groundwork ⛰️🔬

Your agent can hand you a paper by morning. The harder question is whether the project should have existed — and that one is answerable in ten minutes, before the night is spent.

A full research pipeline for coding agents — direction, gate, experiment, claim, paper, submission, memory — with the stage every other toolkit is missing: one that returns NO-GO.

git clone https://github.com/GuoCheng24/groundwork && cd groundwork
python -m groundwork gate --baseline 0.812 --oracle 0.830 --se 0.019      # NO-GO, in ten seconds

As a plugin, inside Claude Code — the seven stages, no clone, no PATH:

/plugin marketplace add GuoCheng24/groundwork
/plugin install groundwork

Codex CLI reads the same seven files rather than a parallel mirror, so the two cannot drift apart. The stages name the command-line tools and work without them; to add the tools:

pip install groundwork-research

Python 3.9+, no dependencies, nothing to configure. Works with Claude Code, Codex CLI, DeepSeek, Kimi, or any agent that reads Markdown and runs a shell.

Never used a coding agent before? → Getting started · 上手指南（中文） → A worked example — one direction, from idea to killed, in an afternoon. It ends in a NO-GO, which is the outcome this exists to produce cheaply and the one no other walkthrough shows you.

From installing Claude Code or Codex to running a whole project with one — including the case every other tutorial skips: a shared cluster node with no direct route to the internet. The reverse tunnel, the no_proxy entry that makes git clone hang on a socket that will never open, why the IDE panel disconnects while the CLI on the same machine is fine, and how to share a GPU node with people who are not you.

command	what it does, or refuses
groundwork init	starts a project whose first section is the gate, left empty on purpose
groundwork night	an overnight loop optimised for not stopping — here the first non-zero exit ends the night, and the morning report says which steps therefore never ran
groundwork check	a sweep that reports a pass because there was nothing to check, and an exemption that quietly disarms the check next to it
groundwork gate	a direction whose ceiling, baseline, random arm or positive control already answers it
groundwork lit	an occupancy verdict when the index that would have found the competitor did not answer
groundwork prereg	a pre-registration that version control says is younger than its own results
groundwork probe	which answering for PATH and being read as an answer about the machine, and a filesystem crawl that did not finish being read as an absence
groundwork cluster	a card whose free memory is somebody else's leftovers, and one arm split across two GPU models
groundwork shard	work split so that a restart takes an item twice or not at all, and a merge that quietly keeps one of two different answers for the same item
groundwork watch	a run that was never alive, an empty log read as silence rather than buffering, and a watch that dies with the session that set it up
groundwork ledger	a cause of death that is free text nobody can count
groundwork stats	the exact interval, the exact paired test, the smallest effect the split can resolve, and BH against BY — so nobody re-implements them
groundwork noise	a difference being quoted without the spread of the instrument that produced it
groundwork reach	a bot-challenge page being read as a paper
groundwork install	attaches the stages to Claude Code, Codex, or anything that reads Markdown
doubleblind	a number that exists in no file, a brief that tells the reviewer what to conclude, a caption nobody can read

Every one of those refusals exists because the unrefused version shipped.

The pipeline

 00-gate ──▶ 10-direction ──▶ 20-experiment ──▶ 30-claim ──▶ 40-write ──▶ 50-submit
   │             │                  │               │            │            │
 refuse      candidates       pre-register,     three layers   claims     compliance,
 the         that can         seal, commit,     blind to       first,     rebuttal,
 direction   survive it       then launch       different      figures    resubmit,
                              across idle       defects        audited    talk
                              GPUs
   └────────────────────── 90-memory: the archive of what died, and why ──────────┘

 groundwork check ── runs every gate above over a project, in one command

Seven stages, 50 files. Each stage decides whether you are allowed into the next one: a menu asks you to know which skill to call, a gate tells you.

Every file carries the failure that produced its rules, because the rules are not obvious and the failures are what make them stick — a scorer that moved 0.37 points on a file that never changed, a preview renderer that lies in both directions, an occupancy search that invented its own competitor, a pre-registered "clean hardware test" that was not clean until a control existed.

