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<rfc xmlns:xi="http://www.w3.org/2001/XInclude"
     ipr="trust200902"
     docName="draft-aevum-itt-l-00"
     category="info"
     submissionType="independent"
     xml:lang="en"
     version="3">

  <front>
    <title abbrev="ITT-L">
      Iron Triangle Trace for Longevity (ITT-L): A PACR
      Application Payload Format for Gene-Level Longevity Data
    </title>

    <seriesInfo name="Internet-Draft" value="draft-aevum-itt-l-00"/>

    <author fullname="Kwai Lap Tsoi" initials="K." surname="Tsoi">
      <organization>Aevum Network</organization>
      <address>
        <email>kwailapt@gmail.com</email>
        <uri>https://github.com/kwailapt/EON</uri>
      </address>
    </author>

    <date year="2026" month="May" day="15"/>

    <area>Applications</area>
    <workgroup>Individual Submission</workgroup>

    <keyword>longevity</keyword>
    <keyword>iron-triangle</keyword>
    <keyword>genomics</keyword>
    <keyword>proteomics</keyword>
    <keyword>epigenetics</keyword>
    <keyword>PACR</keyword>
    <keyword>payload-format</keyword>

    <abstract>
      <t>
        This document defines Iron Triangle Trace for Longevity (ITT-L), a
        domain-specific Application Payload Format carried within the PACR
        (Physical and Causal Auditable Record) envelope. Each ITT-L record
        binds four measurement facets — gene, mechanism, drug/metabolite, and
        epigenetic — into a single independently-citable asset with causal
        predecessor chain (Π) integrity provided by the PACR transport layer.
        ITT-L is NOT a standalone protocol; it is a payload format that
        leverages PACR for physical proof (Λ, Landauer cost) and causal
        ordering (Π chain), and AgentCard for service identity.
      </t>
    </abstract>
  </front>

  <middle>

    <section anchor="introduction">
      <name>Introduction</name>
      <t>
        Longevity research produces data across multiple measurement layers:
        genomic variants, proteomic drug targets, metabolic pathway
        participants, and epigenetic clock markers. These data are typically
        stored in heterogeneous databases with no common citation format,
        making cross-layer validation and third-party reproducibility
        difficult.
      </t>
      <t>
        ITT-L addresses this by defining a standardized JSON payload format
        that binds all four measurement layers per gene into a single record.
        Each ITT-L record is carried inside a PACR envelope, which provides:
      </t>
      <ul>
        <li><strong>ι</strong> (CausalId): 128-bit unique record identity</li>
        <li><strong>Π</strong> (predecessor chain): causal ordering of DoD
        validation steps</li>
        <li><strong>Λ</strong> (Landauer cost): physical proof that record
        generation consumed real computational resources</li>
        <li><strong>Ω</strong> (resource triple): energy, time, and space
        consumed</li>
        <li><strong>Γ</strong> (cognitive split): statistical complexity vs.
        entropy rate (S_T/H_T)</li>
      </ul>
      <t>
        ITT-L is complementary to <xref target="I-D.draft-aevum-agentcard"/>,
        which declares agent identity and capabilities, and
        <xref target="I-D.draft-aevum-causal-intervention-record"/>, which
        defines the PACR transport envelope.
      </t>
    </section>

    <section anchor="terminology">
      <name>Terminology</name>
      <t>
        The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
        "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
        "OPTIONAL" in this document are to be interpreted as described in BCP
        14 <xref target="RFC2119"/> <xref target="RFC8174"/> when, and only
        when, they appear in all capitals, as shown here.
      </t>
      <dl>
        <dt>ITT-L Record:</dt>
        <dd>One Iron Triangle Trace for Longevity payload, carried inside
        the body(P) field of a PACR envelope.</dd>
        <dt>Facet:</dt>
        <dd>One of the four measurement dimensions: gene_facet,
        mechanism_facet, drug_metabolite_facet, or epigenetic_facet.</dd>
        <dt>Coupling Edge:</dt>
        <dd>A measurement of information fidelity between two facets (e.g.,
        gene→protein translation fidelity). May be unmeasured (honest
        marker).</dd>
        <dt>H_ITT_gene:</dt>
        <dd>A composite health index per gene, ∈ [0,1], computed as the
        product of facet completeness, facet consistency, and edge factor.</dd>
        <dt>DoD (Definition of Done):</dt>
        <dd>A 7-condition validation gate (D1-D7) applied to each gene
        before ITT-L record generation.</dd>
      </dl>
    </section>

