merge vouching+translog: web-of-trust + signed merkle audit log

# Conflicts:
#	src/psyc/_federation_cli.py
#	src/psyc/cockpit/federation_routes.py

src/psyc/_federation_cli.py

@@ -13,7 +13,7 @@ import httpx
 import typer
 
 from psyc import db, log
-from psyc.lines import discovery, federation, pulse
+from psyc.lines import discovery, federation, pulse, translog
 from psyc.result import Err, Ok
 
 
@@ -210,3 +210,80 @@ def register(typer_app: typer.Typer) -> None:
         seeds = [s for s in seeds if s != d]
         pulse.set_discovery_seeds(seeds)
         typer.echo(f"removed seed {d}")
+
+    # ---------- vouching + quorum --------------------------------------
+
+    @typer_app.command("fed-vouch")
+    def fed_vouch(
+        target_fp: str = typer.Argument(..., help="target peer fingerprint (32 hex)"),
+        ttl_days: int = typer.Option(90, "--ttl-days", help="vouch lifetime in days"),
+    ) -> None:
+        """Issue a signed vouch for `target_fp`. Persists locally + rides our feed."""
+        db.init_db()
+        v = federation.issue_vouch(target_fp.strip(), ttl_days=ttl_days)
+        typer.echo(f"vouched: {v.target_fingerprint} (expires {v.expires_at})")
+
+    @typer_app.command("fed-unvouch")
+    def fed_unvouch(target_fp: str = typer.Argument(...)) -> None:
+        """Revoke OUR vouch for `target_fp`."""
+        db.init_db()
+        federation.revoke_vouch(target_fp.strip())
+        typer.echo(f"revoked vouch for {target_fp}")
+
+    @typer_app.command("fed-vouches")
+    def fed_vouches() -> None:
+        """List vouches WE have issued."""
+        db.init_db()
+        rows = federation.our_vouches()
+        if not rows:
+            typer.echo("(no vouches issued)")
+            return
+        for v in rows:
+            exp = v.expires_at.isoformat() if v.expires_at else "—"
+            typer.echo(f"  {v.target_fingerprint}  issued={v.issued_at.isoformat()[:16]}  expires={exp[:16]}")
+
+    @typer_app.command("fed-quorum-set")
+    def fed_quorum_set(
+        trust: Optional[int] = typer.Option(None, "--trust", help="trust_min_vouchers"),
+        k: Optional[int] = typer.Option(None, "--k", help="signal_quorum_k"),
+    ) -> None:
+        """Update quorum thresholds. Either flag is optional — only changed values overwrite."""
+        db.init_db()
+        cfg = federation.quorum_config()
+        if trust is not None:
+            cfg.trust_min_vouchers = max(1, int(trust))
+        if k is not None:
+            cfg.signal_quorum_k = max(1, int(k))
+        federation.set_quorum_config(cfg)
+        typer.echo(f"quorum: trust_min_vouchers={cfg.trust_min_vouchers}  signal_quorum_k={cfg.signal_quorum_k}")
+
+    # ---------- transparency log --------------------------------------
+
+    @typer_app.command("fed-log")
+    def fed_log(
+        limit: int = typer.Option(20, "--limit", help="number of entries to show"),
+    ) -> None:
+        """Print recent transparency-log entries (newest first)."""
+        db.init_db()
+        rows = translog.recent(limit=limit)
+        if not rows:
+            typer.echo("(transparency log empty)")
+            return
+        for e in rows:
+            typer.echo(
+                f"  id={e.id:5d}  {e.entry_type:6s}  {e.timestamp[:19]}  hash={e.entry_hash[:16]}…"
+            )
+
+    @typer_app.command("fed-log-verify")
+    def fed_log_verify() -> None:
+        """Re-walk the chain locally and report verification status."""
+        db.init_db()
+        result = translog.verify_chain()
+        head = translog.head()
+        head_hash = head.entry_hash if head else "(empty)"
+        if isinstance(result, Err):
+            typer.echo(f"  ✗ broken: {result.reason}", err=True)
+            typer.echo(f"    head_hash: {head_hash}")
+            raise typer.Exit(1)
+        typer.echo(f"  ✓ verified {result.value} entries")
+        typer.echo(f"    head_hash: {head_hash}")

src/psyc/cockpit/federation_routes.py

@@ -15,7 +15,8 @@ from fastapi.responses import HTMLResponse, JSONResponse, PlainTextResponse, Red
 from fastapi.templating import Jinja2Templates
 
 from psyc import db, log
-from psyc.lines import discovery, federation, pulse
+from psyc.lines import discovery, federation, pulse, translog
+from psyc.result import Err
 
 
 _log = log.get(__name__)
@@ -191,4 +192,183 @@ def register(app: FastAPI, TEMPLATES: Jinja2Templates) -> None:
         """
         return JSONResponse(_cached_public_peers())
 
+    # ---------- public vouches + transparency log --------------------
+
+    @app.get("/federation/vouches")
+    def federation_vouches() -> JSONResponse:
+        """Vouches WE have issued. Peers fetch this to learn who we trust."""
+        return JSONResponse({
+            "fingerprint": federation.node_fingerprint(),
+            "vouches": [v.model_dump(mode="json") for v in federation.our_vouches()],
+        })
+
+    @app.get("/federation/log")
+    def federation_log() -> JSONResponse:
+        """Last 100 transparency-log entries, newest first."""
+        entries = translog.recent(limit=100)
+        return JSONResponse({
+            "count": len(entries),
+            "entries": [e.model_dump(mode="json") for e in entries],
+        })
+
+    @app.get("/federation/log/verify")
+    def federation_log_verify() -> JSONResponse:
+        """Re-walk the chain locally and report status. Auditors poll this."""
+        result = translog.verify_chain()
+        head = translog.head()
+        head_hash = head.entry_hash if head else None
+        if isinstance(result, Err):
+            return JSONResponse({"error": result.reason, "head_hash": head_hash}, status_code=409)
+        return JSONResponse({"verified": result.value, "head_hash": head_hash})
+
+    # ---------- admin: vouches page ---------------------------------
+
+    @app.get("/admin/federation/vouches", response_class=HTMLResponse)
+    def admin_federation_vouches(request: Request) -> HTMLResponse:
+        if not _admin_ok(request):
+            return RedirectResponse("/admin", status_code=303)
+        peers = federation.list_peers()
+        cfg = federation.quorum_config()
+        ours = federation.our_vouches()
+        # Per-peer view: vouches naming each peer and whether quorum is met.
+        peer_rows = []
+        for p in peers:
+            vouches = federation.vouches_for(p.fingerprint)
+            peer_rows.append({
+                "peer": p,
+                "vouches": vouches,
+                "vouched": federation.is_vouched(p.fingerprint),
+                "eligible": federation.peer_is_listening_eligible(p.fingerprint),
+            })
+        return TEMPLATES.TemplateResponse(
+            request,
+            "admin_federation_vouches.html",
+            {
+                "fingerprint": federation.node_fingerprint(),
+                "our_vouches": ours,
+                "peer_rows": peer_rows,
+                "cfg": cfg,
+            },
+        )
+
+    @app.post("/admin/federation/vouches/issue")
+    def admin_federation_vouch_issue(
+        request: Request,
+        target_fingerprint: str = Form(...),
+        ttl_days: int = Form(90),
+    ) -> RedirectResponse:
+        if not _admin_ok(request):
+            raise HTTPException(status_code=403, detail="admin session required")
+        try:
+            federation.issue_vouch(target_fingerprint.strip(), ttl_days=ttl_days)
+        except Exception as exc:
+            _log.warning("federation.vouch.issue.error", error=str(exc))
+        return RedirectResponse("/admin/federation/vouches", status_code=303)
+
+    @app.post("/admin/federation/vouches/revoke")
+    def admin_federation_vouch_revoke(
+        request: Request,
+        target_fingerprint: str = Form(...),
+    ) -> RedirectResponse:
+        if not _admin_ok(request):
+            raise HTTPException(status_code=403, detail="admin session required")
+        federation.revoke_vouch(target_fingerprint.strip())
+        return RedirectResponse("/admin/federation/vouches", status_code=303)
+
+    # ---------- admin: transparency log page ------------------------
+
+    @app.get("/admin/federation/log", response_class=HTMLResponse)
+    def admin_federation_log(request: Request) -> HTMLResponse:
+        if not _admin_ok(request):
+            return RedirectResponse("/admin", status_code=303)
+        result = translog.verify_chain()
+        head = translog.head()
+        entries = translog.recent(limit=200)
+        verify_status: Dict[str, Any]
+        if isinstance(result, Err):
+            verify_status = {"ok": False, "reason": result.reason}
+        else:
+            verify_status = {"ok": True, "verified": result.value}
+        return TEMPLATES.TemplateResponse(
+            request,
+            "admin_federation_log.html",
+            {
+                "verify_status": verify_status,
+                "head_hash": head.entry_hash if head else "",
+                "head_id": head.id if head else 0,
+                "entries": entries,
+            },
+        )
+
+    # ---------- admin: quorum config + per-peer/per-hash view -------
+
+    @app.get("/admin/federation/quorum", response_class=HTMLResponse)
+    def admin_federation_quorum(request: Request) -> HTMLResponse:
+        if not _admin_ok(request):
+            return RedirectResponse("/admin", status_code=303)
+        cfg = federation.quorum_config()
+        peers = federation.list_peers()
+        peer_rows = [
+            {
+                "peer": p,
+                "vouched": federation.is_vouched(p.fingerprint),
+                "eligible": federation.peer_is_listening_eligible(p.fingerprint),
+            }
+            for p in peers
+        ]
+        # Group buffered signals by signal_hash and count distinct eligible peers.
+        signal_rows: Dict[str, Dict[str, Any]] = {}
+        for s in db.recent_signals(limit=500):
+            h = s.get("signal_hash") or ""
+            entry = signal_rows.setdefault(h, {
+                "signal_hash": h,
+                "signal_type": s.get("signal_type") or "",
+                "signal_id": s.get("signal_id") or "",
+                "peers": set(),
+                "latest": s.get("received_at") or "",
+            })
+            entry["peers"].add(s.get("peer_fingerprint") or "")
+        hash_summary = []
+        for h, row in signal_rows.items():
+            distinct_eligible = sum(
+                1 for fp in row["peers"] if federation.peer_is_listening_eligible(fp)
+            )
+            hash_summary.append({
+                "signal_hash": h,
+                "signal_type": row["signal_type"],
+                "signal_id": row["signal_id"],
+                "distinct_peers": len(row["peers"]),
+                "distinct_eligible": distinct_eligible,
+                "quorum_met": distinct_eligible >= cfg.signal_quorum_k,
+                "latest": row["latest"],
+            })
+        hash_summary.sort(key=lambda r: r["latest"], reverse=True)
+        return TEMPLATES.TemplateResponse(
+            request,
+            "admin_federation_quorum.html",
+            {
+                "cfg": cfg,
+                "peer_rows": peer_rows,
+                "hash_summary": hash_summary,
+            },
+        )
+
+    @app.post("/admin/federation/quorum/save")
+    def admin_federation_quorum_save(
+        request: Request,
+        trust_min_vouchers: int = Form(...),
+        signal_quorum_k: int = Form(...),
+    ) -> RedirectResponse:
+        if not _admin_ok(request):
+            raise HTTPException(status_code=403, detail="admin session required")
+        try:
+            cfg = federation.QuorumConfig(
+                trust_min_vouchers=max(1, int(trust_min_vouchers)),
+                signal_quorum_k=max(1, int(signal_quorum_k)),
+            )
+            federation.set_quorum_config(cfg)
+        except Exception as exc:
+            _log.warning("federation.quorum.save.error", error=str(exc))
+        return RedirectResponse("/admin/federation/quorum", status_code=303)
+
     _log.info("federation.routes.registered")

