diff --git a/docs/eve-migration-roadmap.md b/docs/eve-migration-roadmap.md
index e040c8f..f6ea6f9 100644
--- a/docs/eve-migration-roadmap.md
+++ b/docs/eve-migration-roadmap.md
@@ -280,6 +280,11 @@ Exit criteria:
 
 Recently cut:
 
+- Sai, Norn, and TeX plugin ABI fixtures now cover `lower` and `measure` in
+  addition to `describe`, `validate`, `project`, and `apply`. Eve validates the
+  operation shape, preserved component kinds, measurement outputs, and provider
+  authority flag without importing plugin internals or deciding plugin
+  semantics.
 - The web reference now publishes a runtime capability manifest at
   `web/eve-runtime-capability.json`, and the parity harness validates it through
   the same runtime capability path as Unity. Web remains Eve's behavior oracle,
@@ -354,9 +359,9 @@ Recently cut:
   command boundary consumption, command intents, and provider-owned receipt
   states without importing Aetheria internals into Eve.
 - Sai, Norn, and TeX now have plugin ABI fixtures for describe, validate,
-  project, and apply behavior. The parity harness validates those fixtures
-  against plugin manifests, so Eve proves the ABI shape without owning plugin
-  semantics.
+  project, lower, measure, and apply behavior. The parity harness validates
+  those fixtures against plugin manifests, so Eve proves the ABI shape without
+  owning plugin semantics.
 - Split-readiness reporting now exists for `EveFlutter` and `EveUnity`. The
   parity report lists member runtime health, required plugin capability claims,
   pending proofs, and blockers before either repo can graduate out of Eve
diff --git a/docs/plugin-architecture.md b/docs/plugin-architecture.md
index 477ee6e..c50a0d2 100644
--- a/docs/plugin-architecture.md
+++ b/docs/plugin-architecture.md
@@ -573,8 +573,8 @@ For Sai VN:
 - embedded surface slot fixture with optional Norn/TeX plugin dependencies;
 - degraded renderer fixture for clients without scene placement;
 - receipt round-trip fixture driven by a fake provider.
-- ABI fixture proving `validate`, `apply`, and `project` produce the expected
-  plugin results without direct imports.
+- ABI fixture proving `describe`, `validate`, `project`, `lower`, `measure`,
+  and `apply` publish the expected contract shape without direct imports.
 
 The parity manifest should be extended so runtimes declare plugin support:
 