    <section anchor="payload-structure">
      <name>Payload Structure</name>
      <t>
        An ITT-L payload is a JSON object carried in the body(P) field of a
        PACR Application Payload. The JSON Schema is defined at
        <eref target="https://eon.aevum.network/itt-l-schema-v1.json"/>.
      </t>

      <section anchor="required-fields">
        <name>Required Fields</name>
        <t>The following fields MUST be present in every ITT-L payload:</t>
        <ul spacing="compact">
          <li><tt>record_type</tt>: MUST be the string
          "iron_triangle_trace_l".</li>
          <li><tt>schema_version</tt>: MUST be "1.0".</li>
          <li><tt>gene_facet</tt>: object with gene_symbol (string) and
          causal_score (number).</li>
          <li><tt>mechanism_facet</tt>: object with KEGG/Reactome pathway data
          and a mechanism_partial boolean (honest marker).</li>
          <li><tt>drug_metabolite_facet</tt>: object with DrugBank entries,
          AlphaFold pLDDT, and metabolites.</li>
          <li><tt>coupling_edges</tt>: object with three sub-objects
          (gene_protein, protein_epi, epi_gene), each containing value (number
          or null), status (enum: unmeasured, estimated, measured,
          blocked_external_data), and source (string or null).</li>
          <li><tt>h_itt_gene</tt>: number ∈ [0,1], computed as
          facet_completeness × facet_consistency × (1 + edges_measured/3) / 2.
          This formula is frozen in v1.0.</li>
        </ul>
      </section>

      <section anchor="optional-fields">
        <name>Optional Fields</name>
        <t>The following fields MAY be present:</t>
        <ul spacing="compact">
          <li><tt>epigenetic_facet</tt>: object with EPI-score, Horvath CpG
          count, and epigenetic modifier status.</li>
          <li><tt>discovery_class</tt>: enum "novel" | "drug_ready", indicating
          the DoD track that produced this record.</li>
          <li><tt>auto_discovered</tt>: boolean indicating whether the record
          was generated by the ITT-grower daemon rather than human curation.</li>
        </ul>
      </section>
    </section>

    <section anchor="coupling-edges">
      <name>Coupling Edges</name>
      <t>
        The three coupling edges map to the iron triangle framework described
        in <xref target="I-D.veneter"/>: genome, proteome, and epigenome form
        three vertices; the edges measure information flow fidelity between
        them.
      </t>
      <dl>
        <dt>gene_protein:</dt>
        <dd>Translation fidelity — mRNA-to-protein correlation. Measurement
        operator: Ribosome Profiling + proteomics Pearson r (Frobenius norm).</dd>
        <dt>protein_epi:</dt>
        <dd>Modification fidelity — SIRT1 activity × DNMT3A methylation
        maintenance rate, normalized to [0,1].</dd>
        <dt>epi_gene:</dt>
        <dd>Regulatory fidelity — ATAC-seq open chromatin peak overlap at
        FOXO3 binding sites.</dd>
      </dl>
      <t>
        In ITT-L v1.0, all coupling edges default to status "unmeasured" —
        this is an honest marker, not a data gap. Edges transition to
        "measured" when the corresponding measurement operator produces a
        value. The edge_factor component of H_ITT_gene increases from 0.5
        (all unmeasured) toward 1.0 (all measured), providing a built-in
        incentive for edge measurement without penalizing records that
        legitimately lack measurement data.
      </t>
    </section>

    <section anchor="falsifiability">
      <name>Falsifiability Considerations</name>
      <t>
        ITT-L is designed as an engineering protocol that also supports
        scientific falsifiability. Four falsifiable predictions are defined
        in the companion Falsifiability Manifest
        (EON-ITT-L-FALSIFIABILITY-MANIFEST.md):
      </t>
      <ol spacing="compact">
        <li><strong>F1 (Intervention Effect)</strong>: novel 6/6 genes show
        Horvath Δage ≤ -3 years after intervention. Falsified if ≥30 wet-lab
        records show otherwise.</li>
        <li><strong>F2 (Coupling Prediction)</strong>: high protein_epi genes
        show greater intervention ROI (r ≥ 0.2). Falsified if correlation is
        below threshold.</li>
        <li><strong>F3 (H_ITT Predictive Power)</strong>: genes with
        h_itt_gene ≥ 0.7 are adopted as clinical trial targets at a higher
        rate than baseline. Falsified if p ≥ 0.05.</li>
        <li><strong>F4 (Facet Completeness)</strong>: complete 4-facet genes
        show higher D7 wet-lab pass rates than incomplete genes. Falsified if
        p ≥ 0.05.</li>
      </ol>
    </section>