src/psyc/cockpit/templates/admin_federation.html

@@ -8,7 +8,7 @@
     <span class="count">{{ peers|length }} peer{{ '' if peers|length == 1 else 's' }}</span>
   </div>
   <p class="page-intro">This node's Ed25519 identity. The fingerprint goes into a DNS TXT record so other psyc nodes can discover this one. The public key lets them verify any feed we publish — the private key never leaves this box.</p>
-  <p class="back"><a href="/admin">← back to admin</a></p>
+  <p class="back"><a href="/admin">← back to admin</a> &nbsp;·&nbsp; <a href="/admin/federation/vouches">vouches</a> &nbsp;·&nbsp; <a href="/admin/federation/quorum">quorum config</a> &nbsp;·&nbsp; <a href="/admin/federation/log">transparency log</a></p>
 
   <div class="card" style="margin-bottom:14px;">
     <div class="lg-sub">node fingerprint</div>

src/psyc/cockpit/templates/admin_federation_log.html

@@ -0,0 +1,63 @@
+{% extends "base.html" %}
+{% block title %}Transparency Log — psyc admin{% endblock %}
+{% block content %}
+
+<section class="panel">
+  <div class="panel-head">
+    <h1>Transparency Log</h1>
+    <span class="count">id @ {{ head_id }}</span>
+  </div>
+  <p class="page-intro">Every signal we accept from a peer is appended to a signed merkle chain. Each entry references the previous entry's hash, so tampering with any historical row invalidates every entry after. Auditors can re-walk and detect a bad peer historically — even one we trusted at the time.</p>
+  <p class="back"><a href="/admin/federation">← back to federation</a> &nbsp;·&nbsp; <a href="/admin/federation/vouches">vouches</a> &nbsp;·&nbsp; <a href="/admin/federation/quorum">quorum config</a> &nbsp;·&nbsp; <a href="/federation/log/verify">public verify endpoint</a></p>
+
+  <div class="card" style="margin-bottom:14px;">
+    <div class="lg-sub">chain verification</div>
+    {% if verify_status.ok %}
+      <div style="margin:6px 0;"><span class="sev-badge" style="background:rgba(74,222,128,0.10); color:var(--green); border-color:var(--green);">verified</span> &nbsp; {{ verify_status.verified }} entries walked, no breaks</div>
+    {% else %}
+      <div style="margin:6px 0;"><span class="sev-badge" style="background:rgba(248,113,113,0.10); color:var(--red); border-color:var(--red);">BROKEN</span> &nbsp; {{ verify_status.reason }}</div>
+    {% endif %}
+    {% if head_hash %}
+      <div class="lg-sub" style="margin-top:8px;">head hash</div>
+      <div style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace; font-size:13px; word-break:break-all; color:var(--accent);">{{ head_hash }}</div>
+    {% endif %}
+  </div>
+</section>
+
+<section class="panel">
+  <div class="panel-head">
+    <h2>Recent Entries</h2>
+    <span class="count">{{ entries|length }} of last 200</span>
+  </div>
+  <p class="page-intro">Newest first. Hashes are truncated for display — full values are at <code>/federation/log</code>.</p>
+
+  {% if entries %}
+  <table class="ledger">
+    <thead><tr><th>id</th><th>When</th><th>Type</th><th>Peer / target</th><th>Signal id</th><th>Hash</th></tr></thead>
+    <tbody>
+    {% for e in entries %}
+      <tr class="ledger-row">
+        <td>{{ e.id }}</td>
+        <td class="lg-ts">{{ (e.timestamp or '')[:19] | replace('T', ' ') }}</td>
+        <td><span class="sev-badge">{{ e.entry_type }}</span></td>
+        <td class="lg-sub" style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace; font-size:11.5px;">
+          {% if e.entry_type == 'signal' %}
+            {{ (e.entry_data.peer_fingerprint or '')[:8] }}…
+          {% elif e.entry_type == 'vouch' %}
+            {{ (e.entry_data.voucher_fingerprint or '')[:8] }}…→{{ (e.entry_data.target_fingerprint or '')[:8] }}…
+          {% else %}
+            —
+          {% endif %}
+        </td>
+        <td style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace; font-size:11.5px;">{{ ((e.entry_data.signal_id or e.entry_data.target_fingerprint or '') | string)[:32] }}</td>
+        <td class="lg-sub" style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace; font-size:11.5px;">{{ e.entry_hash[:16] }}…</td>
+      </tr>
+    {% endfor %}
+    </tbody>
+  </table>
+  {% else %}
+  <p class="page-intro">(chain empty — no signals appended yet)</p>
+  {% endif %}
+</section>
+
+{% endblock %}

