diff --git a/docs/adr/0001-sourceos-shell-boundary.md b/docs/adr/0001-sourceos-shell-boundary.md
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+++ b/docs/adr/0001-sourceos-shell-boundary.md
@@ -0,0 +1,35 @@
+# ADR 0001 — sourceos-shell contract boundary
+
+## Status
+Accepted
+
+## Context
+
+The SourceOS shell work introduces a product/runtime surface for:
+
+- Markdown-first authoring
+- PDF derivation, signing, and validation
+- search routing decisions
+- comment/review signal surfaces
+- annotation export
+- run reports and Noether diagnostics
+- publish and mirror receipts
+
+These objects are exchanged across product code, Linux realization, and publishing/provenance systems. They should not be defined ad hoc inside runtime repositories.
+
+## Decision
+
+The repository split is:
+
+- `SourceOS-Linux/sourceos-shell` — product/runtime code
+- `SourceOS-Linux/sourceos-spec` — shared machine-readable contracts
+- `SociOS-Linux/source-os` — Linux realization surfaces
+- `SociOS-Linux/albert` — temporary launcher bridge only
+
+The canonical object shapes for shell/document/provenance/search/report flows are defined here in `sourceos-spec`.
+
+## Consequences
+
+- shell/runtime code consumes generated types from this repository
+- Linux realization refers back to these contracts instead of redefining them
+- publish, mirror, validation, and routing receipts become interoperable across implementations
diff --git a/examples/artifact-manifest.json b/examples/artifact-manifest.json
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+++ b/examples/artifact-manifest.json
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+{
+  "artifactId": "demo-report",
+  "source": {
+    "path": "content/draft/demo-report.md",
+    "commit": "deadbeef"
+  },
+  "unsignedPdf": "content/derived/pdf/demo-report.pdf",
+  "signedPdf": "content/derived/pdf_signed/demo-report.signed.pdf",
+  "sha256": "0123cafe0123cafe0123cafe0123cafe",
+  "signed": true,
+  "pdfa": true,
+  "signer": "CN=Docs PSigner",
+  "signature": {
+    "type": "PKCS#7",
+    "issuer": "CN=Docs PSigner"
+  }
+}
diff --git a/examples/comment-signal.json b/examples/comment-signal.json
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--- /dev/null
+++ b/examples/comment-signal.json
@@ -0,0 +1,7 @@
+{
+  "commentId": "comment-123",
+  "genuineProb": 0.83,
+  "sarcasmProb": 0.12,
+  "experience": "experienced",
+  "verified": true
+}
diff --git a/examples/pdf-validation-report.json b/examples/pdf-validation-report.json
new file mode 100644
index 0000000..c9bfa33
--- /dev/null
+++ b/examples/pdf-validation-report.json
@@ -0,0 +1,12 @@
+{
+  "artifactId": "demo-report",
+  "validatedAt": "2026-04-16T22:05:00Z",
+  "pdfcpu": {
+    "ok": true,
+    "checks": ["xref", "metadata", "page-tree"]
+  },
+  "verapdf": {
+    "ok": true,
+    "flavour": "PDF/A-2b"
+  }
+}
diff --git a/examples/search-route-decision.json b/examples/search-route-decision.json
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--- /dev/null
+++ b/examples/search-route-decision.json
@@ -0,0 +1,7 @@
+{
+  "scope": "files",
+  "provider": "linux_files",
+  "query": "report.pdf",
+  "routedAt": "2026-04-16T22:10:00Z",
+  "redundantSearchPrevented": true
+}
diff --git a/examples/signed-artifact.json b/examples/signed-artifact.json
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--- /dev/null
+++ b/examples/signed-artifact.json
@@ -0,0 +1,8 @@
+{
+  "artifactId": "demo-report",
+  "signer": "CN=Docs PSigner",
+  "algorithm": "PKCS#7",
+  "timestamp": "2026-04-16T22:00:00Z",
+  "issuer": "CN=Docs PSigner",
+  "signatureRef": "content/derived/pdf_signed/demo-report.signed.pdf"
+}
diff --git a/schemas/ArtifactManifest.json b/schemas/ArtifactManifest.json
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+++ b/schemas/ArtifactManifest.json
@@ -0,0 +1,27 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "urn:srcos:schema:ArtifactManifest",
+  "title": "ArtifactManifest",
+  "type": "object",
