diff --git a/.changeset/lint-missing-config-envelope-invalid.md b/.changeset/lint-missing-config-envelope-invalid.md
new file mode 100644
index 0000000..f5fc9ab
--- /dev/null
+++ b/.changeset/lint-missing-config-envelope-invalid.md
@@ -0,0 +1,12 @@
+---
+'@ai-plugin-marketplace/core': patch
+---
+
+Fix `aipm lint` staying silent for a plugin whose `aipm.config.ts` cannot be resolved — cases
+`aipm validate` (hard `envelope-invalid`) and `aipm build` (thrown `ConfigLoadError`) already
+caught. The `schema/envelope-shape` rule now fires for every envelope-load failure, not only a
+schema violation: a plugin-shaped directory missing `aipm.config.ts`, and a config file that is
+present but cannot be imported (syntax error, no usable default export). Both emit the same
+`envelope-invalid`-backed, `error`-severity diagnostic `validate` reports for the identical tree,
+carrying the config loader's own message verbatim, so the three surfaces agree instead of `lint`
+reporting a clean bill of health for a broken plugin.
diff --git a/docs/specs/lint-engine.md b/docs/specs/lint-engine.md
index e8aebf6..6d8e5e3 100644
--- a/docs/specs/lint-engine.md
+++ b/docs/specs/lint-engine.md
@@ -213,8 +213,13 @@ The existing zod schemas (per-target `schemas.ts`, config schemas in `config.ts`
 through L-D3 so every issue has a range. Zod remains the sole authority (L-D8). Two migrated
 rules carry this category:
 
-- `schema/envelope-shape` — `aipm.config.ts` parses strictly against the envelope schema; legacy
-  code `envelope-invalid`.
+- `schema/envelope-shape` — `aipm.config.ts` loads and parses strictly against the envelope
+  schema. Fires on _any_ failure to resolve the envelope, not only a schema violation: a missing
+  `aipm.config.ts` in a plugin-shaped directory, a file that cannot be imported (syntax error, no
+  usable default export), or a file that imports but violates the schema (#101). The first two
+  carry the config loader's own message; the third expands into one diagnostic per Zod issue. In
+  every case this mirrors `validate()`'s `envelope-invalid` for the same tree — `lint`, `validate`
+  and `build` must agree rather than one staying silent; legacy code `envelope-invalid`.
 - `schema/target-conformance` — every target manifest in a plugin's envelope parses against that
   target's current schema; legacy codes `schema-invalid`, plus the Open Plugins-specific
   `metadata-dir-isolation` and `open-plugins-conformance` (soft, advisory-only) findings the same
diff --git a/packages/core/src/lint/engine.test.ts b/packages/core/src/lint/engine.test.ts
index e7af43c..83fb8b1 100644
--- a/packages/core/src/lint/engine.test.ts
+++ b/packages/core/src/lint/engine.test.ts
@@ -11,6 +11,7 @@ import * as os from 'node:os';
 import * as path from 'node:path';
 import { afterEach, beforeEach, describe, expect, it } from 'vitest';
 import { runBuild } from '../pipeline/build.js';
+import { runValidate } from '../pipeline/validate.js';
 import { synthRegistryRepo } from '../test-support/synth-plugin.js';
 import type { SynthRegistryRepo } from '../test-support/synth-plugin.js';
 import { lint } from './engine.js';
@@ -220,3 +221,105 @@ describe('lint()', () => {
     });
   });
 });
+
+// Regression coverage for #101: #91 made `runValidate` (hard `envelope-invalid`) and `runBuild`
+// (thrown `ConfigLoadError`) catch a plugin-shaped directory missing `aipm.config.ts`, but `lint()`
+// stayed silent for the identical tree. `lint` and `validate` must agree on this case.
+describe('lint() — plugin-shaped repo-root subdirectory missing aipm.config.ts (#91, #101)', () => {
+  it('agrees with runValidate(): both report the equivalent envelope-invalid finding for the same tree', async () => {
+    // Repro shape from #91: a plugins/* dir with a target manifest but no aipm.config.ts.
+    write('plugins/broken/.claude-plugin/plugin.json', { name: 'broken', version: '0.1.0' });
+
+    const [lintResult, validateResult] = await Promise.all([lint(repoRoot), runValidate(repoRoot)]);
+
+    // validate() surfaces its existing hard envelope-invalid finding (unchanged by this fix, #91).
+    const envelopeFindings = validateResult.findings.filter((f) => f.code === 'envelope-invalid');
+    expect(envelopeFindings).toHaveLength(1);
+    expect(envelopeFindings[0]?.plugin).toBe('broken');
+    expect(envelopeFindings[0]?.severity).toBe('hard');
+    expect(validateResult.passed).toBe(false);
+
+    // lint() must now surface the equivalent diagnostic — same rule as a malformed config
+    // (`schema/envelope-shape`), `error` severity (validate's `hard` maps to lint's `error`,
+    // L-D2's findingToDiagnostic), carrying the legacy `envelope-invalid` code, and the identical
+    // message validate reports — not silent, as it was pre-fix.
