deskstack

Claude builds your DCFs and comps from SEC and European filings, and a second agent checks every number against the filing. In the benchmark, 0 of 3,230 reported figures were wrong with deskstack, against 36 of 1,018 (3.5%) with web search only.

If it saves you a tie-out, a star helps others find it.

Website · Examples · Tutorial · Tutoriel (FR)

Public beta. The hosted connector is online at https://deskstack.deskstack-server.workers.dev/mcp. Feedback and issues are welcome.

Why

With web search only, Claude fills gaps with numbers that aren't in the filing. In the benchmark (50 companies, a DCF and a comps table each):

• DCF: share counts derived from net income ÷ EPS, or taken from six months or one quarter; capex estimated as operating cash flow minus free cash flow; non-GAAP "adjusted revenue"; a segment's D&A used for the group's; figures from aggregator sites or Wikipedia. 20 wrong figures, in 12 of the 50 models. Claude flagged about half of them in its own notes, but the numbers went into the model.
• Comps: 15 of the 16 wrong figures were last-twelve-months figures a quarter late, from an aggregator that still showed the twelve months to June after the September 10-Qs were filed. 7 more were left as 0 placeholders.

deskstack gives Claude the filed figures, each with its filing, and reviewers that check every typed number. In examples/apple-dcf-typo, Apple's FY2025 revenue is typed as 416,116: /associate says the 10-K reports 416,161 and that two digits look swapped. /md-redteam shows what a price implies: at $230 a share, the Apple example model implies a WACC of 7.74%, against the 10.6% it uses.

Benchmark

How many reported figures in an AI-built model are wrong, with and without deskstack. 50 companies (35 US, 15 European), three setups, Claude Sonnet 5.5. Every figure the scorer called wrong was read by hand against the filing.

Cost and time are averages per model. "Wrong" means the figure differs from the filing for the period asked. Not every run finished: 49 of 50 DCFs with deskstack data, 45 of 50 comps tables with web search only. Analyses: DCF, comps.

Read the 0 with care. It is partly by construction: the deskstack setups read the same data the scorer checks against, so the 0 says the models copied deskstack's figures faithfully. Whether those figures are right is checked separately, by the golden set and a nightly re-read with other XBRL parsers (Accuracy). Each analysis also lists what the run found wrong in deskstack itself, and what was fixed. With 30 searches per request and high effort instead of 12 and medium, web search still wrote a wrong figure (1 of 117), and left none as 0 (robustness check). The runner, the frozen company set and the method are in bench/; the chart version is bench/benchmark.svg.

Set up in the Claude app

deskstack has two parts. The data connector gives Claude filed figures, each with its source; you add it once, by pasting a URL. The plugin adds the roles: commands you type in a chat, such as /analyst or /associate.

The connector works on any Claude account; a free account can add one custom connector. The plugin needs a paid plan, and code execution turned on in Settings → Capabilities. No terminal is needed.

1. Data: in Claude, open Customize → Connectors → Add custom connector and paste https://deskstack.deskstack-server.workers.dev/mcp, with no sign-in. Check it: ask "Using deskstack, what was Apple's revenue in FY2025? Cite the filing." The answer should be $416,161 million, citing an Apple 10-K and its accession number. You can also run your own copy (self-hosting).
2. Roles: open Customize → Plugins → Add marketplace, paste https://github.com/joaquimmj/deskstack, then install deskstack.
3. Try it: /deal-team Apple quick-dcf. If something fails, /deskstack-doctor checks the connector, the plugin version, Python and the bundled scripts, and says how to fix what doesn't work.

The tutorial walks through a first reviewed DCF in about 10 minutes: English · français. In Claude Code: /plugin install deskstack --marketplace joaquimmj/deskstack (2.1.275+).

What you get

A workbook with blue inputs, formulas, and a Sources sheet that cites the filing behind every typed number:

Review reports from each role, and one sign-off page. Nothing is exported until you approve it in your own words:

Both images are rendered from the files in examples/apple-dcf by docs/media/make_media.py. Open the workbook and every report there, or the four other examples, including a model with errors typed in on purpose.

Free plan: tie out without the plugin

The roles need a paid plan, but the connector's verify_value works on a free account. Paste this, with your own figures:

Using deskstack, check these figures against the filings with verify_value, then list each as match or
mismatch with the filed value, the filing, and the hint if there is one. Do not correct anything yourself.
Company: Apple (AAPL), figures in USD millions.
- Revenue FY2025: 416,116
- Operating income FY2025: 133,050
- Net income FY2024: 93,736

The first line is the typo from the demo: verify_value answers that the 10-K reports 416,161 and that two digits look swapped.

What it catches

Real errors from the benchmark, each read by hand against the filing.

To see these caught, open examples/errors-caught: a Microsoft DCF with four of these errors typed in on purpose, and the reports that find all four.

verify_value also names the usual causes of a mismatch: wrong scale, opposite sign, another period, another line item, another currency, two digits swapped, or another common definition (net debt with leases, equity without minorities). The 21 model rules are listed in checker/README.md.

Check any AI-built model in one command

For teams with a terminal or a repository; the Claude app doesn't need it.

deskstack-check checks any .xlsx model, whether Claude, ChatGPT, Copilot, another tool or a person built it.

• Offline: the 21 model checks (hardcodes, broken rows, balance sheet, terminal value, placeholders…).
• With --verify: every typed figure is also tied to the SEC or ESEF filing through the deskstack connector. Only those figures are sent, each with its line item, period and cell reference (e.g. Inputs!C5).

pipx run deskstack-check model.xlsx            # soon: the package isn't on PyPI yet
pipx run --spec ./checker deskstack-check model.xlsx   # today, from a clone

$ deskstack-check examples/apple-dcf-typo/model.xlsx --