Diligence Desk: the first plugin through the portal, and every rule it met.
Diligence Desk is a free tool from Black Matter that runs first-pass due diligence on US companies from public records: SEC EDGAR, GLEIF, USAspending, the domain registry and GitHub. It is published under Black Matter’s name, on its own domain, with its own product and policy pages. It was first uploaded to OpenAI’s plugin portal on 24 Oct 2026.
Black Matter VC also operates Plugferry. Diligence Desk was the first plugin built with it, migrated the way a customer would migrate a GPT.
- 14
- tools across 6 public-record APIs
- 1
- Action parked (SAM.gov)
- 18
- calls in 26 seconds for one ChatGPT answer
- 8
- review cases written into the ZIP
- 23 Oct · Import
One Action failed for every request.
SAM.gov answered 404 to everything with a valid key. Its terms also forbid sharing a personal key, and a personal key without a role gets 10 requests a day.
In Plugferry now: Each Action is called once after import, and “Works” and “Allowed” are shown as two separate facts. Failing Actions can be parked.
- 23 Oct · Bridge
The SEC and the US Treasury refuse Cloudflare’s network.
Both answered 403 or 525 from the edge and worked from elsewhere.
In Plugferry now: The bridge retries through a relay and remembers the host for seven days. The owner sees a quiet “via relay” note.
- 24 Oct · Submit
The draft was refused after a hostname move.
A published plugin’s MCP URL can never change. The draft had to be deleted and recreated on diligence.blackmatter.vc.
In Plugferry now: The address is the first decision on the Bridge tab, with a lock icon and a confirmation before the first upload.
- 25 Oct · Skills
Instructions were cut at 4,000 characters for two days.
Claude and Codex never received the GPT’s tone and opening rules, and nobody could see it.
In Plugferry now: Server instructions take up to 10,000 characters, with a visible count. Nothing is ever cut silently.
- 25 Oct · Test
The model ended a memo with an investment verdict.
It read the memo template, used its own headings, and closed with a recommendation.
In Plugferry now: Advice-adjacent plugins get a suggested no-verdict rule, and review cases describe what must be true rather than exact wording.
- 25 Oct · Package
Two review cases named a tool that no longer existed.
A tool was replaced; the cases still pointed at the old name, and nothing caught it.
In Plugferry now: Expected-tool chips are checked against the active toolset. A missing tool turns red and blocks “Ready to submit”.