---

What is in each stage

stage	what it decides	notes, each written from a failure
00-gate	Gate — the four numbers that decide	breakthrough · ceiling-first · metric-validity · positive-control · two-toolboxes
10-direction	Direction — candidates, not ideas	kill-argument · lit-review · occupancy · originality · venue-fit
20-experiment	Experiment — sealed first, then launched	ablations · data-hygiene · post-training · hardware · implementation · long-runs · shared-machine
30-claim	Claim — three layers, blind to different things	citations · integrity · review-loop · statistics
40-write	Write — from claims, not from results	build · captions · claims · diagrams · figures · structure · theory
50-submit	Submit — and everything after	compliance · delivery · patent · rebuttal · resubmit · talks
90-memory	Memory — the archive is the asset	postmortems · wiki

The gate: four numbers, ten minutes, before anything

$ groundwork gate --baseline 0.812 --oracle 0.830 --se 0.019

  headroom            +0.0180  (oracle 0.8300 - baseline 0.8120)
  one standard error  0.0190
  headroom in SEs     0.95
  smallest detectable 0.0532  (80% power, two-sided 0.05)

NO-GO.
  * Headroom is 0.95 SE, under the 2 SE this gate requires. Even a method that
    captured the entire gap would not separate from the baseline on this split.

Record it in archive/ with the cause, so the next person who has this
idea - including you, in four months - finds the verdict before the work.

Four measurements, on the same split, before the first real experiment:

#	measurement	what it rules out
1	strongest trivial baseline, tuned as hard as the proposal	the signal was never structural
2	oracle — perfect access to whatever the proposal estimates	there was no headroom to win
3	random arm — shuffled labels or random assignment	the task never needed a learned policy
4	positive control — a case where the effect must be recovered	a null would measure your pipeline

The gate does not ask what the method is. A gate that knows what you are hoping for is not a gate.

It refuses when headroom is under two standard errors, when a perfect method would still be reported as null on this split, when the random arm reaches the baseline, or when the positive control does not recover. When it passes, it prints the share of the headroom a method must capture to be detectable at all — a number worth knowing before the work rather than after.

---

The two sentences that make this a gate rather than advice

One project measured its oracle ceiling in its tenth session. The ceiling was closed — there was nothing for any method to win. Measured in session one, every conclusion of that project was available in a day, and the other nine sessions need never have happened.

A later project did measure the ceiling on day one and saw an apparent 2.7× of headroom, so the gate passed. The baseline it compared against was its own, untuned. The right comparison — three numbers read straight from the same region of the same data — beat the oracle ceiling by 0.047. The project should have died that morning. It went on to pass six further adversarial checks over two weeks, and not one of them asked whether the control had been tuned. Given the same budget, the final gain over that baseline was −0.0024: indistinguishable from nothing, in the wrong direction.

So the rule has a second half, and it is the half that matters: the baseline gets the same tuning budget as the method. A baseline nobody tried to make win is a strawman with error bars. See groundwork/skills/00-gate/ceiling-first.md.

The archive: ten ways a direction dies

archive/causes-of-death.json records ten, each with the cheap test that would have ended it sooner and what it cost when it did not. They are not hypothetical:

cause	what happened	cost
ceiling too low	the method worked; an oracle beat the baseline by 1.6–1.8 points, so the whole space available to any method was inside the noise	weeks
a thick baseline absorbed it	a structured encoding reproduced across cohorts; a dense local baseline with no structure reached the same number	weeks
positive control collapsed	the main analysis returned a clean null, and so did the case where the effect is known to exist	the whole study
reduces to known	a failure mode that looked new was a known balance condition under a change of variables	weeks
already occupied	a qualitative mechanism published in 2017, its closed form in 2003	days–weeks
a random arm won	every learned repair policy was compared against the others and looked ordered; random assignment beat all of them	weeks
external validation collapsed	strong in development, absent in the external cohort	months
our own supplement	the "new paper" was a table in the group's own supplementary material	days
leakage flattered it	perfect discrimination from selecting features before splitting; redone correctly, chance	a submission
its ceiling was a smaller venue	it genuinely worked, and both routes to a flagship claim collapsed onto things already known	a rejection cycle

Directions die in batches. One programme killed 32 of 32 candidates at this stage; another 16 of 16. That is the gate working — but only if the verdicts are written down.

