Codex Office Skills: 12 Excel, Word, PowerPoint, and PDF Examples

These are four file Skills available in the Codex desktop setup used for this guide. They are not four defaults guaranteed in every ChatGPT account. In ChatGPT, open Plugins → Skills → Installed to see what you have; availability depends on the product and workspace. The file type and installed Skill name differ:

Get the files and start

Download the practice files ZIP and extract it. The first task in each chapter uses workshop_sessions.csv, workshop-memo.docx, workshop-deck.pptx, or workshop-memo.pdf. Open a Codex desktop task, attach that file, paste the prompt, then compare the result with the stated check. You can start with any chapter.

The prompts name a Skill, but that wording alone does not prove activation; check the Skill shown in your session. The @Documents, @Spreadsheets, and @Presentations template gallery in ChatGPT Work is a separate workflow from these Codex file examples. OpenAI says its desktop Work flow did not include PowerPoint at launch. Editing a workbook already open in Excel uses the separate ChatGPT for Excel add-in.

A small source file for the examples

The ZIP already contains workshop_sessions.csv. If you want to make it yourself, copy the text below into a file with that name. It describes six invented workshop sessions. Ticket sales precede refunds, the ticket price is $45, and the only listed costs are venue and materials. S04 was canceled with zero sales.

session_id,date,status,capacity,tickets_sold,refunds,ticket_price_usd,venue_cost_usd,materials_cost_usd
S01,2026-08-03,completed,30,24,2,45,300,150
S02,2026-08-10,completed,30,28,1,45,300,170
S03,2026-08-17,completed,30,18,0,45,300,130
S04,2026-08-24,canceled,30,0,0,45,0,0
S05,2026-09-07,completed,30,26,3,45,300,160
S06,2026-09-14,completed,30,21,1,45,300,145

The independently checked totals are 117 tickets sold, seven refunds, and 110 net tickets. Revenue is 110 × $45 = $4,950. Venue and materials add to $2,255, leaving $2,695 after those listed costs. Staff time and taxes are absent. The overall refund rate is 7 ÷ 117 = 5.9829%. Keep these answers nearby while trying the Skills.

Excel Skill (Spreadsheets)

Simple: ask a question about a CSV without making a workbook

Attach workshop_sessions.csv from the practice ZIP. Ask for both the result and the arithmetic so you can see whether the answer accounts for refunds.

Use the Spreadsheets Skill to read the attached CSV. Which session
had the highest net ticket revenue? Calculate revenue as
(tickets_sold - refunds) × ticket_price_usd. Also report the total
number of refunds and identify the canceled session. Do not edit
the CSV or create a workbook for this question.

Expected answer: S02 has (28 - 1) × $45 = $1,215, the highest session revenue. Refunds total seven; S04 is canceled. We checked those values directly from the six source rows. If a response reports S02 as $1,260, it multiplied 28 sold by $45 and forgot its refund. This is a useful first request for an unfamiliar spreadsheet: answer one question, inspect the cited rows, and only then ask for a new file.

Intermediate: create a formula-driven XLSX with a chart

Attach workshop_sessions.csv again. This time ask for an editable XLSX with a Summary sheet and a Sessions sheet. The ZIP includes workshop-model.xlsx as a comparison output.

Use the Spreadsheets Skill to create an editable XLSX from the
attached workshop_sessions.csv. Keep all six source rows on a
Sessions sheet. Add formula columns for net tickets, net ticket
revenue, venue plus materials costs, contribution after listed
costs, and refunds / tickets sold. Leave the session refund rate
blank when tickets_sold is zero. Put a Summary sheet first with
the overall totals and a native chart comparing revenue and
listed costs by session. Recalculate, render both sheets, and
reopen the exported XLSX before returning it.

The saved Summary sheet shows 117 sold, seven refunds, 110 net tickets, $4,950 revenue, $2,255 costs, and $2,695 contribution. Its refund rate displays as 6.0% with one decimal place; the underlying value is 0.05982905982905983. The chart includes S04 at zero, so it still represents all six rows. Open the image at full size to read the sheet labels.

Open Sessions as well. In row 2, net tickets use =E2-F2, revenue uses =J2*G2, listed costs use =H2+I2, and contribution uses =K2-L2. The copied refund formula is =IF(E2=0,"",F2/E2). Its row-5 result for canceled S04 is blank. A displayed 0% there would misstate an undefined rate.

