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Real Estate AI agent · Property tax

Property-Tax Appeal Evidence AI Agent

Scope the parcels, rebuild each jurisdiction's non-extendable deadline from this year's source, and assemble the exhibits the form demands — never an opinion of value, which a named person states under oath.

Typical delivery
4–6 weeks
Deployment
Your stack
A person signs
Pre-filing
After launch
Agent Care

What this agent does

Assembles the record, not the number on it

In

  1. 01

    A notice of value lands, and the parcels it covers are scoped to the roll and the jurisdiction they sit in.

  2. 02

    A deadline falls, and it is rebuilt from that year's published source rather than read from a cached table.

Reason

  1. 03

    A California parcel is read against the current Board of Equalization letter, not last year's county list.

  2. 04

    A Texas notice arrives, and the 30-day clock at Tex. Tax Code §41.44 runs beside the 15 May date.

  3. 05

    A parcel's income and expenses are built on the accounting basis the form requires, for the period it requires.

Decide

  1. 06

    A parcel's signer is checked against the jurisdiction's eligibility rule and the authorisation on file.

  2. 07

    A parcel's comparable set is assembled with its provenance — the opinion of value stays with a named person.

Out

  1. 08

    A parcel is decided, and the escalation calendar opens that day, shorter than the filing calendar behind it.

  2. 09

    Execute write actions only inside the approval boundaries agreed during implementation.

Product statement

The agent assembles the record; a named person signs — in California under penalty of perjury, and states the opinion of value the agent never forms.

Example workflow

One parcel, notice to signature

  1. 1Notice of value receivedAssessment roll, notice of value, prior determination or portfolio intake
  2. 2Record assembledIncome and expense lines, comparables and provenance, authorisations, each with its source
  3. 3Package proposedExhibit set, open gaps, deadline and confidence
  4. 4Controls appliedJurisdiction deadline checks, signer-eligibility tests, cross-filing reconciliation and confidence threshold

No human action required

Stages 1 to 4 run unaided, and nothing is signed or lodged at any of them — the agent is assembling, and the signer lane opens at the confidence gate.

5DecisionTurns at the confidence threshold
High confidence

Goes to the named signer to review.

Low confidence

Adds a tax-counsel read first.

Signer review

The package is held with its exhibits, its open gaps and the confidence.

Approve · Amend · Send to counsel review

Approved — released for signature

  1. 6Appeal systems updatedOnly where write access and approval policy allow it
  2. 7Outcome evaluatedExhibit completeness, on-time filing, dismissals and post-filing amendments

Amendments

Each amendment made in review is counted in the evaluation.

What should not run autonomously

Human approval stays in control

Outside the boundary — human approval required

8 items

  • Forming or implying an opinion of value.
    • Submitting the application to the authority.
    • Signing or swearing to the application.
    • Appearing before the notary or the board.

  • Automation boundary

    Agent acts unaided

    • ✓Assemble the exhibit set that the jurisdiction form actually demands.
    • ✓Rebuild each deadline from that year's published source.
    • ✓Reconcile the income lines to the books and to prior filings made.
    • ✓Flag the gap the signer must close, and hold the package.

    Writes land inside the boundaries agreed at implementation, never ahead of a human signature.

    • Making legal argument on the parcel.
    • Certifying the accounts as an independent CPA.
    • Agreeing to extend a California hearing date.
  • Changes to deadline, signer or exhibit rules.

Example output

One parcel package, annotated

Everything the agent assembles stays attached to the record it came from, and stays after the filing.

Appeal-record output · single parcel

Illustrative example
Parcel
Alameda County parcel
Assembled line
Comparable set and provenance assembled, opinion-of-value box left blank
Filing deadline
15 September 2026
Deadline source
BOE LTA 2026/023
Confidence
91%
Signer of record
Owner officer, under penalty of perjury

As received

Taken from the assessment roll and the county's published dates — nothing on this side is written by the agent.

Evidence cited

  • Recorded sales records
  • Operating statement
  • Prior board determination

Why the box is blank

Sworn under penalty of perjury by a named person, and it is logged.

What the score decides

Below the configured threshold the package picks up a tax-counsel read before.

Action

ApproveAmendSend to counsel review

Value

Where AI adds value

The same four claims, placed at the point in the workflow where each one applies.

Where the value lands

Value 01 – 04

Every parcel

From the assessment roll

03Assembly

Build from the roll and the form

Ask what the jurisdiction's form actually demands, not what last year's package happened to contain.

01Approved path

The deadline does not move

Routine parcels arrive with their exhibits assembled and their deadline dated.

02Human review

Send review where the year can be lost

Open gaps and contested signers come first — in New Jersey an unanswered Chapter 91 request bars the appeal.

04

Build an evidence trail

The parcel, the exhibit behind it and the signer who filed stay on the application.

Integrations

Typical integrations

Five system groups connect to the same agent. Which of them are in scope is decided in discovery.