---

The occupancy gate: a silent index is not an empty literature

$ groundwork lit occupancy "bfloat16 batch invariance importance ratio" -n 6
 1. 2025  ...
 ...
# backends: arxiv: ok, openalex: NO ANSWER, semanticscholar: ok

# ====================================================================
#  NO VERDICT AVAILABLE. The primary index did not answer, so this is
#  a preprint-only search. "Nothing occupies this" cannot be concluded
#  from it - a spent quota and an empty literature look identical.
# ====================================================================

That refusal is the whole point of the tool. The first version degraded silently to a preprint-only search and printed the results as though the search were complete — and the answer a spent quota produces is "nobody has done this", which is the most expensive wrong answer available at this stage.

lit also carries the three traps in checking that a paper exists at all:

• an occupancy search can invent its neighbours, so every candidate that matters is verified separately;
• a verifier that fails on the network reports a hallucination — a batch of failures at once is a network diagnosis, and lit verify returns a distinct exit code for it rather than a verdict;
• "that identifier looks too recent to be real" is relative to today's date, and has produced false accusations against real papers. The current year is resolved at run time, never written into the code.

And lit journal reports a venue's citation metrics with the caveat attached, because one such figure quoted from memory once mis-set a venue choice by a factor of two — and the freely available proxy was itself off by a factor of three from the official number.

The experiment stage: sealed first, then launched

groundwork prereg new prereg/PREREG_run3.md --title "run 3"   # six required sections
groundwork prereg seal prereg/PREREG_run3.md
git commit -m "Pre-register run 3"                              # BEFORE any generation
...
groundwork prereg verify prereg/PREREG_run3.md --results results/metrics_run3.json

verify checks the seal, checks every section is filled in, and checks with git that the pre-registration was committed before the results it governs.

  FAIL results.json was committed BEFORE the pre-registration was committed.
       A pre-registration written after its results is a write-up.

The six required sections are the six that get quietly dropped: what is held fixed, what changes, the pre-stated analysis, the stopping rule, what gets written if it comes out the other way, and what was already known when this was written. That last one is not a confession box — an arm launched after seeing a partial score is not disqualified, an undisclosed one is.

and launched wherever the GPUs actually are

$ groundwork cluster survey --nodes gpu01 gpu02 gpu03 gpu04
gpu03:
   [0] NVIDIA L40                   16.2 GB free of  45.0   util  97%
   [1] NVIDIA L40                   48.0 GB free of  48.0   util   0%   idle
...
14 idle card(s) across 3 reachable node(s).

$ groundwork cluster plan --nodes gpu01 gpu03 --need-gb 20 --shards 4 \
      --command 'python eval.py'

Three habits, each learnt by losing a night: somebody else's job is not free memory (a card with 5 GB free is not idle, and a job placed there dies at 3 a.m.); leave a card per node, and leave an idle one rather than the scraps; and one arm, one GPU model — plan refuses to split an arm across models unless told the split is only a throughput knob.

That last refusal is not caution. The same weights, the same seed, greedy decoding, the same batch size and the same scorer, on two different GPU models, scored 76.89% and 75.42% — 1.48 points from changing nothing but the card. The same arm repeated on a second card of the same model reproduced 541 of 541 generations byte for byte.

Before either: what can this machine actually do

$ groundwork probe
  GPU        6 card(s), 0 idle
  /dev/shm   126 GB, 0.3 GB used - this is RAM, and it is charged to you
  on PATH    git ssh rsync nvidia-smi gcc pandoc tectonic gh jq
  modules    69 in `module avail` - a catalogue that is deliberately not on PATH
  INSTALLED BUT NOT ON PATH - `which` says no and the machine says yes:
             ninja:   .../envs/af3/bin/ninja
             soffice: .../tools/lo76/opt/libreoffice7.6/program/soffice
  isolation  unprivileged user namespaces: yes; bwrap fuse-overlayfs podman
             /dev/kvm no, cgroup v2 delegation no
             so: file-system and process isolation without root, but no VM.

Both of those were real. soffice was declared unavailable for weeks on the strength of which soffice returning nothing, while LibreOffice sat eight directories deep under a shared mount; documents were checked with an approximate renderer that under-reported overflowing text. ninja was missing from PATH when an inference stack's JIT backend shelled out to it, and the run was worked around instead of fixed. A negative from which is a statement about PATH.

So is a negative from a filesystem crawl, and probe says which: it names the roots it searched and the depth, lists the large mounts it did not search, and if the crawl hit its time budget it says the results are unfinished searches rather than absences. On a cluster the fast door is the module system, which is where probe looks first.