Test a dependency before trusting the file: in a disposable copy, change Sessions!E2 from 24 to 25. Revenue on Summary!B8 must rise by one $45 ticket, from $4,950 to $4,995. Restore 24 and check that revenue returns to $4,950. Our local run did both, then reimported the exported XLSX and found the S04 formula and one native chart still present.

Advanced: add a price scenario without overwriting source data

Attach the XLSX you just made, or use workshop-model.xlsx from the ZIP. The output is a second workbook with one case selector; compare it with workshop-scenarios.xlsx. The six original $45 source prices remain in Sessions, while Assumptions controls the modeled price.

Use the Spreadsheets Skill to make a scenario copy of the attached
workbook. Preserve the Summary and Sessions sheets, source rows,
refund formulas, and native chart. Add an Assumptions sheet with
one selector: 1 = base price $45, 2 = scenario price $50. Link
the revenue formulas to the active price, but keep the original
ticket_price_usd source cells unchanged. Show the active case and
active price on Summary and Sessions. Test both cases, restore
the selector to 1, and reopen the exported XLSX.

In the tested copy, Assumptions!B2 is the selector and B6 calculates the active price with =IF(B2=1,B4,B5). Session revenue uses formulas such as =J2*Assumptions!$B$6. The source ticket price in Sessions!G2 stayed at $45. With selector 2, the active price was $50 and the control sheet looked like this:

At $50, 110 net tickets produce $5,500 revenue. The listed costs remain $2,255, so contribution becomes $3,245. Both the Summary values and chart changed. Restoring selector 1 returned revenue to $4,950; the saved and reopened workbook defaulted to that base case and retained one native chart. Check the active-case label whenever you copy a figure out of a scenario model, since $5,500 and $4,950 are valid answers to different assumptions.

Word Skill (Documents)

Simple: answer a question from an existing DOCX

Attach workshop-memo.docx from the practice ZIP. The task is to extract its proposed next step and the limitation on its $2,695 figure without editing the file.

Use the Documents Skill to read the attached DOCX. What is the
proposed next step? Quote the figures for revenue, listed costs,
and contribution, and name the costs that are missing from the
calculation. Tell me which heading contains the next step.
Do not edit or re-export the file.

The memo says to estimate staff and tax costs before calling the pilot profitable or planning another run. It lists $4,950 revenue, $2,255 venue and materials, and $2,695 contribution after those costs. The action appears under “Proposed next step.” We checked the paragraphs and eight-row table in the DOCX.

Intermediate: create a one-page memo and make one scoped edit

Attach workshop-model.xlsx from the ZIP, or the workbook you made in the Excel chapter. Create an editable decision memo with a compact table. The ZIP includes workshop-memo-before.docx and workshop-memo.docx for comparison.

Use the Documents Skill to create a one-page editable DOCX
decision memo for someone considering another workshop run.
Lead with the proposed next step. Include a table for tickets
sold, refunds, net tickets, net ticket revenue, listed costs,
contribution after listed costs, and refund rate. Use the
verified workbook figures and state that staff time and taxes
are absent. Add the synthetic source at the bottom. Render
and inspect the finished DOCX page.

The initial memo had one page and an eight-row table including its header. We then made a narrow change: replace the heading “Pilot result” with “Proposed decision.” Give an exact replacement when you want the rest of a Word file preserved:

In the attached DOCX, replace only the heading "Pilot result"
with "Proposed decision". Keep the table, figures, other headings,
source note, and page layout. Return an editable DOCX, reopen it,
and render the complete final page for comparison.

The reopened file contained the new heading, the same table size, and the $4,950 and $2,695 figures. It still rendered as one page. Compare it with the earlier image: the requested heading changed; the surrounding explanation and table remained. For your own document, scan the rendered page for broken table rows, clipped text, or unexpected style changes after every edit.

Advanced: send a review copy with a real tracked change and comment

Attach workshop-memo.docx, either from your intermediate result or the practice ZIP. Ask for a review copy with a tracked heading change and a comment anchored to the contribution statement. Compare the result with workshop-review.docx in the ZIP.

Use the Documents Skill to prepare a review copy of the attached
DOCX. Track a replacement of the heading "Proposed decision"
with "Decision for review". Add a Word comment to the $2,695
contribution paragraph: "Please estimate staff time and taxes
before treating this contribution as profit." Preserve the
table and all figures. Return the review DOCX, confirm that it
contains one tracked deletion, one insertion, and one comment,
then render it for a layout check.

