---
name: office-transform
description: Derive new Office files from structural selections without touching the original. Use when the user points at part of a spreadsheet, Word document, PDF, or PowerPoint deck (a worksheet range, paragraph, page, slide, shape, or a pasted selection-ref block) and wants it extracted, converted, or edited — the result is always a NEW file; the source file is never modified. Covers xlsx range extraction to csv/markdown/xlsx, docx paragraph extraction and text replacement, pdf page extraction, pptx slide/shape/table-cell extraction and editing, and targeted xlsx cell edits.
version: 1.0.0
---

# Office Transform

Turn a structural selection of an Office/PDF document into a new derived file.

Two invariants hold for every operation:

1. **The source file is read-only.** Every result is a new file; both scripts refuse to
   write to the source path or overwrite an existing file. Never work around this with
   ad-hoc shell edits to the original.
2. **Anchors are structural.** Selections address the document's own coordinates —
   worksheet + A1 range, body-level paragraph ordinal, one-based page number — never
   screen or DOM positions.

## When to use which tool

- Only need to *read* a document to summarize or answer questions → use
  `mcp__cherry-tools__to_markdown` instead (see the cherry-tool-guide skill); it is
  lossy but built for reading.
- The user wants a *file* out — an extracted range, a converted fragment, an edited
  copy → this skill.

## Input: selection references

Chat surfaces may hand you a fenced `selection-ref` block:

```selection-ref
{"path": "/abs/report.xlsx", "anchor": {"format": "xlsx", "sheet": "Sheet1", "range": "A1:C10"}, "excerpt": "…", "fileStamp": {"size": 1024, "mtimeMs": 1700000000000}}
```

The `anchor` object is exactly what the scripts take via `--anchor`.

**Freshness check.** `fileStamp.mtimeMs` is milliseconds since the Unix epoch, floored to
whole milliseconds. Do not compare it to `stat`'s default output: `stat -f %m` (macOS) and
`stat -c %Y` (GNU) give whole *seconds*, so multiplying by 1000 loses the sub-second part and
never matches. Read whole milliseconds the way the app wrote them:

```bash
uv run python -c "import os,sys;st=os.stat(sys.argv[1]);print(st.st_size, st.st_mtime_ns//1_000_000)" '/abs/report.xlsx'
```

Treat the file as changed when the size differs, or when the mtimes differ by more than 2 ms.
The tolerance is small on purpose: both sides floor the same nanosecond timestamp to
milliseconds, so they agree exactly, and the couple of milliseconds only covers the rounding
of a `double` that can no longer represent current epoch milliseconds exactly. A wider window
would hide real edits — a same-size change made within it would read as unchanged, which is
why the anchor check below is not optional. On a change, tell the user the file changed since
they selected and ask them to re-select — never silently re-anchor.

**Anchor check.** Before a patch-copy edit, also verify the anchor still points where the
user thinks: extract the anchored region and compare its text with the reference's `excerpt`,
normalizing both sides the same way (NFC, collapse each whitespace run to one space, trim).
The two are not equal and are not meant to be — the `excerpt` is what the user selected, while
the extract is the whole region an edit would replace. A selection sitting inside one region
makes the `excerpt` the shorter side; a selection running past that region anchors to where it
*starts*, which makes it the longer one. So the test is containment, whichever way round fits:
the `excerpt` appears inside the extract, or the extract's tail is where the `excerpt` begins.
Only when neither holds has the anchor stopped pointing at the selection — then stop and tell
the user, never edit at a mismatched anchor and never go searching for a "close enough"
location. Two cases need care because the two sides are not directly comparable as-is:

- **xlsx**: the `excerpt` is tab-separated cells and newline-separated rows, while extraction
  writes csv or md. Compare cell values, not the raw file — read the csv with a csv reader and
  join the fields with single spaces before normalizing, so `,` and `|` never count as a
  difference. That join drops the cell boundaries on both sides, so a match proves the text is
  unchanged, not the grid — the same words re-split across cells still reads as a match. The
  freshness check above is what catches that; never skip it on a passing anchor check.
  Number formats are the second asymmetry: the `excerpt` holds what Excel *displays*, because
  that is what the user pointed at (`1,234.50`, `45.67%`), while extraction writes the stored
  value (`1234.5`, `0.4567`). Neither side is wrong, so a formatted cell never matches
  literally. Compare those cells by value, and leave them out of the joined strings so the
  containment test runs on the text cells alone. Dates, times and durations are the same
  asymmetry seen from the other side: extraction writes one fixed shape (`2024-01-03`,
  `2024-01-03 15:04:05`, `26:30:00`) rather than the cell's format, so treat a cell that differs
  only in date or time presentation as a format difference too. A difference that is only the
  number format is not a moved anchor, and stopping on one sends the user back to re-select a
  selection that never moved.
- **docx with `charRange`**: the slice is only part of what patch-copy compares and replaces —
  it rewrites the **whole paragraph**. Extract the paragraph *without* `charRange` as well, and
  read "Edit docx" below before writing.