+  "required": ["artifactId", "source", "unsignedPdf", "sha256", "signed", "pdfa"],
+  "properties": {
+    "artifactId": {"type": "string"},
+    "source": {
+      "type": "object",
+      "required": ["path", "commit"],
+      "properties": {
+        "path": {"type": "string"},
+        "commit": {"type": "string"}
+      },
+      "additionalProperties": false
+    },
+    "unsignedPdf": {"type": "string"},
+    "signedPdf": {"type": ["string", "null"]},
+    "sha256": {"type": "string"},
+    "signed": {"type": "boolean"},
+    "pdfa": {"type": "boolean"},
+    "signer": {"type": ["string", "null"]},
+    "signature": {"type": ["object", "null"]}
+  },
+  "additionalProperties": false
+}
diff --git a/schemas/CommentSignal.json b/schemas/CommentSignal.json
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--- /dev/null
+++ b/schemas/CommentSignal.json
@@ -0,0 +1,15 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "urn:srcos:schema:CommentSignal",
+  "title": "CommentSignal",
+  "type": "object",
+  "required": ["commentId", "genuineProb", "sarcasmProb", "experience"],
+  "properties": {
+    "commentId": {"type": "string"},
+    "genuineProb": {"type": "number", "minimum": 0, "maximum": 1},
+    "sarcasmProb": {"type": "number", "minimum": 0, "maximum": 1},
+    "experience": {"type": "string", "enum": ["new", "experienced"]},
+    "verified": {"type": ["boolean", "null"]}
+  },
+  "additionalProperties": false
+}
diff --git a/schemas/PdfValidationReport.json b/schemas/PdfValidationReport.json
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--- /dev/null
+++ b/schemas/PdfValidationReport.json
@@ -0,0 +1,30 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "urn:srcos:schema:PdfValidationReport",
+  "title": "PdfValidationReport",
+  "type": "object",
+  "required": ["artifactId", "validatedAt", "pdfcpu", "verapdf"],
+  "properties": {
+    "artifactId": {"type": "string"},
+    "validatedAt": {"type": "string", "format": "date-time"},
+    "pdfcpu": {
+      "type": "object",
+      "required": ["ok"],
+      "properties": {
+        "ok": {"type": "boolean"},
+        "checks": {"type": "array", "items": {"type": "string"}}
+      },
+      "additionalProperties": true
+    },
+    "verapdf": {
+      "type": "object",
+      "required": ["ok"],
+      "properties": {
+        "ok": {"type": "boolean"},
+        "flavour": {"type": ["string", "null"]}
+      },
+      "additionalProperties": true
+    }
+  },
+  "additionalProperties": false
+}
diff --git a/schemas/SearchRouteDecision.json b/schemas/SearchRouteDecision.json
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--- /dev/null
+++ b/schemas/SearchRouteDecision.json
@@ -0,0 +1,15 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "urn:srcos:schema:SearchRouteDecision",
+  "title": "SearchRouteDecision",
+  "type": "object",
+  "required": ["scope", "provider", "query"],
+  "properties": {
+    "scope": {"type": "string", "enum": ["apps", "files", "web"]},
+    "provider": {"type": "string"},
+    "query": {"type": "string"},
+    "routedAt": {"type": ["string", "null"], "format": "date-time"},
+    "redundantSearchPrevented": {"type": ["boolean", "null"]}
+  },
+  "additionalProperties": false
+}
diff --git a/schemas/SignedArtifact.json b/schemas/SignedArtifact.json
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index 0000000..3fef384
--- /dev/null
+++ b/schemas/SignedArtifact.json
@@ -0,0 +1,16 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "urn:srcos:schema:SignedArtifact",
+  "title": "SignedArtifact",
+  "type": "object",
+  "required": ["artifactId", "signer", "algorithm", "timestamp"],
+  "properties": {
+    "artifactId": {"type": "string"},
+    "signer": {"type": "string"},
+    "algorithm": {"type": "string"},
+    "timestamp": {"type": "string", "format": "date-time"},
+    "issuer": {"type": ["string", "null"]},
+    "signatureRef": {"type": ["string", "null"]}
+  },
+  "additionalProperties": false
+}