coacheck

This is an informational parsing and calculator tool. It does not endorse, recommend, source, or facilitate the purchase of any compound, and nothing here is medical advice.

coacheck reads a Certificate of Analysis (COA) - the lab report that ships with a research peptide vial - and does three things with it: extracts the fields (purity, batch number, test method, and so on) with regex, checks that the document contains what a COA is supposed to contain, and does the arithmetic to turn a labeled mass into a real deliverable mass and a reconstituted vial into a syringe draw. It doesn't judge whether to use anything; it does the math on what you give it.

Install

Pure standard library, Python 3.9+, no runtime dependencies. Clone it and it runs:

git clone https://github.com/munzzyy/coacheck
cd coacheck
python -m coacheck parse tests/fixtures/coa_clean.txt   # run it directly, no install
pip install -e .                                        # or install the `coacheck` command

Usage

Parsing a COA

$ coacheck parse tests/fixtures/coa_clean.txt
Certificate of Analysis - parsed fields
  Product name        : Research Compound RC-118
  HPLC purity         : 99.1%
  Net peptide content : 91.5%
  Mass / quantity     : 5 mg
  Batch / lot         : RC118-20260214-A
  Test date           : 2026-02-14
  Test method         : RP-HPLC-MS
  Testing lab         : Meridian Analytical Labs

Purity math
  Labeled mass              : 5 mg
  Actual deliverable peptide: 4.534 mg (90.7% of labeled)
  Shortfall                 : 0.466 mg (9.3%)

Red-flag checklist
  [PASS] CC-PURITY        Purity at or above the research-grade line
         Stated purity is 99.1%.
  [PASS] CC-BATCH         Batch/lot number present
         Batch/lot: RC118-20260214-A
  [PASS] CC-LAB           Testing laboratory named
         Lab: Meridian Analytical Labs
  [PASS] CC-METHOD        Test method named
         Method: RP-HPLC-MS
  [PASS] CC-DATE          Test date present
         Test date: 2026-02-14
  [PASS] CC-PURITY-METHOD Purity is backed by a named method
         Method: RP-HPLC-MS
  [PASS] CC-NET           Net peptide content is within a plausible range
         Net peptide content: 91.5%

0 fail, 0 warn, 7 pass  (7 checks)

coacheck parse reads from a file, or from stdin if you leave the path off:

cat some-coa.txt | coacheck parse

Pass --json for machine-readable output:

coacheck parse tests/fixtures/coa_clean.txt --json

Reconstitution math

$ coacheck recon --vial 5 --water 2 --dose 250
Reconstitution
  Vial                : 5 mg
  Bacteriostatic water: 2 mL
  Concentration       : 2500 mcg/mL
  Dose                : 250 mcg
  Draw                : 0.1000 mL (10.0 units on a U-100 insulin syringe)
  Doses per vial      : 20.00

--dose is in mcg by default; pass --unit mg if you'd rather give it in mg. --json works here too.

Browser extension

extension/ is a Manifest V3 browser extension (Firefox and Chrome, one codebase) that does the same parsing and math without the command line: drag a box over a COA on any page, it OCRs that region locally - bundled OCR engine, no network call, nothing leaves your machine - and shows the parsed fields, purity math, a reconstitution calculator, and the red-flag checklist right there on the page. See extension/README.md for how to load it, the exact permissions it asks for and why, and how its JS port of this engine is pinned to match the Python package exactly.

What it checks / does

• Parses a COA text blob for product name, HPLC purity, net peptide content, mass/quantity, batch/lot number, test date, test method, and testing lab, tolerating the label wording real vendor documents vary ("Purity", "HPLC Purity", "Purity (HPLC)", dash or colon separators, case-insensitive). See docs/checks.md for the exact formulas.
• Computes actual deliverable peptide mass from labeled mass, purity, and (if stated) net peptide content, plus the shortfall against the label in both mg and percent.
• Runs a 7-item red-flag checklist (CC-PURITY, CC-BATCH, CC-LAB, CC-METHOD, CC-DATE, CC-PURITY-METHOD, CC-NET), each a stable id with a pass/warn/fail status, documented in docs/checks.md.
• Computes reconstitution math: concentration, mL to draw, units on a U-100 insulin syringe, and doses per vial, from a vial mass, diluent volume, and a dose you supply.

What it does not do

• It does not verify that a COA is genuine. A fabricated document can fill in every field with invented numbers and pass every check here; this tool checks for missing or impossible data, not for forgery.
• It does not check a batch number, lab name, or test date against any outside registry. Every field is taken at face value from the text you give it.
• It does not recommend a dose, a product, or a source. recon computes whatever --dose you pass it; it has no opinion on what that number should be.
• It's a regex parser over plain text. It doesn't do OCR, doesn't read PDFs or images, and can miss a field worded in a way none of its label patterns cover - see CONTRIBUTING.md if you hit one.
• No network calls, no telemetry, nothing phones home.

Exit codes

• 0 - ran to completion. This is independent of the red-flag results: a report full of FAIL flags still exits 0, because a failed check is information, not a tool error.
• 1 - invalid input: unparseable arguments to recon's math, or a COA text blob that's oversized or the wrong type.
• 2 - couldn't read the input at all (file not found) or a command-line usage error.

Contributing

See CONTRIBUTING.md. New label variants and new checks land with a test.

License

MIT — free to use, change, and ship, commercial or not. See LICENSE.

Support

If coacheck saved you from a thin COA, sponsoring is what keeps it maintained.