src/psyc/cockpit/templates/admin_federation_quorum.html

@@ -0,0 +1,92 @@
+{% extends "base.html" %}
+{% block title %}Quorum Config — psyc admin{% endblock %}
+{% block content %}
+
+<section class="panel">
+  <div class="panel-head">
+    <h1>Quorum Configuration</h1>
+    <span class="count">trust={{ cfg.trust_min_vouchers }} k={{ cfg.signal_quorum_k }}</span>
+  </div>
+  <p class="page-intro"><strong>trust_min_vouchers</strong> — distinct trusted vouchers required to make a new peer listening-eligible. <strong>signal_quorum_k</strong> — distinct listening-eligible peers required to consider a signal_hash quorum-met. Both gates live in pulse_settings; raising them tightens trust, lowering them relaxes it.</p>
+  <p class="back"><a href="/admin/federation">← back to federation</a> &nbsp;·&nbsp; <a href="/admin/federation/vouches">vouches</a> &nbsp;·&nbsp; <a href="/admin/federation/log">transparency log</a></p>
+
+  <form method="post" action="/admin/federation/quorum/save" style="display:grid; gap:10px; max-width:520px;">
+    <label class="lg-sub">trust_min_vouchers</label>
+    <input type="number" name="trust_min_vouchers" value="{{ cfg.trust_min_vouchers }}" min="1" max="50" class="lookup-input" required>
+    <label class="lg-sub">signal_quorum_k</label>
+    <input type="number" name="signal_quorum_k" value="{{ cfg.signal_quorum_k }}" min="1" max="50" class="lookup-input" required>
+    <button type="submit" class="btn btn-enforce">save config</button>
+  </form>
+</section>
+
+<section class="panel">
+  <div class="panel-head">
+    <h2>Per-Peer Listening Eligibility</h2>
+    <span class="count">{{ peer_rows|length }}</span>
+  </div>
+  <p class="page-intro">A peer's feed gets ingested only when its fingerprint is eligible (directly trusted or vouched into trust).</p>
+
+  {% if peer_rows %}
+  <table class="ledger">
+    <thead><tr><th>Domain</th><th>Fingerprint</th><th>Status</th><th>Vouched</th><th>Eligible</th></tr></thead>
+    <tbody>
+    {% for row in peer_rows %}
+      <tr class="ledger-row">
+        <td><strong>{{ row.peer.domain }}</strong></td>
+        <td class="lg-sub" style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace;">{{ row.peer.fingerprint[:8] }}…{{ row.peer.fingerprint[-8:] }}</td>
+        <td>
+          {% if row.peer.status == 'trusted' %}
+            <span class="sev-badge" style="background:rgba(74,222,128,0.10); color:var(--green); border-color:var(--green);">trusted</span>
+          {% elif row.peer.status == 'blocked' %}
+            <span class="sev-badge" style="background:rgba(248,113,113,0.10); color:var(--red); border-color:var(--red);">blocked</span>
+          {% else %}
+            <span class="sev-badge">{{ row.peer.status }}</span>
+          {% endif %}
+        </td>
+        <td>{% if row.vouched %}<span class="sev-badge" style="background:rgba(74,222,128,0.10); color:var(--green); border-color:var(--green);">yes</span>{% else %}<span class="sev-badge">no</span>{% endif %}</td>
+        <td>{% if row.eligible %}<span class="sev-badge" style="background:rgba(74,222,128,0.10); color:var(--green); border-color:var(--green);">listening</span>{% else %}<span class="sev-badge" style="background:rgba(248,113,113,0.10); color:var(--red); border-color:var(--red);">muted</span>{% endif %}</td>
+      </tr>
+    {% endfor %}
+    </tbody>
+  </table>
+  {% else %}
+  <p class="page-intro">(no peers registered yet)</p>
+  {% endif %}
+</section>
+
+<section class="panel">
+  <div class="panel-head">
+    <h2>Signal Hashes in Buffer</h2>
+    <span class="count">{{ hash_summary|length }} hashes</span>
+  </div>
+  <p class="page-intro">Distinct eligible-peer counts per signal hash. Quorum is met when count ≥ {{ cfg.signal_quorum_k }}.</p>
+
+  {% if hash_summary %}
+  <table class="ledger">
+    <thead><tr><th>Latest</th><th>Type</th><th>Signal id</th><th>Hash</th><th>Distinct peers</th><th>Eligible</th><th>Quorum</th></tr></thead>
+    <tbody>
+    {% for r in hash_summary %}
+      <tr class="ledger-row">
+        <td class="lg-ts">{{ (r.latest or '')[:19] | replace('T', ' ') }}</td>
+        <td><span class="sev-badge">{{ r.signal_type }}</span></td>
+        <td style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace; font-size:11.5px;">{{ r.signal_id[:48] }}</td>
+        <td class="lg-sub" style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace; font-size:11.5px;">{{ r.signal_hash[:16] }}…</td>
+        <td>{{ r.distinct_peers }}</td>
+        <td>{{ r.distinct_eligible }}</td>
+        <td>
+          {% if r.quorum_met %}
+            <span class="sev-badge" style="background:rgba(74,222,128,0.10); color:var(--green); border-color:var(--green);">met</span>
+          {% else %}
+            <span class="sev-badge">below</span>
+          {% endif %}
+        </td>
+      </tr>
+    {% endfor %}
+    </tbody>
+  </table>
+  {% else %}
+  <p class="page-intro">(no signals in buffer yet)</p>
+  {% endif %}
+</section>
+
+{% endblock %}

src/psyc/cockpit/templates/admin_federation_vouches.html

@@ -0,0 +1,110 @@
+{% extends "base.html" %}
+{% block title %}Federation Vouches — psyc admin{% endblock %}
+{% block content %}
+
+<section class="panel">
+  <div class="panel-head">
+    <h1>Web of Trust</h1>
+    <span class="count">{{ our_vouches|length }} issued</span>
+  </div>
+  <p class="page-intro">A vouch is an Ed25519-signed assertion that we trust another node's fingerprint. Peers gossip our vouches with their feeds, so trust accumulates: once {{ cfg.trust_min_vouchers }} of our trusted peers vouches for a new fingerprint, it becomes <em>listening-eligible</em> — its signed feeds get ingested.</p>
+  <p class="back"><a href="/admin/federation">← back to federation</a> &nbsp;·&nbsp; <a href="/admin/federation/quorum">quorum config</a> &nbsp;·&nbsp; <a href="/admin/federation/log">transparency log</a></p>
+
+  <div class="card" style="margin-bottom:14px;">
+    <div class="lg-sub">our fingerprint</div>
+    <div style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace; font-size:14px; word-break:break-all; color:var(--accent);">{{ fingerprint }}</div>
+  </div>
+</section>
+
+<section class="panel">
+  <div class="panel-head">
+    <h2>Vouches We've Issued</h2>
+    <span class="count">{{ our_vouches|length }}</span>
+  </div>
+  <p class="page-intro">We've signed these — peers that fetch our feed will see them and may extend trust accordingly.</p>
+
+  {% if our_vouches %}
+  <table class="ledger">
+    <thead><tr><th>Target fingerprint</th><th>Issued</th><th>Expires</th><th></th></tr></thead>
+    <tbody>
+    {% for v in our_vouches %}
+      <tr class="ledger-row">
+        <td style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace; font-size:12px;">{{ v.target_fingerprint }}</td>
+        <td class="lg-ts">{{ v.issued_at.isoformat()[:16] | replace('T', ' ') }}</td>
+        <td class="lg-ts">{{ v.expires_at.isoformat()[:16] | replace('T', ' ') if v.expires_at else '—' }}</td>
+        <td>
+          <form method="post" action="/admin/federation/vouches/revoke" class="queue-action"
+                onsubmit="return confirm('Revoke vouch for {{ v.target_fingerprint[:8] }}…?');">
+            <input type="hidden" name="target_fingerprint" value="{{ v.target_fingerprint }}">
+            <button type="submit" class="btn btn-reject">revoke</button>
+          </form>
+        </td>
+      </tr>
+    {% endfor %}
+    </tbody>
+  </table>
+  {% else %}
+  <p class="page-intro">(no vouches issued yet)</p>
+  {% endif %}
+</section>
+
+<section class="panel">
+  <div class="panel-head">
+    <h2>Issue a Vouch</h2>
+  </div>
+  <p class="page-intro">Vouch for a peer's fingerprint. Trusted peers see this and may treat the target as listening-eligible.</p>
+  <form method="post" action="/admin/federation/vouches/issue" style="display:grid; gap:10px; max-width:680px;">
+    <input type="text" name="target_fingerprint" placeholder="target fingerprint (32 hex chars)" class="lookup-input" maxlength="64" required style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace;">
+    <input type="number" name="ttl_days" value="90" min="1" max="3650" class="lookup-input" placeholder="ttl days">
+    <button type="submit" class="btn btn-enforce">+ issue vouch</button>
+  </form>
+</section>
+
+<section class="panel">
+  <div class="panel-head">
+    <h2>Per-Peer Quorum Status</h2>
+    <span class="count">{{ peer_rows|length }} peers</span>
+  </div>
+  <p class="page-intro">Threshold: {{ cfg.trust_min_vouchers }} distinct trusted vouchers required to make a non-trusted peer listening-eligible.</p>
+
+  {% if peer_rows %}
+  <table class="ledger">
+    <thead><tr><th>Peer</th><th>Status</th><th>Vouches</th><th>Quorum met</th><th>Eligible</th></tr></thead>
+    <tbody>
+    {% for row in peer_rows %}
+      <tr class="ledger-row">
+        <td><strong>{{ row.peer.domain }}</strong><br><span class="lg-sub" style="font-family:ui-monospace,SFMono-Regular,Menlo,monospace;">{{ row.peer.fingerprint[:8] }}…{{ row.peer.fingerprint[-8:] }}</span></td>
+        <td>
+          {% if row.peer.status == 'trusted' %}
+            <span class="sev-badge" style="background:rgba(74,222,128,0.10); color:var(--green); border-color:var(--green);">trusted</span>
+          {% elif row.peer.status == 'blocked' %}
+            <span class="sev-badge" style="background:rgba(248,113,113,0.10); color:var(--red); border-color:var(--red);">blocked</span>
+          {% else %}
+            <span class="sev-badge">{{ row.peer.status }}</span>
+          {% endif %}
+        </td>
+        <td>{{ row.vouches|length }}</td>
+        <td>
+          {% if row.vouched %}
+            <span class="sev-badge" style="background:rgba(74,222,128,0.10); color:var(--green); border-color:var(--green);">yes</span>
+          {% else %}
+            <span class="sev-badge">no</span>
+          {% endif %}
+        </td>
+        <td>
+          {% if row.eligible %}
+            <span class="sev-badge" style="background:rgba(74,222,128,0.10); color:var(--green); border-color:var(--green);">listening</span>
+          {% else %}
+            <span class="sev-badge" style="background:rgba(248,113,113,0.10); color:var(--red); border-color:var(--red);">muted</span>
+          {% endif %}
+        </td>
+      </tr>
+    {% endfor %}
+    </tbody>
+  </table>
+  {% else %}
+  <p class="page-intro">(no peers registered yet)</p>
+  {% endif %}
+</section>
+
+{% endblock %}

src/psyc/db.py

@@ -161,6 +161,35 @@ Index("federation_signals_hash_idx", federation_signals.c.signal_hash)
 Index("federation_signals_peer_idx", federation_signals.c.peer_fingerprint)
 Index("federation_signals_received_idx", federation_signals.c.received_at.desc())
 