The third block is the one that reopens work. "No root, so no containers" was written down here as a constraint and was simply false: unprivileged user namespaces, bwrap and fuse-overlayfs were all available.

Split it so a restart loses nothing

$ groundwork shard merge 'out_s*.jsonl' --expect 2638
  out_s0.jsonl: 528 rows
  ...
1595 distinct id(s)

SHORT BY 1043: expected 2638. A shard that died leaves a hole that no file
reports, because every shard file is complete on its own.

The rule is one line, and it is the whole tool: slice the item list before filtering out what is already done. Slice afterwards and ownership depends on how far each shard happened to get — restart two shards at different points and they take the same item while a third is taken by nobody. Nothing errors, and every shard file is internally consistent. shard plan prints that line in the shape your harness needs it, and a test demonstrates the wrong order producing both the overlap and the orphan rather than asserting that it would.

merge refuses two different answers for one id, naming the fields that differ. That is not a duplicate to be deduped: two runs produced different answers, and which one survives depends on the order the files were listed in.

Then launch it so that it outlives the session

$ groundwork watch start --name run3 -- python eval.py --shard 0/4
started run3 (pid 41883)

waiting 90s before believing it started...

IT IS ALREADY GONE (exit 1). The head of its log:

  | weights not found

Ninety seconds, not zero: a job that fails to load its weights looks exactly like a job that is training, at launch. When the head of the log is empty, watch says so as buffering rather than as silence — those two look identical from outside, and only one of them loses everything in a crash.

When the run ends, groundwork watch status writes archive/runs/<name>.DONE with the verdict, and exits non-zero if the log holds a traceback, an OOM, a Killed or a NaN. The flag file is the point. A watch set up inside an agent session dies with that session, and its silence is indistinguishable from "nothing has happened" — one such watch here went unread for forty hours. A file is read by whoever comes next; an intention is not.

The tool's own first version had the bug it exists to catch: os.kill(pid, 0) succeeds for a process that has exited and not been reaped, so a job that died one second in was reported as alive. Both directions are now in CI.

---

One command that runs all of them

$ groundwork check
  n/a   gate          no PROJECT.md, so no recorded gate
  ok    prereg        2 sealed pre-registration(s), every required section filled
  ok    prereg-order  2 entered the record before the results they govern
  FAIL  noise         results are being compared with no measured noise floor
                      -> groundwork noise --n 10 --command '<your scorer>'
  waiv  raw-data      the generations are the artefact here; they are 3 MB and versioned
  ok    private       61 tracked file(s) scanned, nothing private found

  3 ok, 1 failed, 1 not applicable, 1 waived

Three decisions make this more than a checklist.

n/a is printed as loudly as FAIL, and it is not a pass. A sweep over a project with no pre-registration must not show a green tick: a check that passed because there was nothing to check has told you the opposite of the truth. Most sweeps of this kind are mostly n/a on a young project, and that is the reading.

A waiver names its check and carries a reason, and the reason is reprinted every time. A flat exemption list is how a repository disarms itself — an entry written for one document silently exempted a deliberately broken second one here, and the CI step whose job was to fail started passing. A waiver in archive/waivers.json with an empty reason does not waive anything.

It scans what git would carry, not what git already carries, and it says what it scanned against. A scan restricted to tracked files passes right up to the moment you git add, which is the moment it exists for; ignored files stay out, because a scan that shouted about a 30 GB generations file would be turned off. What counts as private is partly project-specific — a cluster's node names, an internal ticket prefix — so a project declares its own patterns in archive/private-patterns.json, and every clean result names how many patterns it applied rather than just saying nothing was found.

It refuses to accuse. A pre-registration written to another template is reported as not judged by name, not as incomplete — deciding whether prose answers a question is not something a name match can do, and a sweep that guesses generates false accusations against documents that do answer it. The checks that stay are the ones that can be decided mechanically: is there a seal; did version control see the plan first; is the noise floor on disk; is a home path about to be pushed.

Two of those were found by running the sweep against this author's own repositories. prereg verify had been asking when a pre-registration was last committed, so redacting a machine name from a sealed plan moved it forward past its own results and the tool called a correctly pre-registered study a write-up. And a sha256 appearing inside a document was being taken as its seal — impossible, since a file cannot contain its own digest; the digest in that document belonged to the plan it amended.

