootstrap — passthrough to router.sh <subcmd>. No web layer involved.

When to use the default (hybrid) mode

• Planning an LLM/agent system — wants production-grade trade-off advice.
• Trade-off questions ("X vs Y") — wants both textbook and practitioner views.
• Lessons-learned questions — wants both general industry consensus and specific practitioner stories.

When NOT to use

• Pure factual lookups (just use WebSearch directly — overkill to fire the podcast layer).
• Code-completion, debugging, command-syntax questions.
• Topics outside LLM/AI engineering.

Files

• config.json — channel id, freshness policy, caps.
• state.json — { notebook: { nb_id, video_ids, videos_meta, last_refresh, ... } }.
• .env — YOUTUBE_API_KEY=… (gitignored; never echo).
• scripts/common.sh — shared helpers (env, nlm auth, YT API, atomic state).
• scripts/bootstrap.sh — first-run seeding (now also caches videos_meta: title + url + published_at per video).
• scripts/update.sh — incremental refresh.
• scripts/query.sh — langtalks-only answer with [n] citations + compact sources footer.
• scripts/list.sh — status output.
• router.sh — entry point. Dispatches subcommands; for free-form questions returns langtalks-only output (the bash layer cannot synthesize with web — the LLM does that per Step 2 above).

Important: synthesis happens in Claude Code, not in bash

The bash skill provides ONE half (langtalks) as a primitive. Web search is a Claude Code tool (WebSearch). The hybrid synthesis is performed by Claude Code reading both tool outputs and weaving them. Do not try to call WebSearch from inside query.sh — it's an LLM tool, not a CLI.