+# Web-of-trust vouches — voucher signs an attestation that target is OK to listen to.
+# Quorum is reached when enough distinct trusted vouchers sign for the same target.
+vouches = Table(
+    "vouches", _metadata,
+    Column("id", Integer, primary_key=True, autoincrement=True),
+    Column("voucher_fingerprint", String, nullable=False),
+    Column("target_fingerprint", String, nullable=False),
+    Column("issued_at", String, nullable=False),
+    Column("expires_at", String, nullable=True),
+    Column("signature", Text, nullable=False),       # base64 ed25519 sig
+)
+Index("vouches_unique_idx", vouches.c.voucher_fingerprint, vouches.c.target_fingerprint, unique=True)
+Index("vouches_target_idx", vouches.c.target_fingerprint)
+
+# Transparency log — append-only signed hash chain over every signal we receive.
+# Each entry references the previous entry's hash; tampering with any row breaks
+# verify_chain on every subsequent row.
+translog = Table(
+    "translog", _metadata,
+    Column("id", Integer, primary_key=True, autoincrement=True),
+    Column("prev_hash", String, nullable=False),
+    Column("entry_type", String, nullable=False),    # signal | vouch | config
+    Column("entry_data", Text, nullable=False),      # canonical JSON of payload
+    Column("timestamp", String, nullable=False),
+    Column("entry_hash", String, nullable=False),
+)
+Index("translog_hash_idx", translog.c.entry_hash)
+Index("translog_time_idx", translog.c.timestamp.desc())
+
 
 _log = log.get(__name__)
 _engine: Optional[Engine] = None
@@ -388,3 +417,113 @@ def recent_signals(limit: int = 200, db_path: Path = DB_PATH) -> List[dict]:
     stmt = select(federation_signals).order_by(federation_signals.c.received_at.desc()).limit(limit)
     with engine(db_path).connect() as conn:
         return [dict(r._mapping) for r in conn.execute(stmt).fetchall()]
+
+
+# ---------- federation: pulse_settings get/set (shared scratch kv) -------
+
+def setting_get(key: str, db_path: Path = DB_PATH) -> Optional[str]:
+    """Read one pulse_settings value by key. Returns None if absent."""
+    stmt = select(pulse_settings.c.value).where(pulse_settings.c.key == key)
+    with engine(db_path).connect() as conn:
+        row = conn.execute(stmt).fetchone()
+    return None if row is None else str(row.value)
+
+
+def setting_set(key: str, value: str, db_path: Path = DB_PATH) -> None:
+    """Upsert one pulse_settings entry."""
+    stmt = sqlite_insert(pulse_settings).values(key=key, value=value)
+    stmt = stmt.on_conflict_do_update(
+        index_elements=[pulse_settings.c.key],
+        set_=dict(value=stmt.excluded.value),
+    )
+    with engine(db_path).begin() as conn:
+        conn.execute(stmt)
+
+
+# ---------- federation: vouches ------------------------------------------
+
+def upsert_vouch(row: dict, db_path: Path = DB_PATH) -> None:
+    """Insert-or-update one vouch. Unique on (voucher_fp, target_fp)."""
+    stmt = sqlite_insert(vouches).values(**row)
+    update_cols = {k: stmt.excluded[k] for k in row if k not in ("voucher_fingerprint", "target_fingerprint")}
+    stmt = stmt.on_conflict_do_update(
+        index_elements=[vouches.c.voucher_fingerprint, vouches.c.target_fingerprint],
+        set_=update_cols,
+    )
+    with engine(db_path).begin() as conn:
+        conn.execute(stmt)
+
+
+def list_vouches(db_path: Path = DB_PATH) -> List[dict]:
+    stmt = select(vouches).order_by(vouches.c.issued_at.desc())
+    with engine(db_path).connect() as conn:
+        return [dict(r._mapping) for r in conn.execute(stmt).fetchall()]
+
+
+def vouches_by_target(target_fingerprint: str, db_path: Path = DB_PATH) -> List[dict]:
+    stmt = select(vouches).where(vouches.c.target_fingerprint == target_fingerprint)
+    with engine(db_path).connect() as conn:
+        return [dict(r._mapping) for r in conn.execute(stmt).fetchall()]
+
+
+def vouches_by_voucher(voucher_fingerprint: str, db_path: Path = DB_PATH) -> List[dict]:
+    stmt = select(vouches).where(vouches.c.voucher_fingerprint == voucher_fingerprint)
+    with engine(db_path).connect() as conn:
+        return [dict(r._mapping) for r in conn.execute(stmt).fetchall()]
+
+
+def delete_vouch(voucher_fingerprint: str, target_fingerprint: str, db_path: Path = DB_PATH) -> None:
+    stmt = vouches.delete().where(
+        (vouches.c.voucher_fingerprint == voucher_fingerprint)
+        & (vouches.c.target_fingerprint == target_fingerprint)
+    )
+    with engine(db_path).begin() as conn:
+        conn.execute(stmt)
+
+
+# ---------- transparency log ---------------------------------------------
+
+def translog_append(row: dict, db_path: Path = DB_PATH) -> int:
+    """Append one transparency-log entry. Returns inserted id."""
+    stmt = insert(translog).values(**row)
+    with engine(db_path).begin() as conn:
+        res = conn.execute(stmt)
+        return int(res.inserted_primary_key[0])
+
+
+def translog_head(db_path: Path = DB_PATH) -> Optional[dict]:
+    """Highest-id (latest) entry, or None if chain empty."""
+    stmt = select(translog).order_by(translog.c.id.desc()).limit(1)
+    with engine(db_path).connect() as conn:
+        row = conn.execute(stmt).fetchone()
+    return dict(row._mapping) if row else None
+
+
+def translog_get(entry_id: int, db_path: Path = DB_PATH) -> Optional[dict]:
+    stmt = select(translog).where(translog.c.id == entry_id)
+    with engine(db_path).connect() as conn:
+        row = conn.execute(stmt).fetchone()
+    return dict(row._mapping) if row else None
+
+
+def translog_after(entry_id: int, db_path: Path = DB_PATH) -> List[dict]:
+    """All entries with id > entry_id, oldest first — for sync."""
+    stmt = select(translog).where(translog.c.id > entry_id).order_by(translog.c.id.asc())
+    with engine(db_path).connect() as conn:
+        return [dict(r._mapping) for r in conn.execute(stmt).fetchall()]
+
+
+def translog_recent(limit: int = 100, db_path: Path = DB_PATH) -> List[dict]:
+    stmt = select(translog).order_by(translog.c.id.desc()).limit(limit)
+    with engine(db_path).connect() as conn:
+        return [dict(r._mapping) for r in conn.execute(stmt).fetchall()]
+
+
+def translog_range(start: int = 0, end: Optional[int] = None, db_path: Path = DB_PATH) -> List[dict]:
+    """All entries with start <= id (and id <= end if given), oldest first."""
+    cond = translog.c.id >= start
+    if end is not None:
+        cond = cond & (translog.c.id <= end)
+    stmt = select(translog).where(cond).order_by(translog.c.id.asc())
+    with engine(db_path).connect() as conn:
+        return [dict(r._mapping) for r in conn.execute(stmt).fetchall()]

src/psyc/lines/federation.py

@@ -24,6 +24,7 @@ from cryptography.hazmat.primitives.asymmetric import ed25519
 from pydantic import BaseModel, Field
 
 from psyc import DATA_DIR, db, log
+from psyc.lines import translog
 from psyc.result import Err, Ok, Result
 
 
@@ -259,6 +260,9 @@ def build_signed_feed(window_hours: int = 24) -> Dict[str, Any]:
         "window_hours": window_hours,
         "cases": _build_case_records(window_hours),
         "iocs": _build_ioc_records(window_hours),
+        # Vouches we've issued ride along with the feed so peers can learn
+        # who we trust and accumulate quorum on shared targets.
+        "vouches": [v.model_dump() for v in our_vouches()],
     }
     sig = sign_payload(canonical_json(payload))
     payload["signature"] = base64.b64encode(sig).decode("ascii")
@@ -306,10 +310,16 @@ def import_signed_feed(feed: Dict[str, Any], expected_pubkey_pem: str) -> Result
     except Exception as exc:
         return Err(f"bad pubkey: {exc}")
 
+    # Listening gate: only accept signals from peers we explicitly trust or
+    # that quorum of trusted peers vouches for. Unknown peers don't land here.
+    if not peer_is_listening_eligible(peer_fp):
+        return Err(f"peer not trusted: {peer_fp}")
+
     now = datetime.now(timezone.utc).isoformat()
     signal_ids: List[Tuple[str, str]] = []
     cases = feed.get("cases") or []
     iocs = feed.get("iocs") or []
+    feed_vouches = feed.get("vouches") or []
 
     for c in cases:
         case_id = c.get("case_id") or ""
@@ -323,6 +333,15 @@ def import_signed_feed(feed: Dict[str, Any], expected_pubkey_pem: str) -> Result
             raw_json=json.dumps(c, sort_keys=True),
         ))
         signal_ids.append(("case", digest))
+        try:
+            translog.append("signal", {
+                "peer_fingerprint": peer_fp,
+                "signal_type": "case",
+                "signal_id": case_id,
+                "signal_hash": digest,
+            })
+        except Exception as exc:  # transparency log is best-effort, never block ingest
+            _log.warning("federation.translog.append.fail", error=str(exc))
 
     for i in iocs:
         value = i.get("value") or ""
@@ -336,6 +355,36 @@ def import_signed_feed(feed: Dict[str, Any], expected_pubkey_pem: str) -> Result
             raw_json=json.dumps(i, sort_keys=True),
         ))
         signal_ids.append(("ioc", digest))
+        try:
+            translog.append("signal", {
+                "peer_fingerprint": peer_fp,
+                "signal_type": "ioc",
+                "signal_id": value,
+                "signal_hash": digest,
+            })
+        except Exception as exc:
+            _log.warning("federation.translog.append.fail", error=str(exc))
+
+    # Vouch propagation — peer asserts who they trust. We only accept vouches
+    # whose declared voucher fingerprint matches the peer we just authenticated
+    # (so a peer can't forge vouches "from" someone else through us).
+    for v_raw in feed_vouches:
+        if not isinstance(v_raw, dict):
+            continue
+        try:
+            vouch = Vouch.model_validate(v_raw)
+        except Exception as exc:
+            _log.warning("federation.vouch.malformed", error=str(exc))
+            continue
+        if vouch.voucher_fingerprint != peer_fp:
+            _log.warning(
+                "federation.vouch.voucher_mismatch",
+                claimed=vouch.voucher_fingerprint, actual=peer_fp,
+            )
+            continue
+        accepted = accept_vouch(vouch, expected_pubkey_pem)
+        if isinstance(accepted, Err):
+            _log.warning("federation.vouch.rejected", reason=accepted.reason)
 