Users may also describe the region in words ("sheet 2, columns A through C"); build the anchor
JSON yourself, confirming the worksheet name or paragraph if ambiguous.

Anchor shapes:

| Format | Anchor |
| --- | --- |
| xlsx | `{"format":"xlsx","sheet":"Sheet1","range":"A1:C10"}` (range may be one cell) |
| docx | `{"format":"docx","paragraph":3,"paraId":"502E8D33","charRange":[0,12]}` (`paraId` optional = the paragraph's `w14:paraId`, resolved first when present; `charRange` optional; ordinal counts body-level paragraphs only, tables excluded) |
| pdf | `{"format":"pdf","page":3,"charRange":[0,120]}` (`charRange` optional, applies to extracted text) |
| pptx | `{"format":"pptx","slide":2,"nodeId":"4","paragraph":0}` or `{"format":"pptx","slide":2,"nodeId":"7","tableCell":{"row":1,"col":0}}` (`slide` is one-based; `nodeId` is the OOXML shape id — omit for the whole slide; `paragraph` and `tableCell` are optional, mutually exclusive, and only valid together with `nodeId`) |

## Operations

Scripts live in this skill's `scripts/` directory; resolve paths relative to this
skill folder. The library-edit recipes routed to below live in `references/` beside them.
Python dependencies are per-format and provided at invocation time via
`uv run --with <pkg>` (the bundled-shell idiom — do not `pip install` globally).

Which route an edit takes follows from the library that can write the format: `openpyxl`
drops charts and drawings on a round-trip, which is why xlsx edits go through patch-copy,
while `python-pptx` keeps XML it does not understand, which is why pptx edits go through
the library.

### Extract — pull the anchored region into a new file

Always single-quote paths — real documents have spaces in their names (`Q1 report.xlsx`).
If a path itself contains a single quote, close and reopen the quoting around it:
`'/abs/Bob'\''s deck.pptx'`.

```bash
uv run --with openpyxl python scripts/office_extract.py \
  --file '/abs/report.xlsx' \
  --anchor '{"format":"xlsx","sheet":"Sheet1","range":"A1:C10"}' \
  --out '/abs/report-q1-range.csv'
```

The output format is inferred from `--out`'s extension:

| Source | Dependency (`--with`) | Output formats |
| --- | --- | --- |
| xlsx | `openpyxl` | `xlsx`, `csv`, `md` |
| docx | `'python-docx>=1.1,<2'` | `docx`, `txt`, `md` |
| pdf | `pypdf` | `pdf` (page copy), `txt`, `md` |
| pptx | `python-pptx` | `txt`, `md` (slide, shape, paragraph, or table-cell text) |

The docx pin is not optional. Patch-copy's `expectText` gate compares a paragraph read
with python-docx against the same paragraph read by the script's own `paragraph_text`,
which reproduces python-docx's `Paragraph.text` element for element. That equivalence was
checked against 1.x; a release that changes what `.text` spells would make the gate refuse
paragraphs nobody edited. Quote the specifier — `>` and `<` are redirects to a shell.

xlsx extraction reads computed values (`data_only`), so formula cells yield their last
saved result. docx extraction to `docx` carries text only, not run styling.

