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ARANTHOS
AranthosAranthos
Independent, external and deterministic behavioral measurement and forensic evidence for autonomous systems

Every behavior, measured. Every measurement, sealed. Every departure, a finding. Every finding, the team's call.

Aranthos measures the behavior of autonomous systems in production against their own learned baseline, zero AI and seals the proof. See drift as it happens. Prove what happened, years later, to anyone. Or that nothing did.

A model's opinion is not evidence.
A pencil study of a behavioral field: a dense cloud of on-plan systems, and one trajectory departing in red.A pencil study of a behavioral field: a dense cloud of on-plan systems, and one trajectory departing in red.
One departure, designated
Plate 00 · The instrument, live UTC 00:00:00.000
DRIFT HEALTH INDEX (DHI) · PRICING-DESK-11 84 Stable
ExternalNo SDKIndependentRead-onlyDeterministic
The instrument · Specification
READS · ACTIONS, TOOLS, SCOPES, OUTPUTS, TIMING · NEVER THE PROMPT · NEVER THE WEIGHTS · NEVER INTERNAL STATE
§1 · SEE · Drift Health Index

One number per system.

The first risk of an autonomous system in production is not the courtroom. It is the system drifting from its own normal, quietly, at production speed, while the infrastructure dashboards stay green.

DHI · DRIFT HEALTH INDEX · 0 TO 100 HIGH IS HEALTHY

Aranthos measures the distance between what the system is doing and what it normally does, live. Zero AI in the measurement loop.

The Drift Health Index (DHI) is a computation. It is not a model grading a model, and anyone owed an answer, a second line, an auditor, can recompute any value from the sealed record and land on the same score.

The instrument, live One number per system · Learned, then read
SOURCE
STANDING BY
00:00:00.000000 UTC LEARNED BASELINE · PROVABLE, POINT BY POINT RAW TRACES · LIVE, IN ORDER
··
DHI · ONE NUMBER
LEARNING
DESIGNATED
TOOL DRIFT
READ ONLY · THE INSTRUMENT OBSERVES AND RECORDS, IT NEVER ACTS 0 TO 100 · HIGHER IS HEALTHIER · EACH SYSTEM ITS OWN BASELINE
DRIFT WARNING STABLE 0 40 70 100 PAYMENTS-DESK-EU
2:20 PM FIVE STEPS, REPLAYED SLOWLY · CLICK ANY STEP
§2 · Route · Findings to the teams

Not an alert. A finding.

Drift does not announce itself. Most teams learn about it downstream, from a reconciliation, a complaint, a number that stopped making sense, hours after the departure began.

AN ALERT

Something is wrong, somewhere.

It hands the team the investigation
A FINDING

Which system. Which dimension departed. Since when. Against which learned baseline.

Fires on measured departure from its own normal · Never a generic rule
Plate 01 · The route to the team, live
Plate 01 · One departure: measured, composed, designated to the operating team
THE HOUR

The first hour of an incident is spent finding out what is happening. Here, it is spent deciding.

THE AUTHORITY

It carries no invented severity and does no triage in the team's place: the finding says where to start, the decision stays with the team.

THE ROUTE

Findings route to where the teams already work.

splunk>
§3 · Connect · Aranthos Connect

Aranthos Connect: the full-fidelity path.

Our endpoint speaks OpenTelemetry: the open standard already emitted in production.
Nothing proprietary in the way.

Fidelity is decided at the tap point, not by the tooling.

BEFORE THE SAMPLER

Tapped before the sampler, the record is one to one, with a leading platform or nothing at all: the existing OpenTelemetry collector adds one export, nothing of ours is installed.

DOWNSTREAM

Tapped downstream, or read back from a dashboard, the record inherits the sample.

AT ANY LIMIT

Everything saturates somewhere. What matters is what happens there: no sampling, and at any physical limit, a signed gap instead of a silent drop.

The cost of sampling, as documented

Lossless. Zero sampling.