     _log.info("federation.import.ok", peer=peer_fp, cases=len(cases), iocs=len(iocs))
     return Ok(ImportSummary(
@@ -403,3 +452,279 @@ def set_peer_status(domain: str, status: str) -> None:
 
 def remove_peer(domain: str) -> None:
     db.remove_peer(domain)
+
+
+# ---------- vouching + quorum (stage 4) ---------------------------------
+#
+# The web of trust: a peer's fingerprint becomes "listening-eligible" when
+# either we directly trust it (peers.status == "trusted") or at least
+# `trust_min_vouchers` of our trusted peers have signed a vouch for it.
+#
+# Signal-level quorum: a federation_signals row is meaningful only when
+# `signal_quorum_k` distinct vouched peers have reported the same signal_hash.
+#
+# Vouches are short Pydantic records signed with the voucher's Ed25519 key
+# over canonical JSON of the body (everything but the signature field).
+
+
+class Vouch(BaseModel):
+    voucher_fingerprint: str
+    target_fingerprint: str
+    issued_at: datetime
+    expires_at: Optional[datetime] = None
+    signature: str = ""  # base64 ed25519 sig over vouch_payload_bytes(...)
+
+
+class QuorumConfig(BaseModel):
+    trust_min_vouchers: int = 2
+    signal_quorum_k: int = 2
+
+
+_QC_TRUST_KEY = "wot_trust_min"
+_QC_K_KEY = "wot_quorum_k"
+
+
+def quorum_config() -> QuorumConfig:
+    """Live quorum settings, with sensible defaults if pulse_settings is empty."""
+    cfg = QuorumConfig()
+    t = db.setting_get(_QC_TRUST_KEY)
+    k = db.setting_get(_QC_K_KEY)
+    if t is not None:
+        try:
+            cfg.trust_min_vouchers = max(1, int(t))
+        except ValueError:
+            pass
+    if k is not None:
+        try:
+            cfg.signal_quorum_k = max(1, int(k))
+        except ValueError:
+            pass
+    return cfg
+
+
+def set_quorum_config(cfg: QuorumConfig) -> None:
+    """Persist quorum config into pulse_settings."""
+    db.setting_set(_QC_TRUST_KEY, str(cfg.trust_min_vouchers))
+    db.setting_set(_QC_K_KEY, str(cfg.signal_quorum_k))
+
+
+def vouch_payload_bytes(
+    voucher_fp: str,
+    target_fp: str,
+    issued_at: datetime,
+    expires_at: Optional[datetime],
+) -> bytes:
+    """Canonical JSON of the unsigned vouch body — what the voucher signs."""
+    body: Dict[str, Any] = {
+        "voucher_fingerprint": voucher_fp,
+        "target_fingerprint": target_fp,
+        "issued_at": issued_at.isoformat(),
+        "expires_at": expires_at.isoformat() if expires_at else None,
+    }
+    return canonical_json(body)
+
+
+def _store_vouch(v: Vouch) -> None:
+    db.upsert_vouch(dict(
+        voucher_fingerprint=v.voucher_fingerprint,
+        target_fingerprint=v.target_fingerprint,
+        issued_at=v.issued_at.isoformat(),
+        expires_at=v.expires_at.isoformat() if v.expires_at else None,
+        signature=v.signature,
+    ))
+
+
+def _row_to_vouch(row: Dict[str, Any]) -> Vouch:
+    return Vouch(
+        voucher_fingerprint=row["voucher_fingerprint"],
+        target_fingerprint=row["target_fingerprint"],
+        issued_at=datetime.fromisoformat(row["issued_at"]),
+        expires_at=datetime.fromisoformat(row["expires_at"]) if row.get("expires_at") else None,
+        signature=row.get("signature") or "",
+    )
+
+
+def issue_vouch(target_fingerprint: str, ttl_days: int = 90) -> Vouch:
+    """Sign a vouch for `target_fingerprint` with OUR key. Persists + returns it."""
+    our_fp = node_fingerprint()
+    issued_at = datetime.now(timezone.utc)
+    expires_at = issued_at + timedelta(days=ttl_days) if ttl_days > 0 else None
+    payload = vouch_payload_bytes(our_fp, target_fingerprint, issued_at, expires_at)
+    sig = sign_payload(payload)
+    vouch = Vouch(
+        voucher_fingerprint=our_fp,
+        target_fingerprint=target_fingerprint,
+        issued_at=issued_at,
+        expires_at=expires_at,
+        signature=base64.b64encode(sig).decode("ascii"),
+    )
+    _store_vouch(vouch)
+    try:
+        translog.append("vouch", {
+            "voucher_fingerprint": vouch.voucher_fingerprint,
+            "target_fingerprint": vouch.target_fingerprint,
+            "issued_at": vouch.issued_at.isoformat(),
+            "expires_at": vouch.expires_at.isoformat() if vouch.expires_at else None,
+        })
+    except Exception as exc:
+        _log.warning("federation.translog.append.fail", error=str(exc))
+    _log.info("federation.vouch.issued", target=target_fingerprint, ttl_days=ttl_days)
+    return vouch
+
+
+def accept_vouch(vouch: Vouch, voucher_pubkey_pem: str) -> Result[None, str]:
+    """Verify signature + expiry + voucher trust status, then persist.
+
+    Failure modes return Err with a short reason so the caller can log them.
+    A voucher whose status is not "trusted" in our peers table is refused —
+    we don't accept transitive vouches from unknown peers.
+    """
+    # Expiry first — cheapest check.
+    now = datetime.now(timezone.utc)
+    if vouch.expires_at is not None and vouch.expires_at < now:
+        return Err("vouch expired")
+
+    # Voucher must be a directly-trusted peer (no transitive trust at this layer).
+    voucher_status = None
+    for row in db.list_peers():
+        if row.get("fingerprint") == vouch.voucher_fingerprint:
+            voucher_status = row.get("status")
+            break
+    if voucher_status != "trusted":
+        return Err(f"voucher not trusted: {vouch.voucher_fingerprint}")
+
+    # The pubkey must match the declared voucher fingerprint.
+    try:
+        if _fingerprint_for_pubkey_pem(voucher_pubkey_pem) != vouch.voucher_fingerprint:
+            return Err("voucher pubkey does not match fingerprint")
+    except Exception as exc:
+        return Err(f"bad voucher pubkey: {exc}")
+
+    payload = vouch_payload_bytes(
+        vouch.voucher_fingerprint,
+        vouch.target_fingerprint,
+        vouch.issued_at,
+        vouch.expires_at,
+    )
+    try:
+        signature = base64.b64decode(vouch.signature)
+    except Exception:
+        return Err("vouch signature not base64")
+    if not verify_payload(payload, signature, voucher_pubkey_pem):
+        return Err("vouch signature invalid")
+
+    _store_vouch(vouch)
+    try:
+        translog.append("vouch", {
+            "voucher_fingerprint": vouch.voucher_fingerprint,
+            "target_fingerprint": vouch.target_fingerprint,
+            "issued_at": vouch.issued_at.isoformat(),
+            "expires_at": vouch.expires_at.isoformat() if vouch.expires_at else None,
+            "accepted": True,
+        })
+    except Exception as exc:
+        _log.warning("federation.translog.append.fail", error=str(exc))
+    _log.info("federation.vouch.accepted", voucher=vouch.voucher_fingerprint, target=vouch.target_fingerprint)
+    return Ok(None)
+
+
+def revoke_vouch(target_fingerprint: str) -> None:
+    """Delete OUR vouch naming `target_fingerprint`. No-op if absent."""
+    db.delete_vouch(node_fingerprint(), target_fingerprint)
+    _log.info("federation.vouch.revoked", target=target_fingerprint)
+
+
+def our_vouches() -> List[Vouch]:
+    """Vouches we have issued (filter for voucher_fingerprint == our fp)."""
+    return [_row_to_vouch(r) for r in db.vouches_by_voucher(node_fingerprint())]
+
+
+def vouches_for(target_fingerprint: str) -> List[Vouch]:
+    """Every vouch stored locally that names `target_fingerprint` as target."""
+    return [_row_to_vouch(r) for r in db.vouches_by_target(target_fingerprint)]
+
+
+def is_vouched(target_fingerprint: str, min_vouchers: Optional[int] = None) -> bool:
+    """True iff ≥`min_vouchers` distinct non-expired vouches from currently-trusted
+    peers name `target_fingerprint`.
+    """
+    cfg = quorum_config()
+    threshold = min_vouchers if min_vouchers is not None else cfg.trust_min_vouchers
+    if threshold <= 0:
+        return True
+    now = datetime.now(timezone.utc)
+    trusted_fps = {p.fingerprint for p in list_peers() if p.status == "trusted"}
+    distinct_vouchers: set = set()
+    for v in vouches_for(target_fingerprint):
+        if v.expires_at is not None and v.expires_at < now:
+            continue
+        if v.voucher_fingerprint not in trusted_fps:
+            continue
+        distinct_vouchers.add(v.voucher_fingerprint)
+        if len(distinct_vouchers) >= threshold:
+            return True
+    return False
+
+
+def peer_is_listening_eligible(fingerprint: str) -> bool:
+    """True iff the peer is directly trusted OR vouched into trust.
+
+    This is the gate used by `import_signed_feed`. Auto-response will share
+    this signature — keep it stable.
+    """
+    if not fingerprint:
+        return False
+    for p in list_peers():
+        if p.fingerprint == fingerprint:
+            if p.status == "trusted":
+                return True
+            if p.status == "blocked":
+                return False
+            break
+    return is_vouched(fingerprint)
+
+
+def is_quorum_met(signal_hash: str, k: Optional[int] = None) -> bool:
+    """True iff ≥k distinct vouched peers have reported `signal_hash`.
+
+    "Vouched" here means `peer_is_listening_eligible` — the same web-of-trust
+    set the import gate respects. Self-reports from the local node do not
+    count (they never end up in federation_signals).
+    """
+    cfg = quorum_config()
+    threshold = k if k is not None else cfg.signal_quorum_k
+    if threshold <= 0:
+        return True
+    rows = db.signals_for_hash(signal_hash)
+    distinct: set = set()
+    for r in rows:
+        fp = r.get("peer_fingerprint") or ""
+        if not fp or fp in distinct:
+            continue
+        if not peer_is_listening_eligible(fp):
+            continue
+        distinct.add(fp)
+        if len(distinct) >= threshold:
+            return True
+    return False
+
+
+def quorum_evidence(signal_hash: str) -> List[Tuple[str, datetime]]:
+    """(peer_fingerprint, received_at) tuples for one signal_hash — for UI display.
+
+    Only includes signals from currently listening-eligible peers, deduped
+    per fingerprint at the earliest receipt.
+    """
+    rows = db.signals_for_hash(signal_hash)
+    earliest: Dict[str, datetime] = {}
+    for r in rows:
+        fp = r.get("peer_fingerprint") or ""
+        if not fp or not peer_is_listening_eligible(fp):
+            continue
+        try:
+            ts = datetime.fromisoformat(r.get("received_at") or "")
+        except ValueError:
+            continue
+        if fp not in earliest or ts < earliest[fp]:
+            earliest[fp] = ts
+    return sorted(earliest.items(), key=lambda kv: kv[1])