The review copy stored one tracked deletion of “Proposed decision,” one tracked insertion of “Decision for review,” and one comment anchored to the $2,695 paragraph. We checked the DOCX review objects directly. The headless render joined the old and new heading text and did not reliably show the comment, so it cannot serve as a screenshot of Word's review interface. Open workshop-review.docx in a Word-compatible editor to inspect the markup; Microsoft Word's review pane was not tested here.

Once the reviewer approves, make a separate clean copy:

From the attached review DOCX, accept the tracked heading
change and remove its comment. Keep the original review copy.
Preserve the table, figures, and one-page layout. Return a
clean editable DOCX, reopen it, and render its complete page.

Our resulting workshop-review-approved.docx had “Decision for review,” no remaining tracked insertions or deletions, no comment part, the same eight-row table, and the verified figures. It rendered as one page. Keep the review copy for anyone who needs the change history.

PowerPoint Skill (Presentations)

Simple: inspect an existing deck before editing it

Attach workshop-deck.pptx from the practice ZIP. Find the relevant slide without generating another deck. The sample has four slides.

Use the Presentations Skill to inspect the attached PPTX.
How many slides are there? Which slide contains the chart?
What decision does the last slide ask for? Check whether
each slide has a source note. Do not edit the PPTX.

The inspected file had four slides, its chart was on slide 2, and slide 4 asked for staff and tax cost estimates before another run. All four slides had source notes. The first slide below labels $2,695 as “contribution after listed costs.”

Intermediate: build a four-slide meeting deck

Attach workshop-model.xlsx and workshop-memo.docx from the ZIP, or the files you created earlier. Ask for four slides with separate jobs. The ZIP includes workshop-deck.pptx as the comparison output.

Use the Presentations Skill to make an editable four-slide PPTX.
Slide 1: $2,695 contribution after listed costs.
Slide 2: revenue and listed costs for S01-S06 in a native chart;
         keep canceled S04 at zero in both series.
Slide 3: seven refunds / 117 sales = 5.98% rounded; explain why
         S04 has no individual refund rate.
Slide 4: estimate staff time and taxes before another run.
Use the verified workbook and memo. Put the fictional source in
speaker notes, render every slide, and report what remains untested.

Slide 3 displays both the numerator and denominator. Slide 4 pairs $4,950 revenue with $2,255 listed costs and the $2,695 difference, then names the costs still missing. We rendered all four slides from the final PPTX. Slide 2 contains a native chart with six sessions, including canceled S04 at zero:

The two decision slides look like this:

Advanced: redesign the deck for a five-minute live briefing

The intermediate deck reports the figures. The advanced job is to make the same evidence easy to follow from the back of a meeting room. Attach workshop-deck.pptx and workshop-memo.docx. The audience is a program manager and budget owner deciding whether to commission staff and tax cost estimates before another run. Keep every number and its qualification; change the sequence, emphasis, and amount of text on screen.

Use the Presentations Skill to redesign the attached deck for a
five-minute live briefing to a program manager and budget owner.
The decision is whether to estimate staff time and taxes before
planning another workshop run. Use the memo as the source.

Make a separate editable PPTX with one message per slide:
1. Open with $2,695 contribution after listed costs, and state
   that staff time and taxes are unknown. Do not call it profit.
2. Show the six-session revenue/cost comparison in one native,
   editable chart. Direct attention to canceled S04 at zero.
3. Show 5.98% with its denominator: 7 refunds / 117 sold.
4. Give the missing costs their own clear slide.
5. End with the requested next action, not another data table.

Use large type, strong contrast, generous space, and speaker
notes for supporting detail and source references. Keep $4,950
revenue, $2,255 listed costs, $2,695 contribution, and all chart
values unchanged. Render every slide and inspect for clipping,
readability, chart editability, and a clear five-minute flow.

Start by changing the opening slide. The basic version announces the project and puts the qualified $2,695 figure lower on the page. The live version makes that figure readable at a distance and keeps “after listed costs” beside it. The missing-cost caveat stays on the slide:

In the original chart, every session has equal visual weight and the canceled S04 is easy to overlook. The redesigned version keeps the same editable series, enlarges the session and legend labels, and explains S04 beside the chart. The values stay unchanged while the viewer's attention moves to the canceled session:

Give the limitation its own slide. The $2,695 figure excludes staff time and taxes, so the redesigned deck states that limitation in large type instead of leaving it as a small line beneath three monetary figures:

The basic closing slide lists revenue, costs, and contribution together. In the live version, those supporting figures move to the speaker notes. The audience sees a single request: estimate the missing costs before another run.

