Answer a driver in one short turn while the vehicle is moving, or hand off — with faults, safety and drive-away answers withheld, and anything reaching a vehicle function authorised by a person.
Take the spoken request as the cabin heard it, with the noise and the road speed behind it.
02
Read the state the request needs — motion, gear, which seat spoke and who else is in the car.
Reason
03
Resolve the request against the vehicle's own manual, its cabin functions and the trip under way.
04
Score how sure it is of the words themselves, separately from how sure it is of the intent.
05
Size the answer against the turn budget — what can be said now, and what needs the car stopped.
Decide
06
Hold anything that names a fault, clears a car to drive, or tells a driver what to do at the wheel.
07
Route a vehicle function, a private message or an emergency to the person or service that owns it.
Out
08
Speak one short answer, or say plainly that it is stopping and who takes it from here.
09
Retain what was asked, what was answered, what was withheld and how long the exchange ran.
→Product statement
The agent speaks and requests. A vehicle function, a safety answer and an emergency belong to a named person or an existing service, and the driver is told which.
Example workflow
One spoken request, end to end
AgentHuman
1Request heardWake word or a wheel-mounted press, with the speech, the noise and the seat it came from
2Cabin state readMotion, gear, road speed, who else is in the car and which profile is signed in, before anything is resolved
3Request resolvedThe words as recognised, the intent as scored, and the manual entry or cabin function it maps to
4Turn budget appliedHow long the answer takes to say, how many turns it would need, and whether the vehicle is moving
No human action required
Stages 1 to 4 run inside the cabin without a person in the loop — the hearing, the state read, the resolution and the turn budget all finish before anyone is called, and nothing has reached a vehicle function at the end of them.
5DecisionSplits on recognition confidence, on the turn budget and on whether anything would reach a vehicle function
Short, confident, nothing reaches the car
Spoken as one answer.
Unclear, long, or the car is involved
Handed over, and the driver is told.
Connected-services agent or roadside
Picks up with the request as heard, the state the car was in and what the assistant held back, decides what the driver is told, and authorises anything that reaches a vehicle function under their own name.
Take over · Correct · Escalate to roadside
Handled — logged back▼
6Answer spoken and filedSaid once in the cabin and written to the session record; no command, setting or drive-mode change is sent from here
7Outcome evaluatedWhat was asked, what was answered, what was handed off, how long it ran and whether the driver asked again
Handoffs
Every exchange the assistant stopped early is counted in the evaluation.
What should not run autonomously
Human approval stays in control
Outside the boundary — human approval required8 items
Any command that reaches a vehicle function.
Clearing a vehicle as safe to keep driving.
Naming a fault behind a warning light.
Telling a driver what to do at the wheel.
Automation boundaryAgent acts unaided
✓Answer cabin and manual questions from the vehicle's own documentation.
✓Keep the answer inside the turn budget while the car is moving.
✓Score its own recognition and stop rather than guess again.
✓Name who takes over, and say so out loud before it stops.
The assistant speaks, it does not act. A vehicle function needs pre-conditions, a named authoriser and a stop.
Reading a private message aloud to the cabin.
Retaining a voiceprint or enrolling a speaker.
Handling a crash or a medical call alone.
Buying, subscribing or paying from the cabin.
Example output
One spoken request, annotated
Everything the assistant says is attached to what the cabin heard and the state the car was in.
Assistant output · one request at road speedIllustrative example
Driver asked
Cabin state
Recognised
Spoken back
Confidence
What has failed
What is this light on the dash?
Moving, two occupants
Above threshold
The manual's own wording
86%
Not the assistant's to say
As receivedThe driver's words as the cabin heard them, beside the state the car was in — nothing on this side is inferred.
Evidence usedOwner's manual entryCluster message as shownRoad speed and gear
Why the lamp is not diagnosedThe manual describes the lamp. What has actually failed is a technician's call.
ActionTake overCorrectEscalate to roadside
What the score decidesBelow the threshold it stops and names who takes over, not who to ask again.
Value
Where AI adds value
The same four claims, placed at the point in the workflow where each one applies.
Where the value landsValue 01 – 04
Every spoken request in the cabinWake word or a wheel-mounted press
03Hear & answer
Answer inside the driver's attention
Resolve the request against the vehicle's own manual and cabin functions, then size the answer to what can be said while the car is moving.
01Approved path
Keep the routine question to one turn
A manual question, a cabin setting or a trip question is answered once — without a menu, a screen or a second attempt at road speed.
02Human review
Stop early and name who takes over
A fault, a safety question, an emergency or anything reaching a vehicle function leaves the cabin for the person who owns it, and the driver hears that it has.
04Build an evidence trail
Retain the request as heard, the state the car was in, what was said, what was withheld, how long it ran and who took over — on both paths.