src/psyc/lines/translog.py

@@ -0,0 +1,161 @@
+"""Transparency log — append-only signed merkle chain over federation signals.
+
+Every signal we receive from a peer (case, IOC, or accepted vouch) is appended
+as one `LogEntry`. Each entry's `entry_hash = sha256(canonical(prev_hash +
+entry_type + entry_data + timestamp))` references the previous head, so any
+tampering with a historical row invalidates every subsequent hash. The chain
+is public — auditors can re-fetch it and re-run `verify_chain` to detect a
+node that quietly mutated history (e.g. to hide a bad signal it accepted).
+
+Hash format: lowercase hex SHA-256 of the canonical JSON of
+``{"prev_hash": "...", "entry_type": "...", "entry_data": {...}, "timestamp": "..."}``.
+Genesis entries use ``prev_hash = "0" * 64``.
+"""
+
+from __future__ import annotations
+
+import hashlib
+import json
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any, Dict, List, Optional
+
+from pydantic import BaseModel, Field
+
+from psyc import db, log
+from psyc.result import Err, Ok, Result
+
+
+_log = log.get(__name__)
+
+GENESIS_PREV_HASH = "0" * 64
+
+
+class LogEntry(BaseModel):
+    id: int
+    prev_hash: str
+    entry_type: str
+    entry_data: Dict[str, Any] = Field(default_factory=dict)
+    timestamp: str
+    entry_hash: str
+
+
+def _canonical_json(obj: Dict[str, Any]) -> bytes:
+    return json.dumps(obj, sort_keys=True, separators=(",", ":"), ensure_ascii=False).encode("utf-8")
+
+
+def compute_entry_hash(prev_hash: str, entry_type: str, entry_data: Dict[str, Any], timestamp: str) -> str:
+    """Hex SHA-256 of canonical(prev_hash + entry_type + entry_data + timestamp)."""
+    payload: Dict[str, Any] = {
+        "prev_hash": prev_hash,
+        "entry_type": entry_type,
+        "entry_data": entry_data,
+        "timestamp": timestamp,
+    }
+    return hashlib.sha256(_canonical_json(payload)).hexdigest()
+
+
+def _row_to_entry(row: Dict[str, Any]) -> LogEntry:
+    raw = row.get("entry_data") or "{}"
+    try:
+        data = json.loads(raw)
+    except Exception:
+        data = {}
+    return LogEntry(
+        id=int(row["id"]),
+        prev_hash=str(row["prev_hash"]),
+        entry_type=str(row["entry_type"]),
+        entry_data=data if isinstance(data, dict) else {},
+        timestamp=str(row["timestamp"]),
+        entry_hash=str(row["entry_hash"]),
+    )
+
+
+def head(db_path: Path = db.DB_PATH) -> Optional[LogEntry]:
+    """Latest log entry, or None if the chain is empty."""
+    row = db.translog_head(db_path=db_path)
+    return _row_to_entry(row) if row else None
+
+
+def append(entry_type: str, entry_data: Dict[str, Any], db_path: Path = db.DB_PATH) -> LogEntry:
+    """Atomically append one entry to the chain. Returns the persisted entry."""
+    prev = db.translog_head(db_path=db_path)
+    prev_hash = str(prev["entry_hash"]) if prev else GENESIS_PREV_HASH
+    timestamp = datetime.now(timezone.utc).isoformat()
+    entry_hash = compute_entry_hash(prev_hash, entry_type, entry_data, timestamp)
+    new_id = db.translog_append(
+        dict(
+            prev_hash=prev_hash,
+            entry_type=entry_type,
+            entry_data=json.dumps(entry_data, sort_keys=True),
+            timestamp=timestamp,
+            entry_hash=entry_hash,
+        ),
+        db_path=db_path,
+    )
+    _log.info("translog.append", id=new_id, entry_type=entry_type, hash=entry_hash[:12])
+    return LogEntry(
+        id=new_id,
+        prev_hash=prev_hash,
+        entry_type=entry_type,
+        entry_data=entry_data,
+        timestamp=timestamp,
+        entry_hash=entry_hash,
+    )
+
+
+def verify_chain(start: int = 0, end: Optional[int] = None, db_path: Path = db.DB_PATH) -> Result[int, str]:
+    """Walk entries [start, end] in id order, recompute each hash, compare.
+
+    Returns Ok(n_verified) when every entry's recomputed hash equals the
+    stored one and each prev_hash matches the previous entry's stored hash.
+    Returns Err with the offending id + expected/got hashes otherwise.
+    """
+    rows = db.translog_range(start=start, end=end, db_path=db_path)
+    if not rows:
+        return Ok(0)
+    # Establish the prior hash anchor — either genesis (if walking from id=1)
+    # or the entry just before `start`.
+    first_id = int(rows[0]["id"])
+    if first_id <= 1:
+        prior_hash = GENESIS_PREV_HASH
+    else:
+        anchor = db.translog_get(first_id - 1, db_path=db_path)
+        if anchor is None:
+            return Err(f"missing anchor entry id={first_id - 1}")
+        prior_hash = str(anchor["entry_hash"])
+
+    verified = 0
+    for row in rows:
+        stored_prev = str(row["prev_hash"])
+        if stored_prev != prior_hash:
+            return Err(
+                f"broken at id={row['id']} expected_prev={prior_hash} got_prev={stored_prev}"
+            )
+        try:
+            data = json.loads(row.get("entry_data") or "{}")
+        except Exception:
+            return Err(f"broken at id={row['id']} entry_data not JSON")
+        if not isinstance(data, dict):
+            return Err(f"broken at id={row['id']} entry_data not an object")
+        recomputed = compute_entry_hash(
+            stored_prev, str(row["entry_type"]), data, str(row["timestamp"])
+        )
+        stored_hash = str(row["entry_hash"])
+        if recomputed != stored_hash:
+            return Err(
+                f"broken at id={row['id']} expected={recomputed} got={stored_hash}"
+            )
+        prior_hash = stored_hash
+        verified += 1
+    return Ok(verified)
+
+
+def recent(limit: int = 100, db_path: Path = db.DB_PATH) -> List[LogEntry]:
+    """The latest `limit` entries, newest first."""
+    return [_row_to_entry(r) for r in db.translog_recent(limit=limit, db_path=db_path)]
+
+
+def entries_after(entry_id: int, db_path: Path = db.DB_PATH) -> List[LogEntry]:
+    """All entries with id > entry_id, oldest first — for peer sync."""
+    return [_row_to_entry(r) for r in db.translog_after(entry_id, db_path=db_path)]

tests/test_federation.py

@@ -159,6 +159,8 @@ def test_build_then_import_signed_feed_roundtrip(fresh_db, fed_dir):
     new_sig = peer_priv.sign(canonical_json(unsigned))
     feed["signature"] = base64.b64encode(new_sig).decode("ascii")
 