---

The night

Every toolkit in this space has an overnight loop, and the thing they all optimise is not stopping. That is backwards. A night is expensive because of what it commits you to in the morning, not because of the GPU hours: an arm that ran all night on a wrong flag produces a table, and the table gets believed.

$ groundwork night run docs/night-plan.txt --name fullset

[prereg] groundwork prereg verify prereg/PREREG_fullset.md --results results/
  rc=0  0.0 min

[capacity] groundwork cluster survey --nodes gpu01 gpu02 --need-gb 20
  rc=1  0.2 min
  | 0 idle card(s) across 2 reachable node(s).

The night stopped at [capacity]. That is the tool working: the step exited
non-zero and nothing downstream ran on top of it.

night runs a plan in order and the first step that exits non-zero ends it. Every tool here is built to exit non-zero at the right moment — gate on a direction with no headroom, prereg verify on a plan younger than its results, shard merge on a hole or a disagreement, noise on a scorer that fails, check on a gate with nothing behind it — and night is what makes those exits matter while you are asleep.

What you read in the morning is a report that says where it stopped, the lines from the log that say why, which steps therefore never ran, and the one command that continues after you have fixed it. The steps that did not run are the point: they are what the morning is still free to reconsider.

A worked plan is in docs/night-plan.txt — the full-set arms of a benchmark reproduction, gate chain and all.

And when every step passes, the report says so in the only way that is true: the commands succeeded, which is not the same as the result being right.

To be told rather than to remember, --notify takes a shell command:

groundwork night run plan.txt --notify 'curl -sf -X POST "$WEBHOOK" -d "$GROUNDWORK_SUMMARY"'

No messaging vendor is built in — a webhook is a curl, a message is a mail, a desktop bell is a notify-send, and a tool that ships one integration ships a token to store and a vendor to follow. The command is handed the verdict in its environment, and its exit code is reported: a notification that fails silently is worse than none, because you are then waiting for a message that is not coming, and the file that would have told you is the one you have stopped checking.

---

The claim stage: three layers, blind to different things

layer	finds	cannot see
re-derivation	a number that exists in no file; a bound stated tighter than the interval	a correct number inside a sentence that does not follow from it
a reader with no context	claims that do not follow; a comparison pointing the wrong way	a fabricated number that looks plausible
the rendered figure	labels that read as one word; a caption unreadable at the size it will be seen	whether the shape a reader takes from the figure is the shape the data supports

Implemented in doubleblind, installable on its own. Its ledger records 22 real defects with the layer that missed each one; 10 were caught by a person looking at the rendered artifact, which is the number the third layer exists to shrink.

And the rule that decides what to ask a reviewer: ask what the evidence supports, never ask it to verify that X. The first question has the answer in it, and doubleblind lint finds the phrases that carry it before the request is sent.

---

Where every rule was paid for

Not a bibliography — repositories where these rules run in CI on every push.

repository	what it demonstrates
batch-logprob-gap	the same measurement on three GPUs across two architectures; the effect is on all three and fp32 removes it on all three; the control is a re-run of the original card that must reproduce it cell for cell
ifeval-reproduction	a pre-registration chain CI re-hashes on every push; an official scorer measured against itself — ten runs on one unchanged file span 0.37 points and disagree on 2 prompts of 541
taichu-eval-reproduction	a reproduction whose verdict turns on 16 truncated generations — the card's number is inside the interval under one scoring and outside it under the other, measured on all 1,000 items rather than argued from a subsample, and the page says so
doubleblind	the three claim layers, each with a test asserting the defect it cannot catch

---

Using it with your agent

The stages are plain Markdown under skills/ — no framework, no MCP server, no second subscription.

• Claude Code — ln -s .../groundwork/skills/* .claude/skills/, then ask for a stage by name.
• Codex CLI — codex exec < groundwork/skills/00-gate/SKILL.md for a fresh session.
• DeepSeek / Kimi / any OpenAI-compatible endpoint — the skill file is the system prompt; the tools are shell commands.

See adapters/ for the exact invocations, including how to get a reviewer that is genuinely a different model for the claim stage.

---

What is here, and what is not

groundwork is not a promise that an agent will produce a publishable paper unattended. The gate exists because most directions should not be started, and a pipeline that never returns NO-GO is selling something.