Tools built for monitoring keep a sample. That fits dashboards. Proof needs the opposite: the first hostile question is what the sample left out.

about 10 traces /s

the default target of a leading platform's automatic sampling

15 minutes

the only window where 100% of ingested data is queryable before retention filters

1%

the default flat retention sampling, plus a representative selection

as documented by a leading platform · verified July 2026

There, completeness is a cost. Here, it is the product.

Sampling drops events by design. Evidence writes a signed gap.

THEIR COLLECTORS · THE MARKET STANDARD

Built for dashboards: sampling under load, per-second throttles, retention tiers. By design, a percentage of the truth.

Head-based sampling · Rate limits · Retention tiers
ARANTHOS CONNECT · THE RECEIVE ENDPOINT

Built for evidence: lossless, unsampled. Every event, in order, or a signed gap.

Sampling is how dashboards scale · A record cannot sample
THE BENCH TEST · SAME TRAFFIC · A COLLECTOR AND A RECEIVER 00:00:00.000000 UTC
billing_reconciliation claims_router dispatch_planner kyc_screening settlement_engine
EMITTED 1,204
A · A SAMPLING COLLECTOR · THE MARKET PATTERN SAMPLER · 2 OF 3 · RATE LIMIT
THE SAMPLED RECORD
66%
OF THIS TRAFFIC · AS SAMPLED
KEPT 790 · DROPPED 402
B · ARANTHOS CONNECT · THE RECEIVE ENDPOINT READ-ONLY GRANT · LOSSLESS
THE SEALED RECORD · ARANTHOS
100%
ONE TO ONE · OR A SIGNED GAP
KEPT 1,192 · DROPPED 0
SIGNED GAP · ON THE RECORD
A NEUTRAL WITNESS · NOT THE BUILDER, NOT THE OPERATOR
Plate 02 · The bench test, illustrative: same traffic, a sampling collector against Aranthos Connect, via OpenTelemetry

Tapped downstream, the record is lossless from the moment we receive. Tapped at the source, it is full fidelity from the first emitted event.

A receive endpoint. Never an installed component.

No sampling · Nothing silently dropped · At any limit, a signed gap
The fidelity is decided where the tap sits, not by what runs.
§4 · Prove · The instrument

In the record, or a signed gap. There is no third state.

Plate 03 · The recording strip, live
Plate 03 · The recording strip, live
§4 · PROVE · The hostile reader

The record answers hostile questions.

The day it matters, the reader is looking for the flaw. The record already holds the answers.

THE SEALED REGISTER · 14 DAYS · billing_reconciliation NOTHING CHOSEN · NOTHING SILENT · NOTHING QUIETLY CHANGED
01 QUIET
02 QUIET
03 QUIET
04 QUIET
05 QUIET
06 DEPARTURE
07 QUIET
08 QUIET
09 GAP · 41S
10 QUIET
11 QUIET
12 QUIET
13 QUIET
14 QUIET

Every interval is on the record: the quiet days, the departure, and the gap itself. Nothing was sampled out, nothing chosen by anyone.

14 / 14 ACCOUNTED
ASK THE RECORDFOUR QUESTIONS, IN TURN
VERIFIABLE WITHOUT ARANTHOS · PUBLIC KEYS · DOCUMENTED FORMAT · OPEN VERIFICATION PATH
Plate 04 · The hostile reader: four questions, answered by the record itself
EXHIBIT · EVIDENCE PACKET (EVP)

One sealed file. The whole record.

One object: a single sealed file carrying the record, the measurements, and the seals that bind them. It leaves the room.

RECORD

Every event received in the covered window. Nothing sampled, nothing silently dropped.

MEASUREMENTS

Every DHI reading, decomposable into the observable elements behind it.

GAPS

A signed gap record where a source went dark. Bounded, start to end, and signed.

SEALS

A content signature and an independent timestamp. Three clocks, never merged: declared, received, attested.

ACCESS

Opens with the file alone. Verifies without Aranthos.