+    # Stage 4 listening gate: peer must be trusted to land signals.
+    federation.register_peer("peer.example", peer_fp, peer_pub_pem, status="trusted")
     result = import_signed_feed(feed, peer_pub_pem)
     assert isinstance(result, Ok), getattr(result, "reason", "")
     summary = result.value

tests/test_translog.py

@@ -0,0 +1,118 @@
+"""Transparency log — append, verify, tamper detection, sync slices."""
+
+from __future__ import annotations
+
+import json
+
+import pytest
+from sqlalchemy import create_engine, update
+
+from psyc import db
+from psyc.lines import translog
+from psyc.lines.translog import GENESIS_PREV_HASH
+from psyc.result import Err, Ok
+
+
+@pytest.fixture
+def fresh_db(tmp_path, monkeypatch):
+    test_db = tmp_path / "test.db"
+    eng = create_engine(f"sqlite:///{test_db}", future=True)
+    db._metadata.create_all(eng, checkfirst=True)
+    monkeypatch.setattr(db, "_engine", eng)
+    monkeypatch.setattr(db, "DB_PATH", test_db)
+    yield test_db
+
+
+def test_first_append_uses_genesis_prev_hash(fresh_db):
+    e = translog.append("signal", {"x": 1})
+    assert e.prev_hash == GENESIS_PREV_HASH
+    assert e.id >= 1
+    assert e.entry_type == "signal"
+    assert e.entry_data == {"x": 1}
+    # head matches
+    h = translog.head()
+    assert h is not None
+    assert h.id == e.id
+    assert h.entry_hash == e.entry_hash
+
+
+def test_append_chains_prev_hash(fresh_db):
+    e1 = translog.append("signal", {"a": 1})
+    e2 = translog.append("signal", {"b": 2})
+    e3 = translog.append("vouch", {"c": 3})
+    assert e2.prev_hash == e1.entry_hash
+    assert e3.prev_hash == e2.entry_hash
+    head = translog.head()
+    assert head is not None
+    assert head.entry_hash == e3.entry_hash
+
+
+def test_verify_chain_ok_round_trip(fresh_db):
+    translog.append("signal", {"a": 1})
+    translog.append("signal", {"b": 2})
+    translog.append("vouch", {"c": 3})
+    result = translog.verify_chain()
+    assert isinstance(result, Ok)
+    assert result.value == 3
+
+
+def test_verify_chain_empty_returns_zero(fresh_db):
+    result = translog.verify_chain()
+    assert isinstance(result, Ok)
+    assert result.value == 0
+
+
+def test_verify_chain_detects_tampered_data(fresh_db):
+    e1 = translog.append("signal", {"a": 1})
+    e2 = translog.append("signal", {"b": 2})
+
+    # Mutate entry_data of the first row directly in the DB; entry_hash stays
+    # the same but no longer matches the recomputed hash.
+    with db.engine().begin() as conn:
+        conn.execute(
+            update(db.translog)
+            .where(db.translog.c.id == e1.id)
+            .values(entry_data=json.dumps({"a": 999}, sort_keys=True))
+        )
+
+    result = translog.verify_chain()
+    assert isinstance(result, Err)
+    assert "broken at id=" in result.reason
+
+
+def test_verify_chain_detects_tampered_prev_hash(fresh_db):
+    translog.append("signal", {"a": 1})
+    e2 = translog.append("signal", {"b": 2})
+    # Flip e2.prev_hash so it no longer matches e1.entry_hash.
+    with db.engine().begin() as conn:
+        conn.execute(
+            update(db.translog)
+            .where(db.translog.c.id == e2.id)
+            .values(prev_hash="f" * 64)
+        )
+    result = translog.verify_chain()
+    assert isinstance(result, Err)
+    assert "broken at id=" in result.reason
+
+
+def test_entries_after_returns_correct_slice(fresh_db):
+    e1 = translog.append("signal", {"a": 1})
+    e2 = translog.append("signal", {"b": 2})
+    e3 = translog.append("signal", {"c": 3})
+
+    after_zero = translog.entries_after(0)
+    assert [e.id for e in after_zero] == [e1.id, e2.id, e3.id]
+
+    after_e1 = translog.entries_after(e1.id)
+    assert [e.id for e in after_e1] == [e2.id, e3.id]
+
+    after_e3 = translog.entries_after(e3.id)
+    assert after_e3 == []
+
+
+def test_recent_newest_first(fresh_db):
+    e1 = translog.append("signal", {"a": 1})
+    e2 = translog.append("signal", {"b": 2})
+    e3 = translog.append("signal", {"c": 3})
+    recent = translog.recent(limit=10)
+    assert [e.id for e in recent] == [e3.id, e2.id, e1.id]

