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Abstract
Making a body of knowledge available to AI systems is commonly approached as
an infrastructure problem: ingestion pipelines, chunking, embeddings, a vector
store, a retrieval and reranking layer, an API surface, and the operational
work of keeping all of it running. These components solve real problems and
are the right answer in many deployments, particularly where privacy,
determinism, freshness guarantees,…
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Abstract
Making a body of knowledge available to AI systems is commonly approached as
an infrastructure problem: ingestion pipelines, chunking, embeddings, a vector
store, a retrieval and reranking layer, an API surface, and the operational
work of keeping all of it running. These components solve real problems and
are the right answer in many deployments, particularly where privacy,
determinism, freshness guarantees, access control, or latency are binding
requirements.
This paper describes a different allocation of the same work, and states what
it costs.
Multi-Platform Linked Public Building (MPLPB) moves a substantial portion of
the retrieval problem upstream into the information architecture of the corpus
itself. Documents are authored as complete artifacts carrying identity, scope,
status, version, provenance, relationships, and navigation. The public
implementation uses ordinary web primitives and ordinary public indexing. The
local implementation, Smart Local MPLPB, uses plain HTML and standard-library
Python with no network and no dependencies.
The claim is a comparability claim, not a ranking claim. For a defined class
of use â a bounded corpus that a stateless retrieval-capable system must be
able to find, orient within, and reconstruct accurately â a structure-first
corpus supplies the functional capabilities that an API-based retrieval stack
supplies for the same class: correct document identity,
current-versus-superseded status, declared scope, provenance that travels with
retrieved material, and relationship structure a reasoner can navigate. It
supplies them at consumer cost.
The public corpus described here was built under a declared constraint:
consumer hardware and consumer AI front ends only. No vector database, no
embedding pipeline, no paid API, no commercial SEO tooling, no author-operated
retrieval service. That constraint is the paperâs central evidentiary asset,
because it is auditable â any reader can check whether the corpus depends on
infrastructure the author is not disclosing.
What the demonstration measures is drift: how often the mechanics come back
recovered as written versus blended, inverted, or invented. Drift is
measurable without a control arm, and it is the quantity the frameworkâs own
falsifier is written against. What the demonstration does not settle is
whether the structure outperforms flat storage of the same files; that
ablation is specified, unrun, and named as such in §12.
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1. Introduction
Making information visible to machines is usually treated as a problem of
adding machinery.
A conventional path is familiar:
documents â ingestion â chunking â embeddings â vector store â retrieval /
reranking â model
Every component in that chain addresses a legitimate engineering problem.
Documents are messy. Relevant material is buried in long prose. Versions
conflict. Relationships are implicit. Query wording does not match document
wording. Retrieved fragments lose provenance. So the retrieval layer must
infer, reconstruct, rank, and package before a model can reason over anything.
There is a second place that work can be done.
Rather than increasing the sophistication of the machinery surrounding poorly
structured documents, increase the machine-legibility of the documents
themselves.
MPLPB takes this route. The corpus is not an undifferentiated pile of text
awaiting an intelligent indexer. It is a structured environment of complete
artifacts, each declaring what it is, what it covers, when it applies, whether
it is current, what it supersedes, and what it relates to.
The retrieval problem changes accordingly. The indexer is no longer solely
responsible for discovering the corpusâs conceptual architecture, because much
of that architecture has been published. The model is no longer solely
responsible for inferring whether a fragment is current, local, superseded, or
authoritative within scope, because those distinctions travel with the
artifact.
This paper examines the economic consequence, and states the claim in the form
that can be checked:
For a bounded corpus that must be discoverable and reconstructible by
arbitrary retrieval-capable systems, a structure-first architecture delivers
comparable functional capability to an API-based retrieval stack, at a cost
reachable by an individual or a small lab, under a declared
no-paid-infrastructure constraint.
The rest of the paper specifies what âcomparable functional capabilityâ
covers, what it excludes, what the constraint was, and what remains untested.
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2. Comparable Capability, Declared Scope
The unproductive version of this argument is a ranking argument â that
structure-first is better than RAG, or that RAG is better than
structure-first. Both formulations are unanswerable without a workload, and
both invite an evaluation the architecture was never built to win.
The productive version borrows the frameworkâs own precedence rule. Authority
is local to the question and decided by declared scope. Two systems can be
genuinely comparable across a defined capability set while differing entirely
outside it, and the honest move is to declare the set.