diff --git a/plugins/incubating/norn-graph.plugin-abi-fixture.json b/plugins/incubating/norn-graph.plugin-abi-fixture.json
index a68fe76..2abf092 100644
--- a/plugins/incubating/norn-graph.plugin-abi-fixture.json
+++ b/plugins/incubating/norn-graph.plugin-abi-fixture.json
@@ -43,6 +43,32 @@
         "outputSchemas": ["norn.graph.document.v1", "norn.graph.layout_request.v1", "norn.graph.layout_result.v1"]
       }
     },
+    {
+      "operation": "lower",
+      "input": {
+        "projection": "embedded-semantic-surface",
+        "targetRuntimes": ["web", "unity-uitoolkit"],
+        "componentKinds": ["embed.norn"]
+      },
+      "expect": {
+        "loweringKind": "graph-viewport",
+        "preservedComponentKinds": ["embed.norn"],
+        "requiredSchemas": ["norn.graph.document.v1", "norn.graph.layout_result.v1"],
+        "commandEnvelope": "gamecult.eve.command.v1"
+      }
+    },
+    {
+      "operation": "measure",
+      "input": {
+        "projection": "embedded-semantic-surface",
+        "layoutRequestSchema": "norn.graph.layout_request.v1"
+      },
+      "expect": {
+        "measurementKind": "graph-layout-metrics",
+        "measurementOutputs": ["nodeBounds", "edgeRoutes", "viewportBounds"],
+        "preservesProviderAuthority": true
+      }
+    },
     {
       "operation": "apply",
       "input": {
diff --git a/plugins/incubating/sai-vn.plugin-abi-fixture.json b/plugins/incubating/sai-vn.plugin-abi-fixture.json
index ec53db2..6fc535a 100644
--- a/plugins/incubating/sai-vn.plugin-abi-fixture.json
+++ b/plugins/incubating/sai-vn.plugin-abi-fixture.json
@@ -43,6 +43,32 @@
         "delegatedPlugins": ["norn.graph", "tex.math"]
       }
     },
+    {
+      "operation": "lower",
+      "input": {
+        "projection": "semantic-surface",
+        "targetRuntimes": ["web", "unity-uitoolkit"],
+        "componentKinds": ["vn.stage", "panel.dialogue", "text.dialogue", "rail.actions"]
+      },
+      "expect": {
+        "loweringKind": "runtime-neutral-stage-parts",
+        "preservedComponentKinds": ["vn.stage", "panel.dialogue", "text.dialogue", "rail.actions"],
+        "delegatedPlugins": ["norn.graph", "tex.math"],
+        "commandEnvelope": "gamecult.eve.command.v1"
+      }
+    },
+    {
+      "operation": "measure",
+      "input": {
+        "projection": "semantic-surface",
+        "placementKinds": ["overlay", "keystone", "sprite-chromakey"]
+      },
+      "expect": {
+        "measurementKind": "scene-placement-hints",
+        "measurementOutputs": ["preferredBounds", "safeTextRegion", "embeddedSurfaceSlots"],
+        "preservesProviderAuthority": true
+      }
+    },
     {
       "operation": "apply",
       "input": {
diff --git a/plugins/incubating/sai-vn.plugin.json b/plugins/incubating/sai-vn.plugin.json
index fa5da50..9a75c6e 100644
--- a/plugins/incubating/sai-vn.plugin.json
+++ b/plugins/incubating/sai-vn.plugin.json
@@ -7,7 +7,7 @@
     "ownerRepo": "Sai",
     "currentHostRepo": "Eve",
     "splitTarget": "Sai/sai-vn-plugin",
-    "graduationTrigger": "Split when VN/Ink semantics, story command fixtures, and ABI validate/apply/project cases are stable."
+    "graduationTrigger": "Split when VN/Ink semantics, story command fixtures, and ABI describe/validate/project/lower/measure/apply cases are stable."
   },
   "componentKinds": [
     "vn.stage",
diff --git a/plugins/incubating/tex-math.plugin-abi-fixture.json b/plugins/incubating/tex-math.plugin-abi-fixture.json
index 5ed753a..b6e2939 100644
--- a/plugins/incubating/tex-math.plugin-abi-fixture.json
+++ b/plugins/incubating/tex-math.plugin-abi-fixture.json
@@ -43,6 +43,32 @@
         "outputSchemas": ["tex.math.render_request.v1", "tex.math.render_result.v1"]
       }
     },
+    {
+      "operation": "lower",
+      "input": {
+        "projection": "render-request",
+        "targetRuntimes": ["web"],
+        "componentKinds": ["embed.tex"]
+      },
+      "expect": {
+        "loweringKind": "typeset-fragment",
+        "preservedComponentKinds": ["embed.tex"],
+        "requiredSchemas": ["tex.math.render_request.v1", "tex.math.render_result.v1"],
+        "fallbackKind": "source-text"
+      }
+    },
+    {
+      "operation": "measure",
+      "input": {
+        "projection": "render-request",
+        "sourceSchema": "tex.math.source.v1"
+      },
+      "expect": {
+        "measurementKind": "typeset-baseline-metrics",
+        "measurementOutputs": ["baseline", "advance", "inkBounds", "fallbackBounds"],
+        "preservesProviderAuthority": true
+      }
+    },
     {
       "operation": "apply",
       "input": {
diff --git a/tools/parity/run-parity.mjs b/tools/parity/run-parity.mjs
index fd95745..847c2d7 100644
--- a/tools/parity/run-parity.mjs
+++ b/tools/parity/run-parity.mjs
@@ -375,6 +375,7 @@ async function evaluatePlugin(plugin, fixtureResults) {
     schema: "gamecult.eve.plugin_advertisement.v1",
     pluginId: plugin.pluginId,
   });
+  const abiOperations = await readPluginAbiOperations(plugin.abiFixturePath);
   const abiErrors = await validatePluginAbiFixture(plugin);
   const status = missingPaths.length
     ? "missing-body"
@@ -407,6 +408,7 @@ async function evaluatePlugin(plugin, fixtureResults) {
     schemaPath: plugin.schemaPath || "",
     manifestPath: plugin.manifestPath || "",
     abiFixturePath: plugin.abiFixturePath || "",
+    abiOperations,
     advertisementSchemaPath: plugin.advertisementSchemaPath || "",
     advertisementPath: plugin.advertisementPath || "",
     schemaErrors,
@@ -419,6 +421,19 @@ async function evaluatePlugin(plugin, fixtureResults) {
   };
 }
 
