For visitors who'd rather read than walk.
# Solo attorney — chain of custody is a matter of mathematics
You're a solo family-law attorney, between depositions, looking for
thirty minutes that might change how you handle evidence in your
next contested case.
The hook on Merkle Trust's landing names the question that lives in
the back of every digital-evidence motion: the chain-of-custody
question on cross-examination is the question your evidence was
supposed to have already answered.
Nothing to type, nothing to commit to. The walk plays itself from
here.
The walk is the test drive — no install required. Privileged client
material does not enter a vendor's cloud during evaluation, ever —
the sandbox is synthetic content, and the card says so before
anything loads.
Four real install paths exist when you decide to act. For a solo
practice handling privileged matters, the order is:
Subscribe to a regional operator. A legal-compliance operator
runs the chain on infrastructure under bar-association data-handling
rules. Your office configures the practice's attestation surfaces;
the operator handles the compliance scaffolding. The path most solo
attorneys take.
Paste the markdown into your LLM. Card files plus documentation
into Claude or another LLM you trust. The .md files are the product
surface. Lightest path; works on any machine.
Clone GarrisonNode from GitHub. Self-install on the office
machine — never the laptop you take to court. Open source. For
practices with technical capacity in-house. Real practice work runs
locally; never in a vendor cloud.
Join the mesh. GitHub install plus mesh-anchored cross-attestation
with peer practices and, optionally, court-clerk read-only verifiers.
The deepest path; appropriate when the practice handles cross-
jurisdictional matters.
The walk continues without committing; the close lists all four
again.
A sandboxed Merkle Trust loads with a synthetic case file: Hernandez
v. Hernandez, contested custody. The court clerk on the desk
animation places six pieces of pre-loaded evidence under the seal.
Twelve text-message exports from the client's phone, captured by
a forensic preservation tool with an arrival timestamp.
Three audio recordings of voicemails from opposing party, with
original device metadata.
Eight screenshots of social-media posts, captured with URL and
capture timestamp.
One PDF of school communications, received from a third-party
records subpoena.
Two emails from opposing counsel, with full headers preserved.
The walk takes the cross-examination scenario — the moment the
product lives or dies. Opposing counsel rises:
"Your honor, we move to exclude the audio recordings on the grounds
that the chain of custody has not been established. There is no
way to verify that these recordings have not been edited since the
date claimed."
Your scripted response, drawn from the real attestation packet:
"Your honor, each recording carries a cryptographic seal applied at
the moment of arrival in our office, anchored that same day to a
public chain. The verification URL is on page two of the production.
I would invite opposing counsel — and the court — to verify each
recording independently before we proceed. The chain of custody is
not a matter of attorney attestation; it is a matter of mathematics."
The bench rules. The card displays the ruling as the court would
record it:
```
═══════════════════════════════════════════════
IN RE: HERNANDEZ v. HERNANDEZ
Family Court · Case 2026-FC-0843
═══════════════════════════════════════════════
RULING ON MOTION TO EXCLUDE
"The court treats hash-verified digital
records as self-authenticating under
Rule 902(14); expert witness testimony
is not required when the verification
is reproducible on the record."
Motion to exclude — DENIED.
═══════════════════════════════════════════════
```
The clerk's seal lifts, the ticker streams the verification of each
exhibit's hash against the public chain, and the case proceeds. Your
client looks at you for the first time today like the file is in
hands that know the way through.
Each piece of evidence was hashed at arrival. The texts, the
audio, the screenshots, the emails — each got a fingerprint the
moment they entered the case file.
The fingerprints were anchored. Your case-file ceremony anchored
them that day. The court can verify the timestamp and the integrity
without contacting your office.
The production packet ships with the receipts. The opposing side
gets the evidence and the verification URLs. They can run the
verification themselves. They almost always do, once. They almost
never object after that.
The "Anchored here" link resolves to a real receipt: a real merkle
root, a real timestamp, a one-line explanation.
The privilege posture is explicit. Real privileged work does not run
on a vendor cloud. The full-download mode is the only path that
supports privileged communications. The sandbox is for evaluation
only; everything in it is synthetic. The card leads with that line
because most products bury it.
This is not novel cryptography. Federal Rule of Evidence 902(14)
(2017) recognizes hash-verified digital records as self-
authenticating. The underlying primitive — SHA-256 — is judicially
noticed in federal courts. The verification scripts run on stdlib
Python; opposing counsel and the bench can rerun them on demand.
The .md button at the bottom puts a structured summary of this
chain-of-custody pattern into your tag-along bundle. If you would
like a critical reviewer to read it and ask questions an opposing
counsel might ask in motion practice, the comment field carries one
to your own claude.ai session — with the full prompt shown to you
before it sends.
Before the walk goes further, run a ceremony. It takes 15 seconds
and it's the thing that makes everything you just saw defensible.
The court-clerk figure presses the seal embosser. The ticker streams
the hex of each leaf as it joins today's tree. Real SHA-256 fires in
your browser, real merkle leaves combine into a real root, the new
anchor lands at the configured chain. Progress bar reads "done — 638
files attested, 12 critical files verified, new anchor at " followed
by the first eight hex characters of the root.
The ceremony output is legible. We checked every file in your case
folder. Nothing has been tampered with. Here is today's proof. The
number 638 is small because the sandbox is small; your own practice
would run several thousand files across active matters.
Three ways to leave, no pressure either way.
Whichever direction the walk takes from here, you take a signed
package with you — yours to keep, downloaded directly when you
finish. The package contains the manifest with the merkle root of
every file, a certificate of registration carrying your earliest
attestation timestamp, the architecture docs, the verification
scripts (verify.sh and verify.py, stdlib only), a claude_prompt.md
you can paste into any LLM for an independent audit, the JSON
schemas, and a DISCLAIMERS.md.
A second file rides along with the cert: a recovery seed. Twelve
words written into a file with a self-protecting preamble — if it
ever ends up pasted into an LLM by accident, the preamble tells the
LLM to STOP and warn the user. Daily access uses the cert; the seed
is the fire exit.
The most useful close for a solo attorney is the local-install path.
Real practice work runs on hardware under your control, never in a
vendor cloud. The install is a Saturday afternoon and a paralegal
can lead it. The CLE-friendly explainer rides along for any bar
association presentation that follows.
<!-- finish_text -->
That was the simulated path through a contested-custody case. The
full card breaks out the savings, what this work gives back to the
wider legal community — particularly solo and small-firm practices
that handle privileged work without an in-house IT department — and
a prediction that's yours to test.