Integrations
Typical integrations
Five system groups connect to the same agent. Which of them are in scope is decided in discovery.
Head unit & cabinWake-word engine · microphones Speech recognition · text-to-speech
Vehicle state & contentMotion and gear · occupancy Owner's manual · cluster messages
Integration availability depends on the client's existing systems and API access.
Agent controls
Six layers between the model and the driver
Each control wraps the one inside it. An answer clears every layer before it is spoken, and the vehicle function itself sits outside all six.
L6 · Outermost — last line of defenceInward → L1 · closest to the model
L6Rollback / safe modeReturn the cabin to its built-in commands if evaluations or production signals degrade.Roll back
L5Voice data and recordCapture window, who can hear the reply, how long voice is kept and what the trail holds.Limit
L4Function pre-conditionsA request that would reach a vehicle function carries its pre-conditions, authoriser and stop.Gate
L3Turn budgetThe answer is sized to what can be said while the vehicle is moving.Bound
L2Cause and safety blockA named fault, a safe-to-drive answer and driving advice are kept out of the reply.Withhold
L1Recognition gateRecognition is scored, and a phrase under the threshold ends the exchange.Stop
Model coreAnswer drafted — the request as recognised, the intent as scored, the source it came from and confidence
L1 – L2Decide whether the assistant speaks at all
L3Keeps the exchange short while the car moves
L4 – L5Leave the function with a person, cabin data bounded
L6Pulls automation back when signals degrade
How Nestack evaluates it
Evaluate the whole exchange — not only the sentence the driver hears.
Coverage runs the whole depth of the workflow, and every layer is cut by slice.
Surface — the answer spoken in the cabin
Depth of coverage ▼
E1Final-output evaluationWas the spoken answer true to the vehicle's own documentation?
E2Step-level evaluationDid it recognise the words, and separately, the intent?
E3Tool evaluationDid it read the right vehicle state, seat and manual entry?
E4Refusal recallDid a fault, a safety answer or driving advice get spoken?
E5Slice evaluationHow does the exchange change across speakers and driving conditions?
E6Business outcomeHow long was the driver occupied, and how often did they repeat?
Floor — how long the driver was occupied
Failure modes
Where each failure originates in the agent
Seven failure modes plotted against the five stages of the agent lifecycle. None of them commands a vehicle — the recognition gate, the turn budget and the named authoriser are the controls that stop them.
Agent lifecycleDirection of processing →
01 · Capture2 modes
IV-01
Passenger heard as the driver
A back-seat remark is taken as the driver's request.
IV-02
Message spoken to a full cabin
A private reply is read out in front of passengers.
Stage hearsThe wake, the phrase, the noise and who is aboard
02 · Recognition2 modes
IV-03
Accent falls out of coverage
The same phrase works for some drivers and not others.
IV-04
Third attempt at road speed
The exchange keeps going instead of handing off.
Stage resolvesThe words, then the intent, each scored on its own
03 · Answer1 mode
IV-05
Warning light answered as a fault
A lamp is given a cause the vehicle never sent.
Stage speaksOne short reply, or the handoff and who now owns it
04 · Handoff / request1 mode
IV-06
Emergency handled as a query
A crash or medical call is answered, not passed on.
Stage requestsThe vehicle function a person authorises and stops
05 · Change / Version1 mode
IV-07
Manual revision not carried
The cabin answers from a superseded manual edition.
Stage tracksModel, prompt, manual and vehicle-software changes
Sev-1 · the exchange becomes the hazardSev-2 · the wrong thing is said, or heardSev-3 · the answer thins and hands off sooner
A driver the recogniser was not built around, a cabin at motorway speed and a passenger talking across the request are where the assistant asks again instead of answering. Nestack reports performance by slice, not only in total.
Slice performance — reported separately, not only in aggregateIllustrative example
Slice
Failure rate
Lift
Lift vs. threshold
Status
Non-majority accents and languages
5.8%
3.3×
Review
Speech at motorway speed
4.0%
2.3×
Review
Passengers speaking over the driver
3.2%
1.8×
Watch
Routine media and navigation
1.2%
0.7×
Normal
Bar: repeated-turn rate lift vs. routine-request baseline · scale 0–4.0× · tick at 2.0×2 of 4 slices over threshold
Evidence-linked improvement
A turn the driver had to repeat is the signal
An exchange that ran to a second attempt is not closed when the driver gives up on it. It moves the recognition threshold, the turn budget or the wording.
Improvement cycle · five stagesSwitchback — the path turns at Improve and returns at Learn
01Detect
Repeated turns, early handoffs or long exchanges move in a cohort.
02Diagnose
The cause sits in capture, in recognition, in the wording, in the turn budget, or in the vehicle's own software.
03Improve
The threshold or the wording changes under your in-vehicle change control, with a named approver.