The proof does not depend on our survival.
§4 · PROVE · The verification

Verify an Evidence Packet (.EVP)

Verify-report
THREE SEALED PACKETS · CLICK ONE TO CHECK
EVPbilling_reconciliation · EVP-7K44-2M · 318 BYTES
EVPbilling_reconciliation · EVP-7K42-9X · 332 BYTES
EVPbilling_reconciliation · EVP-7K43-6T · 336 BYTES
SHA-256 {{ digestDisplay }}{{ digestDisplay }}fcea 9d0a 394d 66d5 28b7 fefa ef00 69cd 6298 385d ef3b 4103 38de 6cb8 fc01 f798
FOUR CHECKS · SEAL · SIGNATURE · TIMESTAMP · DHI · AWAITING RUN
SEAL INTACT
SEAL BROKEN · CONTENT DOES NOT MATCH SIGNATURE
SIGNATURE VERIFIED
TIMESTAMP VERIFIED
DHI RECOMPUTED FROM THE RECORD · 90 · SAME INPUTS, SAME RESULT
DHI RECOMPUTED FROM THE RECORD · 27 · SAME INPUTS, SAME RESULT
SIGNED GAP VERIFIED · BOUNDED · 14:11:02Z TO 14:12:39Z
Valid.NO ACCOUNT NEEDED
billing_reconciliation · DHI 90 · WITHIN BASELINE · SEALED 2026-07-08 14:31:07Z
billing_reconciliation · DHI 27 · DEPARTURE · SEALED 2026-07-08 14:02:11Z · OUTSIDE LEARNED BASELINE
billing_reconciliation · SIGNAL LOST · SIGNED GAP · 14:11:02Z TO 14:12:39Z
Invalid.TAMPER EVIDENT · NO ACCOUNT
THE CHECK RUNS ON THIS DEVICE, ON ITS OWN · READ ONLY
Plate 05 · Verify-report
INDEPENDENTLY TIMESTAMPED · NOT ARANTHOS, NOT THE DEPLOYER

The timestamp comes from an independent time-stamping authority. Under eIDAS, an electronic timestamp cannot be denied legal effect or admissibility solely because it is electronic or not qualified.

The founding case.

The first case this instrument sealed is an early decision holding a company answerable for its autonomous system's behavior: measured against a learned baseline, signed, independently timestamped, and verified by a third party without an account.

Moffatt v. Air Canada (2024)
§5 · Independent and untouchable

Not the vendor. Not the host. Not the deployer.

100% math · Zero AI in the measurement loop · Same inputs, same result
The call

The team decides.

It hands the team the finding, then stops
No control

It cannot act on the system.

No kill switch · No repair · No rollback
Independent

Read-only by construction.

External · Separate · No hands on the target

Whoever keeps the record has an interest in what it shows. Here a third party keeps it, and cannot touch what it measures.

No SDK. No installed collector. No write path. The instrument cannot touch the system it measures.
Integrity

Integrity risk is removed by construction: the write path does not exist, verified in the code.

Confidentiality

Confidentiality is handled by controls: EU-hosted, encrypted in transit and at rest, read-only scoped credentials, auditable and revocable.

Nothing to install. Off the inference path: the instrument reads a copy and never sits between the system and its output.
Who it's for

Built for the people who sign the risk register.

CISO, CTO, AI-platform and risk teams operating autonomous systems in production:

BANKING INSURANCE HEALTHCARE INFRASTRUCTURE

Why now

The management body bears the ultimate responsibility for this risk. The record is how it shows oversight actually happened.

JANUARY 2025

Operational-resilience rules are live law.

TODAY

No law requires an independent record today. Liability already rewards one.

DECEMBER 2026

From December 2026, under the new Product Liability Directive, a court can order disclosure of evidence and, where a defendant fails to comply with that order, presume the product defective. The presumption is rebuttable.

A record starts to matter the day it starts recording.

On a high-risk system, the question is never whether it will drift. It is whether it was being measured when it did.

Access · Limited

Access is limited to a small number of design partner organizations.

Request access or write directly to fabien@aranthos.com Copied