+async function readPluginAbiOperations(abiFixturePath) {
+  if (!abiFixturePath) return [];
+  try {
+    const abiFixture = await readJsonDocument(abiFixturePath);
+    return (abiFixture.operations || [])
+      .map(operation => operation.operation)
+      .filter(Boolean)
+      .sort();
+  } catch {
+    return [];
+  }
+}
+
 async function evaluateFixtureMetadata(fixture) {
   const errors = [];
   if (!fixture.metadataPath) return { metadata: null, errors: ["metadataPath:missing"] };
@@ -616,7 +631,7 @@ async function validatePluginAbiFixture(plugin) {
       errors.push(`${plugin.abiFixturePath}:contract:expected gamecult.eve.plugin_abi.v1 got ${abiFixture.contract}`);
     }
 
-    for (const operation of ["describe", "validate", "project", "apply"]) {
+    for (const operation of ["describe", "validate", "project", "lower", "measure", "apply"]) {
       if (!operations.has(operation)) errors.push(`${plugin.abiFixturePath}:operation:${operation}:missing`);
     }
 
@@ -643,6 +658,15 @@ async function validatePluginAbiFixture(plugin) {
     errors.push(...missingMembers(manifestComponentKinds, project.ownedComponentKinds || [], `${plugin.abiFixturePath}:project.ownedComponentKinds`));
     if (!project.projectionKind) errors.push(`${plugin.abiFixturePath}:project.projectionKind:missing`);
 
+    const lower = operations.get("lower")?.expect || {};
+    errors.push(...missingMembers(manifestComponentKinds, lower.preservedComponentKinds || [], `${plugin.abiFixturePath}:lower.preservedComponentKinds`));
+    if (!lower.loweringKind) errors.push(`${plugin.abiFixturePath}:lower.loweringKind:missing`);
+
+    const measure = operations.get("measure")?.expect || {};
+    if (!measure.measurementKind) errors.push(`${plugin.abiFixturePath}:measure.measurementKind:missing`);
+    if (!(measure.measurementOutputs || []).length) errors.push(`${plugin.abiFixturePath}:measure.measurementOutputs:missing`);
+    if (measure.preservesProviderAuthority !== true) errors.push(`${plugin.abiFixturePath}:measure.preservesProviderAuthority:expected true`);
+
     const apply = operations.get("apply")?.expect || {};
     if (manifestCommands.length) {
       const commandEffects = apply.commandEffects || {};
@@ -1181,6 +1205,7 @@ function buildConformanceExport(report) {
       status: plugin.status,
       ownerRepo: plugin.ownerRepo,
       abiFixturePath: plugin.abiFixturePath,
+      abiOperations: plugin.abiOperations || [],
       capabilities: plugin.capabilities,
     })),
     providers: (report.providers || []).map(provider => ({
@@ -1323,7 +1348,7 @@ function renderMarkdown(report) {
     lines.push(`| ${fixture.title} | ${fixture.metadataPath} | ${fixture.metadata?.purpose || ""} | ${fixture.metadataErrors.join(", ")} |`);
   }
 
-  lines.push("", "## Plugins", "", "| Plugin | Status | Owner | ABI Fixture | Capabilities | Missing |", "| --- | --- | --- | --- | --- | --- |");
+  lines.push("", "## Plugins", "", "| Plugin | Status | Owner | ABI Operations | ABI Fixture | Capabilities | Missing |", "| --- | --- | --- | --- | --- | --- | --- |");
   for (const plugin of report.plugins || []) {
     const missing = [
       ...plugin.missingPaths,
@@ -1333,7 +1358,7 @@ function renderMarkdown(report) {
       ...plugin.advertisementErrors.map(id => `advertisement:${id}`),
       ...plugin.abiErrors.map(id => `abi:${id}`),
     ].join(", ");
-    lines.push(`| ${plugin.title || plugin.pluginId} | ${plugin.status} | ${plugin.ownerRepo} | ${plugin.abiFixturePath || ""} | ${plugin.capabilities.join(", ")} | ${missing} |`);
+    lines.push(`| ${plugin.title || plugin.pluginId} | ${plugin.status} | ${plugin.ownerRepo} | ${(plugin.abiOperations || []).join(", ")} | ${plugin.abiFixturePath || ""} | ${plugin.capabilities.join(", ")} | ${missing} |`);
   }
 
   lines.push("", "## Providers", "", "| Provider | Status | Owner | Scenario | Receipt States | Surfaces | Commands | Witnesses | Missing |", "| --- | --- | --- | --- | --- | --- | --- | --- | --- |");