+    const lintEnvelopeDiagnostics = lintResult.diagnostics.filter(
+      (d) => d.legacyCode === 'envelope-invalid',
+    );
+    expect(lintEnvelopeDiagnostics).toHaveLength(1);
+    expect(lintEnvelopeDiagnostics[0]).toMatchObject({
+      ruleId: 'schema/envelope-shape',
+      category: 'schema',
+      severity: 'error',
+      file: 'broken',
+    });
+    expect(lintEnvelopeDiagnostics[0]?.message).toBe(envelopeFindings[0]?.message);
+  });
+
+  it('emits nothing further beyond the envelope-invalid diagnostic for the config-less plugin', async () => {
+    // No other rule can run without a resolved envelope (engine.ts's `continue` after the failed
+    // loadPluginConfig call) — mirroring validate()'s short-circuit on an unusable envelope.
+    write('plugins/broken/.claude-plugin/plugin.json', { name: 'broken', version: '0.1.0' });
+
+    const result = await lint(repoRoot);
+
+    expect(result.diagnostics.filter((d) => d.file === 'broken')).toHaveLength(1);
+  });
+});
+
+// #101, follow-on: the same lint/validate disagreement exists for an `aipm.config.ts` that is
+// present but cannot be imported (syntax error, no usable default export). `runValidate` reports
+// a hard `envelope-invalid` for it; `lint()` previously returned no diagnostic at all, so a
+// syntax-broken envelope still got a clean bill of health from `lint`.
+describe('lint() — plugin whose aipm.config.ts exists but fails to import (#101)', () => {
+  it('agrees with runValidate(): both report the equivalent envelope-invalid for an unparseable config', async () => {
+    write('plugins/broken/.claude-plugin/plugin.json', { name: 'broken', version: '0.1.0' });
+    // Deliberately unparseable TypeScript — the transpile/import step throws, so the failure
+    // never reaches the envelope schema and is not a ZodError.
+    write('plugins/broken/aipm.config.ts', 'export default {{{ not valid typescript\n');
+
+    const [lintResult, validateResult] = await Promise.all([lint(repoRoot), runValidate(repoRoot)]);
+
+    const envelopeFindings = validateResult.findings.filter((f) => f.code === 'envelope-invalid');
+    expect(envelopeFindings).toHaveLength(1);
+    expect(envelopeFindings[0]?.plugin).toBe('broken');
+    expect(envelopeFindings[0]?.severity).toBe('hard');
+    expect(validateResult.passed).toBe(false);
+
+    const lintEnvelopeDiagnostics = lintResult.diagnostics.filter(
+      (d) => d.legacyCode === 'envelope-invalid',
+    );
+    expect(lintEnvelopeDiagnostics).toHaveLength(1);
+    expect(lintEnvelopeDiagnostics[0]).toMatchObject({
+      ruleId: 'schema/envelope-shape',
+      category: 'schema',
+      severity: 'error',
+      file: 'broken',
+    });
+    // Byte-identical to validate's: both take the ConfigLoadError's own message.
+    expect(lintEnvelopeDiagnostics[0]?.message).toBe(envelopeFindings[0]?.message);
+  });
+
+  it('still reports the schema-violation case as per-issue envelope-invalid diagnostics', async () => {
+    // A config that imports cleanly but violates the envelope schema stays on the ZodError path,
+    // which expands into one diagnostic per issue rather than a single loader-message diagnostic.
+    write('plugins/broken/.claude-plugin/plugin.json', { name: 'broken', version: '0.1.0' });
+    write(
+      'plugins/broken/aipm.config.ts',
+      "import { defineConfig } from '@ai-plugin-marketplace/core';\n" +
+        "export default defineConfig({ version: 'not-semver', targets: ['not-a-target'] });\n",
+    );
+
+    const result = await lint(repoRoot);
+
+    const envelopeDiagnostics = result.diagnostics.filter(
+      (d) => d.legacyCode === 'envelope-invalid',
+    );
+    expect(envelopeDiagnostics.length).toBeGreaterThan(0);
+    for (const d of envelopeDiagnostics) {
+      expect(d.ruleId).toBe('schema/envelope-shape');
+      expect(d.severity).toBe('error');
+      expect(d.message).toMatch(/^Invalid aipm\.config: \[/);
+    }
+  });
+});
diff --git a/packages/core/src/lint/engine.ts b/packages/core/src/lint/engine.ts
index 56c2a3d..203ce95 100644
--- a/packages/core/src/lint/engine.ts
+++ b/packages/core/src/lint/engine.ts
@@ -74,8 +74,9 @@ export async function lint(targetPath: string, options?: LintOptions): Promise<L
     try {
       envelope = (await loadPluginConfig(pluginDir, configCache)).targets;
     } catch {
-      // Unusable envelope: envelopeShapeRule (or the config loader itself) already explains why;
-      // no other rule can run without a resolved envelope.