    <section anchor="security">
      <name>Security Considerations</name>
      <t>
        ITT-L does not introduce new security considerations beyond those
        already described in the PACR transport specification
        <xref target="I-D.draft-aevum-causal-intervention-record"/>. The
        following considerations apply:
      </t>
      <ul>
        <li>Λ (Landauer cost) provides a physical lower bound on forgery cost
        — any attacker attempting to inject fraudulent ITT-L records MUST
        spend at least LANDAUER_JOULES_300K (≈2.87 × 10⁻²¹ J) per bit of
        erased information. While individually small, this cost scales
        linearly with record size and count, making bulk forgery detectable
        through energy anomaly.</li>
        <li>The Π (predecessor) chain ensures that any ITT-L record's causal
        ancestry can be independently verified without trusting the EON
        service.</li>
        <li>Sensitive gene data (e.g., rare variant information) is public
        research data derived from UK Biobank, GTEx, and PubMed. No
        personally identifiable information is stored in ITT-L records.</li>
      </ul>
    </section>

    <section anchor="iana">
      <name>IANA Considerations</name>
      <t>
        This document requests the registration of the following media type:
      </t>
      <dl>
        <dt>Type name:</dt><dd>application</dd>
        <dt>Subtype name:</dt><dd>eon-itt-l+json</dd>
        <dt>Required parameters:</dt><dd>N/A</dd>
        <dt>Optional parameters:</dt><dd>N/A</dd>
        <dt>Encoding considerations:</dt><dd>binary (UTF-8 JSON)</dd>
        <dt>Security considerations:</dt><dd>See Security Considerations
        (Section 6) of this document.</dd>
        <dt>Interoperability considerations:</dt><dd>Payload MUST validate
        against the JSON Schema at
        https://eon.aevum.network/itt-l-schema-v1.json</dd>
        <dt>Published specification:</dt><dd>This document</dd>
        <dt>Applications that use this media type:</dt><dd>EON Longevity
        Target Discovery system</dd>
        <dt>Fragment identifier considerations:</dt><dd>N/A</dd>
        <dt>Restrictions on usage:</dt><dd>N/A</dd>
        <dt>Provisional registration:</dt><dd>Yes</dd>
      </dl>
    </section>

  </middle>

  <back>
    <references>
      <name>Normative References</name>
      <reference anchor="RFC2119" target="https://www.rfc-editor.org/info/rfc2119">
        <front><title>Key words for use in RFCs to Indicate Requirement Levels</title>
        <author initials="S." surname="Bradner"/><date year="1997" month="March"/>
        </front>
      </reference>
      <reference anchor="RFC8174" target="https://www.rfc-editor.org/info/rfc8174">
        <front><title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
        <author initials="B." surname="Leiba"/><date year="2017" month="May"/>
        </front>
      </reference>
    </references>

    <references>
      <name>Informative References</name>
      <reference anchor="I-D.draft-aevum-agentcard" target="https://datatracker.ietf.org/doc/draft-aevum-agentcard/">
        <front><title>AgentCard: A Framework-Neutral Identity and Capability Declaration Format</title>
        <author fullname="Kwai Lap Tsoi" initials="K." surname="Tsoi"/>
        <date year="2026" month="April" day="23"/>
        </front>
      </reference>
      <reference anchor="I-D.draft-aevum-causal-intervention-record" target="https://datatracker.ietf.org/doc/draft-aevum-causal-intervention-record/">
        <front><title>Causal Intervention Record (PACR): A Physics-Grounded Audit Trail for Agent Actions</title>
        <author fullname="Kwai Lap Tsoi" initials="K." surname="Tsoi"/>
        <date year="2026" month="April" day="26"/>
        </front>
      </reference>
      <reference anchor="I-D.veneter" target="https://github.com/kwailapt/EON">
        <front><title>Iron Triangle of Longevity Research</title>
        <author fullname="Craig Venter"/><date year="2026" month="April"/>
        </front>
      </reference>
    </references>
  </back>

</rfc>