04Verify
Re-run on stored cabin audio from that cohort, including the exchanges the driver abandoned.
05Learn
The abandoned exchange joins the regression set and the limit it exposed enters the handoff rules.
Learn → DetectThe return edge. A change to what the assistant may say while a vehicle is moving is signed off before it ships, not after a driver has heard it.
Typical build scope
Twelve workstreams across six weeks
The build scope read against the delivery timeline. Week structure follows the six-week plan — discovery, capture and recognition, answers and handoff, evaluation, integration, then supervised driving and handover.
WorkstreamWeek 1Week 2Week 3Week 4Week 5Week 6
01In-cabin discovery and automation boundary.
02Rules for what the cabin may never say.
03Wake, capture window and retention limits.
04Speaker and occupancy handling in the cabin.
05Recognition scoring and turn-budget limits.
06Vehicle manual and cluster-message mapping.
07Handoff routing and emergency escalation.
08Vehicle-function gating and authorisers.
09Accent, noise and road-speed test sets.
10Evaluation suite, slices and audio replay.
11Session record, consent and audit logging.
12Head-unit deployment and Agent Care handover.
12 workstreams · 6 weeks · bar shows the weeks a workstream is active — several run in parallelFinal scope and sequence confirmed in discovery
Engagement tiers
What each tier includes
Rows are the capabilities named in each tier's scope. Higher tiers include everything below them.
Capability✓ in scope · — not at this tierPilotOne vehicle line, one languageProductionLive in-cabin assistantAdvancedMulti-brand / multi-language
Introduced at Pilot
Cabin and manual questions in one turn✓✓✓
Fault, safety and driving answers withheld✓✓✓
Turn budget enforced while moving✓✓✓
Capture window and voice-retention limits✓✓✓
Vehicle functions authorised by a person✓✓✓
Handoff named aloud, routed to desk or roadside✓✓✓
Baseline evaluation✓✓✓
Introduced at Production
Session write-back and driver profiles—✓✓
Cabin usage and turn-length reporting—✓✓
Observability and evaluation—✓✓
Introduced at Advanced
Multi-language and multi-brand controls——✓
Build priceFrom $5,000From $8,000Custom quote
Final build priceConfirmed after discovery based on vehicle lines and languages in scope, head-unit and cloud integration, the vehicle functions in reach, handoff routing and deployment requirements.
Separate from buildBuild pricing is separate from recurring Agent Care, which covers managed monitoring, evaluations, incidents and verified improvements after launch.
What we need from you
What you bring, and what we build with it
Each input maps to a piece of build scope and a week in the delivery timeline.
You bringWe build with it
01Your in-cabin scripts and what an answer may never claim→Rules for what the cabin may never sayWeek 1
02Your wake word, capture window and voice-retention policy→Wake, capture window and retention limitsWeek 1
03The owner's manual and cluster-message set for the lines in scope→Vehicle manual and cluster-message mappingWeek 3
04Where a driver should be handed off, and to whom→Handoff routing and emergency escalationWeek 3
05Which vehicle functions may be reached, and what stops one→Vehicle-function gating and authorisersWeek 4
06Cabin recordings across your drivers, languages and road speeds→Accent, noise and road-speed test sets, and failure-mode testingWeek 4
07Named desk agents, a roadside contact and a supervisor→Session record and desk handoff, then supervised drivingWeeks 5–6
Nothing else is requiredDeployment, documentation and Agent Care handover are ours.
Delivery timeline
Four phases across six weeks
Phases are drawn over the weeks they actually occupy. Week 5 carries both the replayed cabin audio and the first vehicles running the assistant live.
PhaseW1W2W3W4W5W6
DiscoveryW1
BuildW2 – W3
EvaluateW4 – W5
Pilot & LaunchW5 – W6
Week focusW1Boundaries, capture limits and what the cabin may never sayW2Speaker handling, recognition scoring and the turn budgetW3Manual and cluster mapping, and where a driver is handed offW4Evaluation suite, road-speed and accent test sets, function gatingW5Session record, slice testing and the first supervised vehiclesW6Your drivers use it on the road, then Agent Care starts
Reading the bandFunction gating is built in week 4, before anything the assistant raises reaches a vehicle in week 5.
At the end of W6The assistant has run in moving vehicles with a turn budget on every exchange, fault and safety answers held back, and every function authorised by a person.
DurationSix-week plan shown · typical delivery 4–6 weeks depending on scope confirmed in discovery.
Next step · Automotive AI agent
Build an in-car voice assistant around the driver's attention.
Show us a week of cabin recordings — the requests, the repeats and the ones the driver gave up on — with the vehicle state behind them. We'll answer them inside a turn budget and mark every exchange that ran too long, said too much, or should have left the cabin.