+      // Unusable envelope: envelopeShapeRule ran first against this same pluginDir and has
+      // already reported why (missing/unimportable/schema-violating aipm.config.ts), so this
+      // failure is never silent; no other rule can run without a resolved envelope.
       continue;
     }
 
diff --git a/packages/core/src/lint/rules/legacy-envelope-shape.ts b/packages/core/src/lint/rules/legacy-envelope-shape.ts
index f23ef0f..ad02e08 100644
--- a/packages/core/src/lint/rules/legacy-envelope-shape.ts
+++ b/packages/core/src/lint/rules/legacy-envelope-shape.ts
@@ -1,33 +1,31 @@
 /**
- * `schema/envelope-shape` — `aipm.config.ts` parses strictly against the envelope schema
+ * `schema/envelope-shape` — `aipm.config.ts` loads and parses strictly against the envelope schema
  * (§10.1 step 1). Wraps the existing `validateEnvelopeShape()` check.
  *
  * Unlike the other migrated rules, this one runs *before* a plugin's envelope (`ctx.envelope`)
  * is known — it is what determines whether the envelope can be trusted at all. It therefore
- * loads the raw `aipm.config.ts` default export itself rather than reading anything off
- * `RuleContext.envelope`, and reports nothing when the config is missing entirely (a missing
- * envelope is `load-config.ts`'s concern, not a shape-validation one).
+ * loads `aipm.config.ts` itself rather than reading anything off `RuleContext.envelope`.
  *
- * Reuses `ctx.configCache` (via {@link loadPluginConfig}) rather than importing the raw config a
- * second time: `loadPluginConfig` transpiles-and-validates once and caches the result, so when
- * the engine's subsequent envelope resolution calls `loadPluginConfig` for the same plugin, it is
- * a cache hit rather than a second jiti transpile. On a `ConfigLoadError` whose `cause` is the
- * `ZodError` `defineConfig` throws for a schema violation, this rule reformats those issues into
- * the same per-issue diagnostics `validateEnvelopeShape` would have produced from the raw value;
- * any other failure (import/syntax error) is left to load-config's own `ConfigLoadError` path in
- * `validate()`'s orchestration.
+ * Every way loading can fail is reported here, so `lint` never stays silent on a tree `validate`
+ * and `build` both flag (#101): a missing `aipm.config.ts` (including a plugin-shaped directory
+ * discovered without one, per #91), a file that cannot be imported (syntax error, no usable
+ * default export), and a file that imports but violates the envelope schema. The first two become
+ * a single `envelope-invalid` diagnostic carrying the loader's own message; the third is expanded
+ * into the same per-issue diagnostics `validateEnvelopeShape` would have produced from the raw
+ * value. This catch mirrors `runValidate()`'s envelope-load catch in `pipeline/validate.ts`, so
+ * the two surfaces agree by construction rather than by a duplicated message string.
+ *
+ * Loading goes through {@link loadPluginConfig} with `ctx.configCache` rather than importing the
+ * raw config a second time: `loadPluginConfig` transpiles-and-validates once and caches the
+ * result, so when the engine's subsequent envelope resolution calls `loadPluginConfig` for the
+ * same plugin, it is a cache hit rather than a second jiti transpile.
  *
  * @see docs/specs/lint-engine.md L-D2
  */
 
-import * as fs from 'node:fs';
 import * as path from 'node:path';
 import { z } from 'zod';
-import {
-  AIPM_CONFIG_FILENAME,
-  ConfigLoadError,
-  loadPluginConfig,
-} from '../../pipeline/load-config.js';
+import { ConfigLoadError, loadPluginConfig } from '../../pipeline/load-config.js';
 import { zodEnvelopeIssuesToFindings } from '../../pipeline/validate.js';
 import { findingToDiagnostic } from '../diagnostic.js';
 import type { Diagnostic, InternalRuleContext, Rule } from '../types.js';
@@ -45,8 +43,6 @@ export const envelopeShapeRule: Rule = {
     appliesTo: ['aipm-repo'],
   },
   async check(ctx: InternalRuleContext): Promise<Diagnostic[]> {
-    const configPath = path.join(ctx.pluginDir, AIPM_CONFIG_FILENAME);
-    if (!fs.existsSync(configPath)) return [];
     const pluginName = path.basename(ctx.pluginDir);
     try {
       // A cache hit here (already validated by an earlier call in this invocation) means the
@@ -58,9 +54,18 @@ export const envelopeShapeRule: Rule = {
         const findings = zodEnvelopeIssuesToFindings(err.cause.issues, pluginName);
         return findings.map((f) => findingToDiagnostic(f, RULE_ID, 'schema', docsUrlFor(RULE_ID)));
       }
-      // Import failure (syntax error, etc.) is reported by load-config's own ConfigLoadError
-      // path in validate()'s orchestration; nothing further to add here.
-      return [];
+      // Missing file, import/syntax failure, or an unexpected throw. Reported exactly as
+      // runValidate()'s envelope-load catch reports it — same code, same severity, and the
+      // loader's own message verbatim, so lint and validate cannot drift apart.
+      const message = err instanceof Error ? err.message : String(err);
+      return [
+        findingToDiagnostic(
+          { severity: 'hard', code: 'envelope-invalid', plugin: pluginName, message },
+          RULE_ID,
+          'schema',
+          docsUrlFor(RULE_ID),
+        ),
+      ];
     }
   },
 };