  • Assessment and roll data

    • County assessor rolls
    • Public parcel and sales data

  • Property accounting

    • Yardi Voyager
    • MRI
    • RealPage
    • Entrata

  • Appeal and tax systems

    • itamlink
    • PTMS
    • OneSource Property Tax

Agent

Property-tax appeal evidence

  • Reads the roll
  • Assembles the record
  • Holds for signature

  • Documents and authorisations

    • Powers of attorney
    • forms
    • SharePoint
    • document stores

  • Observability & evaluation

    • OpenTelemetry
    • Langfuse
    • Supported monitoring/evaluation sources

Integration availability depends on the client's existing systems and API access.

Agent controls

Six layers between the model and the application

Six rings, outermost first. Whatever clears the innermost is named in the map beneath this.

L6 · Outermost — last line of defence

Inward → L1 · closest to the model

L6Rollback / safe modePull assembly back to exhibit-only when evaluation or production signals degrade.Roll back
L5Version monitoringTrack model, prompt, deadline-source and form-edition changes.Track
L4TraceabilityRecord the exhibits cited, the gaps, the amendments and the signature time.Record
L3Signer reviewHold packages for the named signer; it governs release, not whether a signed application is right.Gate
L2Policy guardrailsTest packages against jurisdiction deadlines, signer rules and exhibit lists; a failure returns the package.Restrict
L1Confidence thresholdsRoute low-confidence packages to a tax-counsel read before the signer sees them.Require review
Model corePackage assembled — exhibit set, open gaps, deadline and confidence
L1 – L2
Test whether a package may stand
L3
Puts the signature in a person's hands
L4 – L5
Keep the parcel and the exhibit behind it
L6
Reverts to exhibit assembly when signals degrade

How Nestack evaluates it

Evaluate the whole appeal season — not only the finished application.

Coverage runs the whole depth of the workflow, and every layer is cut by slice.

Surface — the application the board reads

  1. E1Final-output evaluationDid each assembled line trace to a document in the file?
  2. E2Step-level evaluationDid the agent use the right jurisdiction, form edition and deadline source?
  3. E3Tool evaluationDid it read and write the correct parcel and the correct roll year?
  4. E4Confidence calibrationDo low-confidence packages actually attract more signer amendments?
  5. E5Slice evaluationHow does performance change across specific authorities and parcel types?
  6. E6Business outcomeHow many packages needed an amendment, or a correction after the application went in?

Floor — the outcome the owner answers for

Failure modes

Where each failure originates in the agent

Seven failure modes, set at the stage where each one first begins.

Agent lifecycle

Direction of processing →

  1. 01 · Retrieval

    1 mode

    • FK-03

      Cached deadline table

      Deadline read from last year's county list.

    Stage gathers

    Rolls, notices, published dates and authorisations

  2. 02 · Reasoning

    2 modes

    • FK-04

      Implied value opinion

      A comparable set is arranged so it reads as a recommendation.

    • FK-06

      Wrong accounting basis

      Income reported on a basis the return does not use.

    Stage proposes

    Exhibit set, open gaps, deadline and confidence

  3. 03 · Tool / write

    2 modes

    • FK-02

      Ineligible signer

      Package built for a signer the forum rejects.

    • FK-05

      Cross-filing mismatch

      Appeal and RPIE income differ on the same parcel.

    Stage writes

    Only where write access and approval policy allow it

  4. 04 · Output

    1 mode

    • FK-01

      Incomplete exhibit set

      A required schedule or attachment is missing.

    Stage returns

    The application the signer swears and files

  5. 05 · Change / Version

    1 mode

    • FK-07

      Silent deadline drift

      A published date changes and the calendar keeps the old one.

    Stage tracks

    Model, prompt, deadline sources and form editions

  • Sev-1 · a package leaves the boundary
  • Sev-2 · a wrong line reaches the application
  • Sev-3 · date source changes, package to review
See the complete Real Estate failure-mode catalogue

Affected slices

One taxing authority can carry the exposure

A portfolio-wide on-time filing figure can read well while one taxing authority or parcel type carries most of the incomplete sets. Nestack reports exhibit completeness by slice, not only in total.

Slice performance — reported separately, not only in aggregate

Illustrative example
SliceFailure rateLiftLift vs. thresholdStatus
Newly reassessed parcels9.2%3.7×Review
Multi-authority portfolios6.7%2.7×Review
Vacant or partly let parcels4.3%1.7×Watch
Stable let parcels1.4%0.6×Normal

Bar: gap-rate lift vs. stable-parcel baseline · scale 0–4.0× · tick marks the 2.0× review threshold

2 of 4 slices over threshold

Evidence-linked improvement

Every season ends by adding a case

A cycle is done when the missed deadline has become a case the next release must pass. That suite is what the next season filed is measured against.

Improvement cycle · five stages

Switchback — the path turns at Improve and returns at Learn

  1. 01

    Detect

    Exhibit completeness falls in a taxing-authority slice.

  2. 02

    Diagnose

    The parcel that was over-assessed for a year nobody appealed is read back until the cause narrows to one.