tests/test_vouching.py

@@ -0,0 +1,336 @@
+"""Vouching + quorum — sign/verify, threshold logic, import gate."""
+
+from __future__ import annotations
+
+import base64
+import hashlib
+from datetime import datetime, timedelta, timezone
+
+import pytest
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import ed25519
+from sqlalchemy import create_engine
+
+from psyc import db
+from psyc.lines import federation
+from psyc.lines.federation import (
+    QuorumConfig,
+    Vouch,
+    accept_vouch,
+    build_signed_feed,
+    canonical_json,
+    import_signed_feed,
+    is_quorum_met,
+    is_vouched,
+    issue_vouch,
+    node_fingerprint,
+    our_vouches,
+    peer_is_listening_eligible,
+    public_key_pem,
+    quorum_config,
+    register_peer,
+    revoke_vouch,
+    set_quorum_config,
+    vouch_payload_bytes,
+)
+from psyc.result import Err, Ok
+
+
+@pytest.fixture
+def fresh_db(tmp_path, monkeypatch):
+    test_db = tmp_path / "test.db"
+    eng = create_engine(f"sqlite:///{test_db}", future=True)
+    db._metadata.create_all(eng, checkfirst=True)
+    monkeypatch.setattr(db, "_engine", eng)
+    monkeypatch.setattr(db, "DB_PATH", test_db)
+    yield test_db
+
+
+@pytest.fixture
+def fed_dir(tmp_path, monkeypatch):
+    d = tmp_path / "federation"
+    monkeypatch.setattr(federation, "FED_DIR", d)
+    monkeypatch.setattr(federation, "PRIVATE_KEY_PATH", d / "node.key")
+    monkeypatch.setattr(federation, "PUBLIC_KEY_PATH", d / "node.pub")
+    yield d
+
+
+def _make_peer():
+    """Generate an Ed25519 keypair + matching fingerprint for a fake peer."""
+    priv = ed25519.Ed25519PrivateKey.generate()
+    pub = priv.public_key()
+    pub_pem = pub.public_bytes(
+        encoding=serialization.Encoding.PEM,
+        format=serialization.PublicFormat.SubjectPublicKeyInfo,
+    ).decode("ascii")
+    raw = pub.public_bytes(
+        encoding=serialization.Encoding.Raw,
+        format=serialization.PublicFormat.Raw,
+    )
+    fp = hashlib.sha256(raw).digest()[:16].hex()
+    return priv, pub_pem, fp
+
+
+def _sign_vouch(priv, voucher_fp, target_fp, issued_at, expires_at):
+    payload = vouch_payload_bytes(voucher_fp, target_fp, issued_at, expires_at)
+    sig = priv.sign(payload)
+    return base64.b64encode(sig).decode("ascii")
+
+
+# ---------- self-issued vouch round-trip --------------------------------
+
+def test_issue_vouch_roundtrip(fresh_db, fed_dir):
+    target = "ab" * 16
+    v = issue_vouch(target, ttl_days=30)
+    assert v.voucher_fingerprint == node_fingerprint()
+    assert v.target_fingerprint == target
+    assert v.expires_at is not None
+    # round-trip from storage
+    listed = our_vouches()
+    assert len(listed) == 1
+    assert listed[0].target_fingerprint == target
+    assert listed[0].signature == v.signature
+    # signature verifies under our own pubkey
+    payload = vouch_payload_bytes(
+        v.voucher_fingerprint, v.target_fingerprint, v.issued_at, v.expires_at
+    )
+    sig = base64.b64decode(v.signature)
+    assert federation.verify_payload(payload, sig, public_key_pem())
+
+
+def test_revoke_vouch_removes_only_our_entry(fresh_db, fed_dir):
+    target = "cd" * 16
+    issue_vouch(target, ttl_days=30)
+    assert len(our_vouches()) == 1
+    revoke_vouch(target)
+    assert our_vouches() == []
+
+
+# ---------- accept_vouch validation -------------------------------------
+
+def test_accept_vouch_rejects_expired(fresh_db, fed_dir):
+    priv, pem, fp = _make_peer()
+    register_peer("voucher.example", fp, pem, status="trusted")
+    issued = datetime.now(timezone.utc) - timedelta(days=10)
+    expired = datetime.now(timezone.utc) - timedelta(days=1)
+    sig = _sign_vouch(priv, fp, "target", issued, expired)
+    v = Vouch(voucher_fingerprint=fp, target_fingerprint="target",
+              issued_at=issued, expires_at=expired, signature=sig)
+    result = accept_vouch(v, pem)
+    assert isinstance(result, Err)
+    assert "expired" in result.reason
+
+
+def test_accept_vouch_rejects_bad_signature(fresh_db, fed_dir):
+    priv, pem, fp = _make_peer()
+    register_peer("voucher.example", fp, pem, status="trusted")
+    issued = datetime.now(timezone.utc)
+    expires = issued + timedelta(days=30)
+    # Sign a different target then claim it's for "real-target".
+    real_sig = _sign_vouch(priv, fp, "other-target", issued, expires)
+    v = Vouch(voucher_fingerprint=fp, target_fingerprint="real-target",
+              issued_at=issued, expires_at=expires, signature=real_sig)
+    result = accept_vouch(v, pem)
+    assert isinstance(result, Err)
+    assert "signature" in result.reason
+
+
+def test_accept_vouch_rejects_voucher_not_trusted(fresh_db, fed_dir):
+    priv, pem, fp = _make_peer()
+    # Voucher exists but is "unknown" not "trusted".
+    register_peer("voucher.example", fp, pem, status="unknown")
+    issued = datetime.now(timezone.utc)
+    expires = issued + timedelta(days=30)
+    sig = _sign_vouch(priv, fp, "target", issued, expires)
+    v = Vouch(voucher_fingerprint=fp, target_fingerprint="target",
+              issued_at=issued, expires_at=expires, signature=sig)
+    result = accept_vouch(v, pem)
+    assert isinstance(result, Err)
+    assert "not trusted" in result.reason
+
+
+def test_accept_vouch_ok_for_trusted_voucher(fresh_db, fed_dir):
+    priv, pem, fp = _make_peer()
+    register_peer("voucher.example", fp, pem, status="trusted")
+    issued = datetime.now(timezone.utc)
+    expires = issued + timedelta(days=30)
+    sig = _sign_vouch(priv, fp, "target", issued, expires)
+    v = Vouch(voucher_fingerprint=fp, target_fingerprint="target",
+              issued_at=issued, expires_at=expires, signature=sig)
+    result = accept_vouch(v, pem)
+    assert isinstance(result, Ok)
+
+
+# ---------- is_vouched threshold ----------------------------------------
+
+def test_is_vouched_needs_distinct_vouchers(fresh_db, fed_dir):
+    """Two vouches from the same peer must NOT clear a threshold of 2."""
+    priv, pem, fp = _make_peer()
+    register_peer("voucher.example", fp, pem, status="trusted")
+
+    issued = datetime.now(timezone.utc)
+    expires = issued + timedelta(days=30)
+    sig = _sign_vouch(priv, fp, "target", issued, expires)
+    v1 = Vouch(voucher_fingerprint=fp, target_fingerprint="target",
+               issued_at=issued, expires_at=expires, signature=sig)
+    assert isinstance(accept_vouch(v1, pem), Ok)
+
+    # Newer vouch from the SAME voucher — upsert replaces, count stays 1.
+    issued2 = issued + timedelta(seconds=1)
+    sig2 = _sign_vouch(priv, fp, "target", issued2, expires)
+    v2 = Vouch(voucher_fingerprint=fp, target_fingerprint="target",
+               issued_at=issued2, expires_at=expires, signature=sig2)
+    assert isinstance(accept_vouch(v2, pem), Ok)
+
+    assert is_vouched("target", min_vouchers=2) is False
+    # Threshold of 1 should pass.
+    assert is_vouched("target", min_vouchers=1) is True
+
+
+def test_is_vouched_two_distinct_clear_threshold(fresh_db, fed_dir):
+    priv_a, pem_a, fp_a = _make_peer()
+    priv_b, pem_b, fp_b = _make_peer()
+    register_peer("a.example", fp_a, pem_a, status="trusted")
+    register_peer("b.example", fp_b, pem_b, status="trusted")
+
+    issued = datetime.now(timezone.utc)
+    expires = issued + timedelta(days=30)
+    va = Vouch(voucher_fingerprint=fp_a, target_fingerprint="target",
+               issued_at=issued, expires_at=expires,
+               signature=_sign_vouch(priv_a, fp_a, "target", issued, expires))
+    vb = Vouch(voucher_fingerprint=fp_b, target_fingerprint="target",
+               issued_at=issued, expires_at=expires,
+               signature=_sign_vouch(priv_b, fp_b, "target", issued, expires))
+    assert isinstance(accept_vouch(va, pem_a), Ok)
+    assert isinstance(accept_vouch(vb, pem_b), Ok)
+
+    assert is_vouched("target", min_vouchers=2) is True
+    assert is_vouched("target", min_vouchers=3) is False
+
+
+# ---------- quorum on signal_hash ---------------------------------------
+
+def test_is_quorum_met_counts_distinct_vouched_peers_only(fresh_db, fed_dir):
+    # Two trusted peers + one untrusted peer report the same signal_hash.
+    _, pem_a, fp_a = _make_peer()
+    _, pem_b, fp_b = _make_peer()
+    _, pem_c, fp_c = _make_peer()
+    register_peer("a.example", fp_a, pem_a, status="trusted")
+    register_peer("b.example", fp_b, pem_b, status="trusted")
+    register_peer("c.example", fp_c, pem_c, status="unknown")  # not eligible
+
+    for fp in (fp_a, fp_b, fp_c, fp_a):  # fp_a duplicated → still 1 distinct
+        db.record_signal(dict(
+            peer_fingerprint=fp,
+            signal_type="ioc",
+            signal_id="1.2.3.4",
+            signal_hash="h-aaa",
+            received_at=datetime.now(timezone.utc).isoformat(),
+            raw_json="{}",
+        ))
+
+    assert is_quorum_met("h-aaa", k=2) is True
+    assert is_quorum_met("h-aaa", k=3) is False  # only 2 eligible distincts
+
+
+# ---------- quorum config persistence -----------------------------------
+
+def test_quorum_config_defaults_and_persistence(fresh_db, fed_dir):
+    cfg = quorum_config()
+    assert cfg.trust_min_vouchers == 2
+    assert cfg.signal_quorum_k == 2
+    set_quorum_config(QuorumConfig(trust_min_vouchers=3, signal_quorum_k=4))
+    cfg2 = quorum_config()
+    assert cfg2.trust_min_vouchers == 3
+    assert cfg2.signal_quorum_k == 4
+
+
+# ---------- import gate enforces listening eligibility ------------------
+
+def _signed_feed_from_peer(peer_priv, peer_fp, vouches=None):
+    """Build a feed claiming origin=peer_fp, signed with peer_priv."""
+    payload = {
+        "version": federation.FEED_VERSION,
+        "fingerprint": peer_fp,
+        "generated_at": datetime.now(timezone.utc).isoformat(),
+        "window_hours": 24,
+        "cases": [],
+        "iocs": [{
+            "value": "9.9.9.9",
+            "type": "ip",
+            "severity": "high",
+            "first_seen": datetime.now(timezone.utc).isoformat(),
+            "digest_sha256": "abc123",
+        }],
+        "vouches": vouches or [],
+    }
+    sig = peer_priv.sign(canonical_json(payload))
+    payload["signature"] = base64.b64encode(sig).decode("ascii")
+    return payload
+
+
+def test_import_feed_rejects_unknown_peer(fresh_db, fed_dir):
+    peer_priv, peer_pem, peer_fp = _make_peer()
+    feed = _signed_feed_from_peer(peer_priv, peer_fp)
+    result = import_signed_feed(feed, peer_pem)
+    assert isinstance(result, Err)
+    assert "not trusted" in result.reason
+
+
+def test_import_feed_accepts_directly_trusted_peer(fresh_db, fed_dir):
+    peer_priv, peer_pem, peer_fp = _make_peer()
+    register_peer("peer.example", peer_fp, peer_pem, status="trusted")
+    feed = _signed_feed_from_peer(peer_priv, peer_fp)
+    result = import_signed_feed(feed, peer_pem)
+    assert isinstance(result, Ok), getattr(result, "reason", "")
+
+
+def test_import_feed_accepts_vouched_peer(fresh_db, fed_dir):
+    # Two trusted peers vouch for a third — third becomes listening-eligible.
+    priv_a, pem_a, fp_a = _make_peer()
+    priv_b, pem_b, fp_b = _make_peer()
+    priv_c, pem_c, fp_c = _make_peer()
+    register_peer("a.example", fp_a, pem_a, status="trusted")
+    register_peer("b.example", fp_b, pem_b, status="trusted")
+
+    issued = datetime.now(timezone.utc)
+    expires = issued + timedelta(days=30)
+    va = Vouch(voucher_fingerprint=fp_a, target_fingerprint=fp_c,
+               issued_at=issued, expires_at=expires,
+               signature=_sign_vouch(priv_a, fp_a, fp_c, issued, expires))
+    vb = Vouch(voucher_fingerprint=fp_b, target_fingerprint=fp_c,
+               issued_at=issued, expires_at=expires,
+               signature=_sign_vouch(priv_b, fp_b, fp_c, issued, expires))
+    assert isinstance(accept_vouch(va, pem_a), Ok)
+    assert isinstance(accept_vouch(vb, pem_b), Ok)
+    assert peer_is_listening_eligible(fp_c) is True
+
+    feed = _signed_feed_from_peer(priv_c, fp_c)
+    result = import_signed_feed(feed, pem_c)
+    assert isinstance(result, Ok), getattr(result, "reason", "")
+
+
+def test_import_feed_propagates_vouches_in_payload(fresh_db, fed_dir):
+    """A trusted peer's feed carries a vouch the peer issued — we should
+    accept_vouch it and store it locally."""
+    peer_priv, peer_pem, peer_fp = _make_peer()
+    register_peer("peer.example", peer_fp, peer_pem, status="trusted")
+
+    target_fp = "ff" * 16
+    issued = datetime.now(timezone.utc)
+    expires = issued + timedelta(days=30)
+    peer_vouch = Vouch(
+        voucher_fingerprint=peer_fp,
+        target_fingerprint=target_fp,
+        issued_at=issued,
+        expires_at=expires,
+        signature=_sign_vouch(peer_priv, peer_fp, target_fp, issued, expires),
+    )
+    feed = _signed_feed_from_peer(peer_priv, peer_fp, vouches=[peer_vouch.model_dump(mode="json")])
+
+    result = import_signed_feed(feed, peer_pem)
+    assert isinstance(result, Ok), getattr(result, "reason", "")
+
+    # The vouch is now in our local store under the peer's fingerprint.
+    stored = federation.vouches_for(target_fp)
+    assert any(v.voucher_fingerprint == peer_fp for v in stored)