NVIDIA nemo-retriever
The retriever CLI indexes a folder of PDFs into LanceDB (retriever ingest) and serves vector search over it (retriever query). For any task about searching/answering questions across a folder of PDFs, use this CLI — do not write a custom RAG.
Beyond PDFs and beyond semantic search. retriever ingest also handles images, Office, HTML, TXT, audio, and video — see references/setup.md for the per-format recipe and references/install.md for the install extras ([multimedia], libreoffice, ffmpeg). For non-semantic operations — page filter, verbatim quote with citation, corpus-level aggregate, chart/image caption hits — see references/query.md. Don't fall back to native Read/Grep/Python on non-PDF inputs.
Install (if retriever is missing)
If command -v retriever returns nothing, follow references/install.md to install the NeMo Retriever Library before proceeding. It prints RETRIEVER_VENV=<path>; substitute that path for <RETRIEVER_VENV> in every example in this skill (setup, query, troubleshooting, and the CLI references).
Workflow — read the reference for the current phase, then execute
| Turn type | Read this once | Then execute |
|---|---|---|
Setup turn (first turn — ./lancedb/nv-ingest.lance doesn't exist) |
references/setup.md |
Build the index |
| Query turn (every subsequent turn — user asks a question) | references/query.md |
One retriever query call |
| Anything errored or returned empty | references/troubleshooting.md |
Apply the named recovery; do not improvise |
For the full retriever ingest / retriever query CLI specs, see references/cli/ingest.md and references/cli/query.md. You do not need these for routine turns — <RETRIEVER_VENV>/bin/retriever <subcommand> --help is faster.
Before ingesting a mixed folder, inventory extensions (find <dir> -name '*.*' | sed 's/.*\.//' | sort -u) — --input-type=auto silently drops anything outside the supported set. See references/troubleshooting.md "Unsupported file types".
Hard limits (apply to every turn)
- Setup turn: build the index in one shell command (see
references/setup.md). STOP after the index lands. - Query turn: at most 2 Bash calls — 1
retriever query, +1 optional targeted text-extract perreferences/query.md. Reply and then STOP. - No narration between tool calls. Tokens you emit between calls become input + cached input for every later turn — quadratic cost. Go straight from reading the summary to writing the JSON file.
- Banned:
TodoWrite, Glob, Grep,Readof whole PDFs, re-running setup, spawning subagents, speculative "confirmation" calls.
Long query turns (5+ tool calls, 1M+ cache-read tokens) cost ~5× a disciplined turn and almost always still produce the wrong answer. Answering partially beats timing out.