Poly A1 · For programmers · diffcall
Other companies' AIs check your change
For the same $2, on your own AI subscriptions: the diffcall plugin in your Claude Code calls AIs from other companies to check your change, shows honestly where they disagree, then fixes it and proves the fix with a test.
Six steps
From the first review to a long run
The steps live in the computer folder, and Claude Code walks them with you. Practice comes first on a small shop with a change that is not merged yet; then the same on your own repository.
The steps and their commands
- Review your change with other companies' AIs · /diffcall:review --diff
- Dig deeper: more rounds and a ready focus — bug hunt, security, regressions, invariants, contracts, hotspots, explain, risk · --rounds 2 --preset bughunt
- Let it fix and prove the fix with a test; move it in or roll it back · /diffcall:fix · /diffcall:judge · /diffcall:rollback
- Connect more AIs: what is installed, signed in and out of date; Google's agy allowed to read · /diffcall:doctor · /diffcall:agy-allow-read
- A long run: leave it, come back, collect it by its number — in Claude Code and in Codex · run_id
- A build from a spec for a night or for days: the spec dictated, the files carry the night, a limit is a pause, the council decides the forks, diffcall checks every milestone · /goal · nightcall · /pocketcall:board
The room, your own seats, the phone
- One page where every seat writes live, a shared draft, tasks with timers, one more seat on a subtask · /diffcall:room
- Any command-line AI of yours as one more seat in the council, checked live · /diffcall:seats
- The board on the phone: every review, fix and judge rings when it ends — done, stopped or resting on a limit, with the judge's verdict right after the fix · /pocketcall:board
- Keys for seats in the Keychain, handed out at each call; the reviewers get no keys of your shell · security find-generic-password
The practice shop ships without its answer key: a reviewer that finds a key next to the code reads the key instead of the code.
What you get
One report, honest about who said what
- Findings
file:line, an input that breaks it, the fix
Each AI opens the folder and reads the code itself. One chair merges the findings, most severe first.
- Who answered
Counted honestly
Names and companies, exactly as they answered. An answer given without reading the files is marked “not counted”; one AI is one opinion, not a council.
- Where they disagree
The value is in what did not match
AIs of one family share its blind spots. The report shows which findings only one company saw.
- The fix
Proved by a test
Fixed in a copy, tests run before and after, checked by a second company. Your project changes only on your word — or the run is rolled back.
Measured
Our live check through the plugin
October 6, 2026: the diffcall plugin on the practice shop from the steps — four hidden bugs in an unmerged change, the same for every AI.
- hidden bugs found4 of 4Codex and Grok each found all four; Google's agy, asked alone, found 4 of 4 as well.
- new findings in the second round7Two rounds with the bughunt focus: the second got the first one's findings and found 7 new ones (8 minutes for both).
- tests green after the fix16 of 16The four hidden bugs and two edge cases of the new coupon fixed in a copy; 12 new tests, 11 of them red on the change; the project untouched until /diffcall:rollback transfer.
- a council over the folder1–2 minA fix with tests and a second company: 49–72 minutes of the computer's work.
- seeded-bug benchmark14 of 14Three small shops, 14 seeded bugs, three live runs: the council caught every bug in all 7 of its runs; one AI alone caught every bug in 9 of 12 — twice the seat did not run, once it answered without a single file:line. Every report, the answer keys and the script ride in the plugin's bench/: rerun it on your seats.
How to start
Two ways
- Through Poly A1
The app sends the folder to the computer
In the app, open “For programmers”, send the folder to yourself, and tell Claude Code:
I'm a programmer. Read FOR-PROGRAMMERS.md in the Poly A1 folder, install the plugins it names and show me the map for programmers.
- Already have the folder
Straight to the steps
Claude Code installs the plugin after your “yes”, then you go from the first step:
/plugin install diffcall@poly-a1-paid
/diffcall:doctor
/diffcall:review --diffThe plugin comes from the catalogue poly-a1-paid that the Poly A1 folder connects.
Questions
Which AIs sit in the council?
By default three: Codex, Grok and Kimi — the AI programs on your computer that you are signed in to. Claude is the chair: it merges their findings and is not a seat by default. Claude and Google's agy join the council when you name them (seats). /diffcall:doctor shows who is in place and what to add next.
Does it change my code?
A review only reads. A fix is made in a copy and moves into your project only on your word, with /diffcall:rollback transfer <id>; every run can be rolled back.
What does it cost?
It is included in the same $2 a month as the lessons. The AIs in the council work through your own subscriptions to them.
Does it work in Codex?
Yes: one line, codex mcp add. A long council answers “still running” with a number, and Codex collects the report by it.
Is it open source?
No. diffcall is our own plugin, shipped inside the Poly A1 folder; its commands are open to read.
Which languages are the steps in?
In all five languages of this site: English, Spanish, Portuguese, Russian and Ukrainian.