2.1 What both supply
For a bounded corpus that a stateless system must find, orient within, and
reconstruct:
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Capability API-based retrieval stack MPLPB
------------------------- ------------------------- ---------------------------------
Locate relevant material Embedding similarity plus Declared scope, trigger
for a query reranking conditions, and ordinary lexical
indexing
Identify what a retrieved Chunk metadata assigned Document ID and category declared
unit is at ingestion in the artifact
Distinguish current from Index freshness policy, status and supersedes fields,
superseded re-ingestion enforced by validator
Attach provenance to Source tracking through Provenance as fields of the hit
retrieved text the pipeline object, not a render-time
addition
Express relationships Knowledge graph or link Typed links and indexes authored
between units table built at ingestion in the corpus
Refuse rather than Confidence thresholds, answer_without_retrieval: false
confabulate guardrails in every shipped mode
Route between adjacent Namespace or collection Declared-scope precedence with an
domains filters explicit ambiguous return
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The capabilities are the same capabilities. The difference is where in the
pipeline they are produced, and therefore who pays for them.
2.2 What MPLPB does not supply
The following are properties of a private retrieval stack that the public
MPLPB implementation does not attempt to provide, and a corpus requiring any
of them should not use the public form:
- Privacy. Public MPLPB is public. This is not a limitation to be worked
around; it is the substrate. Private corpora use the local implementation,
which supplies structure without publication.
- Deterministic retrieval. Public search ranking varies by vendor, day,
region, and index state. A stack you operate does not.
- Freshness guarantees. Public indexing latency is outside the authorâs
control. Re-ingestion into a stack you own is not.
- Access control. The mplpb:protected flag filters retrieval; it is not
authentication. Smart Local MPLPB states this explicitly and declines to
implement an inference-based gate, on the grounds that dressing a stated
caveat as a mechanism is worse than the caveat.
- Low-latency retrieval over large specialized datasets. Not attempted, not
claimed.
Naming these is not a concession. It is the same discipline the framework
applies to documents, applied to itself: a system that declares its scope can
be routed to correctly, and a system that does not will eventually answer a
question it had no business answering.
2.3 On protocol-based context delivery
Model Context Protocol and similar interfaces are frequently raised as the
alternative, and the comparison is a category error worth naming rather than
arguing.
MCP is a transport and interface layer: a standard way for a model to reach a
data source or tool. MPLPB is a corpus layer: how the material on the other
end is organized so that whatever reaches it can use it. They occupy different
positions in the same stack and compose cleanly. A well-formed MPLPB corpus is
a good thing to expose over MCP, and exposing a badly structured corpus over
MCP does not make it better structured.
The relevant observation is that a corpus authored this way is reachable by
whatever arrives: a search-capable assistant, an enterprise search system, a
conventional search engine followed by a model, a local application, or a
protocol client. The corpus does not need to know which. That is the
portability property, and it is the reason the persistence layer is
deliberately uninteresting technology.
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3. The Constraint
The public MPLPB corpus was built under a rule set before the work began, and
maintained since:
1. Consumer hardware only. No server, no rented compute, no self-hosted
service.
2. Consumer AI front ends only. The retrieval and reasoning layer is whatever
a member of the public can open in a browser or app. No API keys, no
programmatic access, no fine-tuning, no paid model tiers used as
infrastructure.
3. No retrieval infrastructure operated by the author. No vector database, no
embedding pipeline, no ingestion service, no hosted RAG.
4. No commercial visibility tooling. No SEO service, no paid placement, no
metadata consultancy, no backlink purchasing.
5. Ordinary publication surfaces only. Public platforms available to anyone,
using their default features.
This constraint is the paperâs principal evidentiary asset, and it is worth
being precise about why.
An economic claim about a corpus is only as good as the disclosure of what
supports it. If recoverability turned out to rest on infrastructure the author
operates and did not mention, the claim would be hollow. The constraint makes
that auditable in the direction that matters: a reader can check whether the
corpus is reachable through ordinary public means, and can check whether
anything in the observed behaviour requires an explanation the constraint
forbids.
The residual costs are the ones the constraint permits: the authorâs time,
consumer devices already owned, and free-tier accounts on ordinary platforms.
The dominant term is authoring effort â the structural work described in §5 â
which is the point of the whole architecture.
Both reference implementations are published as public repositories under MIT
(code) and CC BY 4.0 (documentation). This matters for the constraint
specifically: a reader does not have to accept the disclosure on the authorâs
word. The local implementation can be cloned and run, and its dependency
surface inspected directly â Python 3.9 or newer, standard library only, no
package installation, no server, no database, no network call at any point in
execution. A claim about what infrastructure a system does not require is best
supported by a system that can be executed and found not to require it.
3.1 What the constraint does not eliminate
The public indexers are not free; they are simply not paid for by the author.
Google, Bing, and the assistants built on them represent enormous
infrastructure sitting outside the authorâs system boundary. MPLPB uses it
rather than reproducing it.
Two things follow, and both should be stated rather than glossed. First, the
economic result is a statement about the authorâs cost, not about total system
cost â the infrastructure exists and someone built it. Second, that
infrastructure is not under the authorâs control, which is precisely why §2.2
lists determinism and freshness as properties this form does not supply.