It is also not, today, a drop-in replacement for the largest generative toolkits. Honestly, side by side with ARIS, which is careful work and worth using:

	ARIS	groundwork
a stage that returns NO-GO before the work	—	yes, from four measurements
an archive of how directions die, each with the test that would have caught it	failed ideas as anti-repetition memory	ten causes, with the cheap test and the cost
pre-registration version control can date	—	yes, and it fails when the results are older
multi-node idle-GPU placement, shard ownership that survives a restart	one configured server, vast.ai, Modal	yes, and it refuses to split one arm across two GPU models
checking a training run	training-check	narrower and measured: one file on RL post-training, where the importance ratio leaves [0.9, 1.1] for 1.8–60.0% of tokens with the policy unchanged, flips the PPO clip decision for 1.68–10.11%, and — across six GRPO arms, two seeds, 150 steps — does not reach the reward. Both halves, because the first half alone sells a week of fp32 plumbing
launching a long run and being sure it started	run-experiment, monitor-experiment, an experiment queue	yes, and the check is the point: ninety seconds before believing it, the log head read back, an empty head called buffering rather than silence, and a flag file that outlives the session so the watch is not an intention
finding out what the machine can actually do	—	yes — including what is installed but not on PATH, the module catalogue, whether isolation without root is available, and which large mounts it did not search
running every gate at once, over a project	meta-optimize over an event log	yes, check — and it reports n/a as loudly as FAIL, because a sweep that passes for want of anything to check has told you the opposite of the truth
verification layers blind to different defects, each with a test asserting what it cannot catch	an LLM review gate with an un-forgeable reviewer-identity chain	three layers, no MCP required
literature ingestion (OpenAlex, Crossref, arXiv, Semantic Scholar)	yes, several skills	yes, one tool — re-ranked, and it refuses an occupancy verdict when the primary index is silent, because a spent quota and an empty literature look identical
a record that compounds — what died, what got through, what converted into a check	meta-optimize reads an event log	yes, ledger, with a closed taxonomy so the causes can be counted
paper compilation and reference style	yes	yes, and two files deeper: the failures that compile cleanly — a centred over-wide table that never warns, a font declaration that never reaches the preamble, a bibliography hyphen that is not a hyphen
producing the Word copy — where a starred table vanishes without a trace, and why extracting the XML text cannot see it	—	yes
Overleaf sync specifically	yes	no — the editor's API is not covered; the LaTeX and Word production path is, in much more depth
renting GPUs — vast.ai, Modal, a serverless backend	yes	no, and deliberately: this has never been run here, and a file written from a vendor's documentation would be the one file in this repository not backed by something that happened. cluster assumes you can ssh to a GPU; if you cannot, ARIS covers that and this does not
installable as a plugin	yes	yes, and from one source: the Claude Code and Codex manifests point at the same seven stage files, so there is no mirror to fall behind
being told when it ends	feishu-notify	night --notify takes any shell command — a webhook is a curl — and reports the notification's own exit code, because a message that failed silently leaves you waiting for one that is not coming
submission portals — the field that picks your reviewers, eligibility rules, what anonymity actually leaks	—	yes
slides, posters, talks	yes	yes, two files: the talk, and the production discipline — a deck was 17 pages in one renderer and 11 in another, and the converter is usually installed but not where a plain lookup finds it
theory track	proof-orchestrator, proof-writer	yes, one file: attack a stated open problem, and the three ways a result turns out to be known
grant proposals	yes	yes — the gate applied before the proposal, "why you" as a checkable question, and the preliminary result that was designed to be reportable either way
handing a manuscript to a human collaborator — tracked-change formatting regressions, orphaned equation objects, reference-manager fields, metadata that leaks through the explanation document	—	yes, from a manuscript delivered round after round and found unclean each time
caption audit — panel letters, a stated direction that is backwards, a colour encoding that contradicts the discussion	—	yes

| patents | five skills | two, from a live prosecution: the four orderings that cannot be undone, and the disclosure document an attorney actually drafts from |

If you already use ARIS, the useful move is not to switch. Run groundwork gate before its pipeline starts, and the 30-claim layers before anything leaves. Those are the two places it has nothing, and they are the two places the expensive mistakes are.

Licence

MIT.