### Patch-copy — derive an edited copy, standard library only

```bash
uv run python scripts/office_patch_copy.py \
  --file '/abs/report.xlsx' \
  --edits '{"format":"xlsx","sheet":"Sheet1","cells":{"B2":42,"C3":"hello"}}' \
  --out '/abs/report-updated.xlsx'
```

OOXML packages are ZIPs of XML parts. Patch-copy copies every part byte-for-byte and
re-serializes only what an edit reaches — the target worksheet or `word/document.xml`, plus
the workbook bookkeeping noted below for xlsx — so styles, charts, images, and macros in
untouched parts survive exactly. Edit shapes:

- `{"format":"xlsx","sheet":"S","cells":{"B2":42,"C3":"text","D4":true}}` — numbers,
  strings, and booleans; an existing formula in an edited cell is replaced by the value.
  Patch-copy does not recalculate, so a formula reading an edited cell keeps the value it
  last cached; every write sets `fullCalcOnLoad` in `xl/workbook.xml` so Excel recomputes
  those on open.
  Replacing a formula also drops `xl/calcChain.xml` (a recalculation cache Excel rebuilds),
  along with the content-type and relationship entries that would otherwise point at a part
  no longer there; keeping a chain entry for a cell that no longer has a formula makes Excel
  report the derived file as damaged. Cells in a **shared, array, or data-table formula group are refused** — the
  expression lives in one member and the others only reference it, so overwriting a member
  would strip the formula from cells you never named. Rewrite such a range with `openpyxl`.
  Coordinates outside the worksheet grid (past XFD or row 1048576) are refused too.
- `{"format":"docx","replacements":[{"paragraph":3,"text":"new text","paraId":"502E8D33","expectText":"old text"}]}` —
  the paragraph keeps its paragraph style and the first run's character style; extra run-level
  styling within that one paragraph is flattened into the new text.
  **`text` must be the complete new paragraph.** The whole body paragraph is replaced, and
  `charRange` does not narrow that — feeding back a `charRange` slice as `text` silently
  discards the rest of the sentence.
  The output is exactly `w:p > [w:pPr] + w:r > [w:rPr] + w:t`, so a paragraph holding anything
  that shape cannot carry is **refused**, not silently stripped. That covers bookmarks, comment
  anchors and fields (their start/end can pair across paragraphs, and rewriting one half
  unbalances the document), images, embedded objects, footnote/endnote references, hyperlinks,
  tracked changes and moves, content controls, equations — and anything else not on the short
  allow-list, including elements from namespaces that did not exist when this was written.
  A dropped `w:del` would even accept a pending deletion on the user's behalf.
  A page or column break (`<w:br w:type="page"/>`) is refused for a quieter reason: it carries no
  characters, so the extract reads the text on either side of it as one string and the anchor check
  cannot see that the rewrite would delete it. A bare `<w:br/>` line break still passes.
  To edit such a paragraph, see **"Edit docx"** below — do not reach for
  `Paragraph.text`, which destroys exactly the same content, only silently.
  `paraId` (optional) is resolved before the ordinal; a disagreement between the two is an
  error, never a silent pick. `expectText` (optional but strongly recommended) is a hard
  gate: the target paragraph's current text must match it after whitespace normalization or
  the edit is refused. **Take its value from an extract of the same paragraph taken without
  `charRange`** — the gate compares the whole paragraph, and a selection-ref `excerpt` is
  truncated at 2000 chars and may span more than the edit target.
- Any text written into a cell or paragraph must be storable in XML: control characters
  other than tab, newline and carriage return are refused. Text extracted from a deck can
  carry them (python-pptx maps a soft line break to `\x0B`), so strip them before feeding
  extracted text back in as an edit value. A **docx paragraph** refuses tab, newline and
  carriage return as well: WordprocessingML spells those `<w:tab/>` and `<w:br/>`, and the
  single `w:t` this rewrite emits cannot carry them. Extracting a paragraph that holds them
  gives you `\t` / `\n`, so editing that string and writing it back would delete the
  elements while reading identically — split the content across separate body paragraphs,
  or see **"Edit docx"** below.

Text comparisons on both sides of this skill use one normalization rule, identical
to the renderer's `normalizeSelectionText`: NFC-normalize, collapse every whitespace
run to a single space, trim the ends.

### Generate — write ad-hoc library code for new documents

Generation (a fresh deck, workbook, or document — from scratch or from data you
just extracted) has no source file to protect, so there is no fixed script: write a
short Python program against the matching library (`python-pptx`, `openpyxl`,
`python-docx`) and run it via `uv run --with <pkg> python`. The two skill
invariants still apply: write to a path nothing occupies yet — open it with `"xb"`
rather than handing the library a name, since every one of these `save()` methods
overwrites — and verify the output by reopening it before reporting success.