  3. 03

    Improve

    Stamp the change; the parcels behind it are filed against that number.

  4. 04

    Verify

    Each touched parcel case is run again, and one red stops the release.

  5. 05

    Learn

    It stays a standing test, and the deadline rules move with it.

  6. Learn → Detect

    The return edge. Next season detection runs against a suite one case longer.

Typical build scope

Twelve workstreams across six weeks

The build scope read against the delivery timeline. Week structure follows the six-week plan — discovery, sources, appeal workflow, evaluation, integration, then production validation and handover.

Workstream

Week 1Week 2Week 3Week 4Week 5Week 6

  1. 01Appeal workflow discovery and boundary definition.Week 1
  2. 02Roll and accounting source assessment.Week 1, Week 2
  3. 03Jurisdiction deadline, form and signer mapping across markets.Week 1, Week 2
  4. 04Parcel and roll ingestion, normalisation.Week 2
  5. 05Exhibit assembly and source binding.Week 2, Week 3
  6. 06Confidence scoring and gap routing.Week 3
  7. 07Signer review workflow.Week 3, Week 4
  8. 08Assessment and tax-system integration.Week 5
  9. 09Deadline and exhibit cases.Week 4, Week 5
  10. 10Guardrails and signing controls.Week 4
  11. 11Parcel-trail instrumentation.Week 5, Week 6
  12. 12Deployment, documentation and Agent Care handover.Week 6

12 workstreams · 6 weeks · bar shows the weeks a workstream is active — several run in parallel

Final 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 authority, one portfolioProductionProduction tax systemsAdvancedMultiple states / authorities
Introduced at Pilot
Assembly to your rolls and forms✓✓✓
Signer review hold✓✓✓
Exhibit-completeness baseline✓✓✓
Introduced at Production
Reporting by taxing authority—✓✓
Review workflow in your systems—✓✓
Approved write-back—✓✓
Assessment-data integration—✓✓
Introduced at Advanced
Multi-authority rule sets——✓
Multi-stage signer reviews——✓
High parcel counts——✓
Multi-jurisdiction filing controls——✓
Build priceFrom $5,000From $8,000Custom quote
Final build price
Confirmed after discovery based on integrations, workflow complexity, transaction volume, approval controls and deployment requirements.
Separate from build
Build 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.

  1. 01Your parcel list and roll identifiers

    Parcel and roll ingestion and evidence mapping

    Week 1

  2. 02Representative filed applications

    Assembly baseline, source binding and gap detection

    Week 2

  3. 03Your jurisdictions and signing conventions

    Jurisdiction deadline, form and signer mapping

    Week 1

  4. 04Access to relevant APIs, feeds or exports

    Roll and accounting source assessment, then integration setup

    Week 2

  5. 05Applications you would not want dismissed

    Deadline cases and the evaluation suite

    Week 4

  6. 06What no signed application may guess

    Confidence scoring, gap routing, guardrails and signing controls

    Week 3

  7. 07Named signers to review packages

    Signer review workflow, then pilot and production validation

    Weeks 5–6

Nothing else is required

Deployment, documentation and Agent Care handover are ours.

Delivery timeline

Four phases across six weeks

Each phase is as wide as the weeks it consumes, so the doubling at week five is work, not layout.

Phase

W1

W2

W3

W4

W5

W6

  1. DiscoveryW1
  2. BuildW2 – W3
  3. EvaluateW4 – W5
  4. Pilot & LaunchW5 – W6

Week focus

W1Appeal workflow discovery, rule mapping and the automation boundary

W2Source integration and the assembly baseline

W3Package workflow, confidence logic and signing controls

W4Evaluation suite, deadline checks and failure-mode testing

W5Tax-system integration, pilot parcels and targeted corrections

W6One appeal season run under the tax director, then Agent Care handover

Reading the band
A bar sits only on the weeks its work is named in. The week 5 overlap is real work, not padding.
At the end of W6
When the season validates, Agent Care takes the agent on.
Duration
Six-week plan shown · typical delivery 4–6 weeks depending on scope confirmed in discovery.

Next step · Real Estate AI agent

Build an appeal-record agent around the person who signs.

Show us your parcels, your jurisdictions and who signs. Bring one taxing authority and one filing season, and we will map the assembly workflow, rebuild that season's deadlines from the published source, and name what stays with a person — starting with the opinion of value, which in California is stated on the face of the application under penalty of perjury and, if the county board does not hear the application within two years, becomes the value taxed under Revenue and Taxation Code §1604(c).

Typical delivery
4–6 weeks
Deployment
Your parcels and rolls
A person signs
Pre-filing
After launch
Agent Care available

Nestack Agents · Property-tax appeal evidence

AGT-RE-18 · Agent Care available after launch

Build an appeal-record agent

Four questions so the call starts from your actual setup — then pick a time that suits you.

About you
Your parcels

No obligation. We’ll map the workflow, name the automation boundary and tell you if an agent is the wrong answer.