The local implementation exists in part to show that the principle does not
reduce to borrowed search. Smart Local MPLPB runs the same architecture over a
directory of plain HTML with an in-memory SQLite FTS5 index and a LIKE-based
fallback for interpreters built without FTS5, with no network at any point.
Public search is one indexer. FTS5 is another. A future engine is a third. The
corpus survives substitution of the reader, and that is the invariant the
constraint is testing.
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4. Drift as the Measurable Property
A comparability claim needs something measured, and the measurable quantity
here is not accuracy against a baseline â that requires the control arm
described in §12. It is drift.
Drift is what the frameworkâs falsifier is written against:
If independent observers using different search-capable systems consistently
fail to reconstruct the framework â surfacing the documents but blending,
inverting, or inventing the mechanics â then the artifacts are not carrying
the continuity, and the claim is falsified or the corpus requires repair.
Reconstruction outcomes fall into four categories: recovered as written,
blended (two mechanics merged into one), inverted (a rule reproduced
backwards), and invented (a mechanic attributed to the corpus that is not in
it). Drift is the rate of the last three.
Drift is measurable without a control arm because it is scored against the
source documents, which are fixed and public. It requires no comparison
system, no benchmark suite, and no infrastructure. It requires a query set, a
scorer, and a ledger.
The recorded state as of this writing, using the labels the source documents
use for themselves:
- Five author-run trials, 2026-07-11. Weak layer (recovery, surface
traceability) passed. One low-severity terminology drift logged:
Constraint-Based for constraint-first.
- One non-author run, 2026-07-26, on an independent apparatus. Weak and
strong layers passed across four mechanics probes: the separation rule,
domain precedence, the header block, and the safety override. Longitudinal
criterion partial. No inversions, no inventions.
- One partial adversarial reconstruction, 2026-07-07, with two negative
findings retained: one internal term failed to resolve because it was not
cross-linked from anything indexed, and the reconstructing agent
introduced an unrequested observation of its own.
- Stranger-run trials: none reported in ledger format.
That is a small n in the weakest evidence class, and it is stated that way
deliberately. What it supports is narrow and real: across the runs logged, the
mechanics have come back recovered, with drift confined to wording and to one
addition, and with no recorded inversion.
4.1 What raising n does and does not buy
Volume is available â the same probes can be run across every consumer front
end with web access, at no cost, which is itself a consequence of the
constraint in §3. Two cautions govern what that produces.
Author-run trials remain the weakest evidence class regardless of n. Class is
determined by who selected the query and who scored the result, not by how
many times it was done. Five hundred author-run trials produce a measured rate
within the weakest class, which is a genuine improvement over five, and is not
a change of class.
A run set with no failures in it has no discriminating power. The 2026-08-16
observation in which a common-name-plus-common-word query returned a generic
result, with the corpus appearing only below the synthesis, is worth more than
several successes: it locates the boundary of the recovery property, and it
matches the retrieval rule the local implementation already encodes â that a
shared ordinary word is not a match. Runs should be pre-registered, including
predicted misses, and misses should be logged.
MPLPB and the Cost of Visibility
Comparable Machine-Recoverable Continuity at Consumer Cost
Mitchell D. McPhetridge Independent Researcher
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Field Value
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Document ID MPLPB-COST-012
Category Specification / Economic Analysis
Subcategory Knowledge Infrastructure
Updated 2026-08-26T00:00Z v2
Owner Mitchell D. McPhetridge, Independent
Researcher
Status current
Scope The cost structure of
machine-recoverable knowledge; what
MPLPB supplies relative to API-based
RAG and protocol-based context
delivery; the consumer-hardware
constraint under which the public
corpus was built; where the resulting
architecture is and is not an
appropriate deployment choice
When to use Deciding whether a knowledge corpus
needs a retrieval stack; scoping
AI-visible knowledge work at an
individual, independent, or small-lab
budget; evaluating what a
structure-first corpus does and does
not supply
Supersedes MPLPB and the Cost of Visibility: Why
Machine-Recoverable Knowledge Does Not
Require Expensive Retrieval
Infrastructure (2026, no identifier
assigned). Supersession recorded by
title; the prior draft carried no
header block.
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Related. Smart Local MPLPB: A Retrieval-Bounded Front End for a Local Web
(MPLPB-SMART-011 v1 · local · current) â the reference reader. MPLPB as a
Local Web (MPLPB-LOCAL-008 v4) â the corpus specification. Multi-Platform
Linked Public Building for Stateless AI Continuity (v3) â the public framework
and the Question A/B/C separation. MPLPB as a Public Experiment â
Multi-Apparatus Edition (MPLPB-TEST-002 v2.0) â the replication protocol and
trial ledger.
Back to. Main Index > Specification / Architecture Sub-Index
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