### Edit docx — edit runs, never `Paragraph.text`

When patch-copy refuses a paragraph, `python-docx` can still edit it — but only run by run.
Never assign `paragraph.text = "..."`: it inflicts exactly the loss patch-copy refused, minus
the refusal. `save(path)` overwrites, so open the destination with `"xb"`.

Read [references/docx-edit.md](references/docx-edit.md) before writing any python-docx edit.

### Edit pptx — use python-pptx, saving to a new path

pptx edits do not go through `office_patch_copy.py`. Never assign `.text` at paragraph or
shape level: it rebuilds that subtree as one unformatted run. Edit runs, and open the
destination with `"xb"`.

Read [references/pptx-edit.md](references/pptx-edit.md) before writing any python-pptx edit.

## Output conventions

- Name derived files after the source with an operation suffix:
  `report.xlsx` → `report-updated.xlsx`, `report-q1-range.csv`, `spec-p3.txt`.
- Write into the session workspace (or where the user asked). Both scripts print the
  written path on success — report it to the user.
- `--file` and `--out` must both be absolute; a relative path is refused rather than
  resolved against whatever working directory the shell happens to be in.
- Output is staged and renamed on success, so a failed run leaves nothing behind and the
  same command can be retried at the same path.

## Verify before reporting success

Always reopen the derived file with the matching reader and check the result, e.g.:

```bash
uv run --with openpyxl python -c "
from openpyxl import load_workbook
ws = load_workbook('/abs/report-updated.xlsx', data_only=True)['Sheet1']
print(ws['B2'].value)"
```

`data_only` reads cached values and patch-copy does not recalculate, so a formula reading a
cell you just wrote still reads back its old result. Check the cells you wrote, and tell the
user the dependent totals are recomputed when Excel opens the file.

A written xlsx string cell that held a literal `_xHHHH_` or a carriage return reads back through
openpyxl in its escaped form (`_x005F_xHHHH_`, `_x000D_`) — see the ST_Xstring note under
"Limits". That is the reader, not a verification failure.

If verification fails, say so and show the error — do not present an unverified file.

## Limits

- pptx edits go through python-pptx (see "Edit pptx"), not patch-copy; slide-copy
  into a new deck is not supported (python-pptx cannot clone slides) — say so
  when asked for it.
- Patched xlsx string cells become inline strings (valid OOXML; Excel reads them fine). Their
  text is written as ST_Xstring, so a literal `_xHHHH_` in the value is escaped to
  `_x005F_xHHHH_` and a carriage return is stored as `_x000D_` — that is what makes Excel show
  the characters that were written. openpyxl decodes neither, so a verification read of such a
  cell shows the escaped form; that is the reader, not the file.
- Edited XML parts may lose insignificant serialization details (attribute quoting,
  empty-element form); namespace prefixes and untouched content are preserved.
- A patched docx paragraph keeps its characters but not every break opportunity: `w:softHyphen`
  leaves no mark in the extract and is dropped, and `w:noBreakHyphen` comes back as a plain `-`, so
  what both lose is only where a line may break. `w:sym` is refused instead — its glyph is a
  character the reader can see, not a hyphenation hint.
- xlsx extraction refuses ranges over 1,000,000 cells; both scripts refuse packages
  with more than 10,000 entries, an entry over 256 MiB uncompressed, or over 1 GiB
  total uncompressed — ask the user for a smaller selection or file instead of
  retrying.
- xlsx extraction does not mask merge followers — the streaming reader cannot see the
  merge ranges. Excel and openpyxl clear the covered cells when a merge is made, so
  followers normally extract as empty, matching what the user sees; a file that kept hidden
  text under a merge (LibreOffice offers to) extracts that text as its own cell. If the
  anchor check fails inside a merged range, look at the cells before telling the user to
  re-select.
- csv and md carry cell text verbatim, formula-looking text included (`=SUM(A1)`, `+1`,
  `-`); a spreadsheet opening the csv would evaluate it, which matters only for a source
  the user does not trust — say so if they mean to open the csv in one. In the derived
  xlsx, text that openpyxl would re-type — a leading `=` into a live formula, an error code
  such as `#N/A` into an error value — is written back as quote-prefixed text; `+1` and `-`
  are already stored as text and stay that way, and a cell that really holds an error stays
  an error.
- Scanned/image-only PDFs yield no text (no OCR here).