Our locally built reference output, workshop-deck-presented.pptx, has five slides: takeaway, evidence chart, refund context, missing costs, and decision. Play your deck in slide order. If a viewer cannot read the qualification next to $2,695, find S04 and the 7/117 denominator, or state the final requested action, ask for a focused revision and render again. We reopened the reference file, checked its native chart and embedded values, and inspected all five rendered slides. This checks file layout; it does not establish readability from the back of a real room or prove a five-minute delivery. We did not test it in Microsoft PowerPoint or run the copyable prompt as a separate blind one-shot task.

PDF Skill

Simple: read a PDF and extract exact values

Attach workshop-memo.pdf from the ZIP. This one-page PDF is a fixed-layout version of the Word memo. Ask for its decision and numbers without making a new file.

Use the PDF Skill to read the attached workshop-memo.pdf.
What is the proposed next step? Report net ticket revenue,
listed costs, and contribution after those costs. Name the
costs missing from the calculation and the heading that
contains the next step. State the page count. Do not edit
or re-export the PDF.

The answer should identify “Proposed next step” on page 1: estimate staff and tax costs before calling the pilot profitable or planning another run. The PDF contains $4,950 net ticket revenue, $2,255 listed costs, and $2,695 contribution after those costs. We extracted the PDF text and rendered its single page; the figures and missing-cost warning were present in both.

Intermediate: create and fill an interactive form

Create a blank one-page form, then fill a separate copy. The practice ZIP includes workshop-request-blank.pdf and workshop-request-filled.pdf for comparison. Ask for actual interactive fields rather than lines that only resemble a form.

Use the PDF Skill to create a one-page interactive request form.
Add labeled text fields named program, period, tickets_sold,
refunds, net_revenue, listed_costs, contribution, and next_step.
Leave them blank. Add a footer saying contribution excludes
staff time, taxes, and unlisted costs. Render the blank form
and check that all eight fields exist.

The blank form used in the test had eight stored fields and eight page widgets. Its labels and footer were visible in this render:

Next, attach your blank PDF and workshop-model.xlsx. Make the values explicit, and request a readback of both stored fields and the visible page:

Fill the attached PDF using the verified workshop figures.
Program: Workshop pilot. Period: Aug-Sep 2026.
Tickets sold: 117. Refunds: 7. Net revenue: $4,950.
Listed costs: $2,255. Contribution: $2,695.
Next step: Estimate staff and tax costs before another run.
Keep the output interactive. Reopen it, check every stored
field and page widget, then render the final page.

The filled PDF reopened with all eight field values, eight page widgets, and an appearance stream for each updated widget. The render showed every value without clipping. Checking only the image would have missed a possible mismatch between what a person sees and what another system reads from the form fields.

Advanced: catch a wrong field, repair it, then flatten a recipient copy

Attach workshop-request-needs-review.pdf and workshop-model.xlsx from the ZIP. This deliberately faulty form says the contribution after listed costs is $2,965. The workbook says $2,695. Your job is to compare the field values with the workbook, correct only the mismatch, retain an interactive audit copy, and then make a static recipient copy.

Use the PDF Skill to audit the attached request form against
the workbook Summary sheet. Read the PDF's stored field values
and visible page. List every mismatch with the workbook value.
Correct the form in a separate interactive PDF, preserving its
other seven fields. Reopen it and check every stored field,
widget value, and visible appearance. Then flatten a second,
static recipient PDF from the corrected copy. Keep the same
visible values, remove all form fields and widgets, reopen it,
and render both outputs. Return the mismatch list and both PDFs.

The faulty input makes the test observable: its contribution field displays $2,965:

Our corrected copy is workshop-request-corrected.pdf; its eight stored fields and eight widgets matched the workbook values. The static workshop-request-flat.pdf kept the corrected values on the page but reopened with zero fields and zero widgets:

A screenshot shows the visible correction, but only a field readback verifies that the interactive data changed and the recipient copy is flat. We checked both structures and rendered all three PDFs. We did not open them in Adobe Acrobat.