diff --git a/docs/work/_state.json b/docs/work/_state.json
index e74ddfa..bfe0403 100644
--- a/docs/work/_state.json
+++ b/docs/work/_state.json
@@ -1,5 +1,5 @@
 {
-  "updated_at": "2026-05-13T06:32:59.719Z",
+  "updated_at": "2026-05-13T06:47:32.677Z",
   "epics": {
     "agent-workflow-docs-v1": {
       "status": "done",
@@ -202,6 +202,56 @@
         }
       }
     },
+    "fallow-integration-v1": {
+      "status": "in-progress",
+      "title": "Fallow integration v1 — whole-codebase static analysis as 5th gate",
+      "stories": {
+        "01-fallow-install": {
+          "status": "in-progress",
+          "title": "Install fallow + create .fallowrc.json",
+          "ac_total": 4,
+          "ac_completed": 0,
+          "depends_on": [],
+          "blocks": [
+            "02-pnpm-turbo-wiring"
+          ]
+        },
+        "02-pnpm-turbo-wiring": {
+          "status": "todo",
+          "title": "pnpm script + turbo task wiring",
+          "ac_total": 4,
+          "ac_completed": 0,
+          "depends_on": [
+            "01-fallow-install"
+          ],
+          "blocks": [
+            "03-ci-integration"
+          ]
+        },
+        "03-ci-integration": {
+          "status": "todo",
+          "title": "CI workflow runs pnpm fallow",
+          "ac_total": 2,
+          "ac_completed": 0,
+          "depends_on": [
+            "02-pnpm-turbo-wiring"
+          ],
+          "blocks": [
+            "04-docs-and-prompts"
+          ]
+        },
+        "04-docs-and-prompts": {
+          "status": "todo",
+          "title": "Docs + agent prompt updates",
+          "ac_total": 5,
+          "ac_completed": 0,
+          "depends_on": [
+            "03-ci-integration"
+          ],
+          "blocks": []
+        }
+      }
+    },
     "frontend-conformance-v1": {
       "status": "done",
       "title": "Frontend conformance rules v1",
@@ -359,6 +409,37 @@
       }
     }
   },
-  "ready": [],
-  "blocked": []
+  "ready": [
+    {
+      "epic": "fallow-integration-v1",
+      "story": "01-fallow-install",
+      "title": "Install fallow + create .fallowrc.json"
+    }
+  ],
+  "blocked": [
+    {
+      "epic": "fallow-integration-v1",
+      "story": "02-pnpm-turbo-wiring",
+      "title": "pnpm script + turbo task wiring",
+      "waiting_on": [
+        "fallow-integration-v1/01-fallow-install"
+      ]
+    },
+    {
+      "epic": "fallow-integration-v1",
+      "story": "03-ci-integration",
+      "title": "CI workflow runs pnpm fallow",
+      "waiting_on": [
+        "fallow-integration-v1/02-pnpm-turbo-wiring"
+      ]
+    },
+    {
+      "epic": "fallow-integration-v1",
+      "story": "04-docs-and-prompts",
+      "title": "Docs + agent prompt updates",
+      "waiting_on": [
+        "fallow-integration-v1/03-ci-integration"
+      ]
+    }
+  ]
 }
diff --git a/docs/work/fallow-integration-v1/01-fallow-install/_story.md b/docs/work/fallow-integration-v1/01-fallow-install/_story.md
new file mode 100644
index 0000000..a69c9e9
--- /dev/null
+++ b/docs/work/fallow-integration-v1/01-fallow-install/_story.md
@@ -0,0 +1,17 @@
+---
+id: 01-fallow-install
+epic: fallow-integration-v1
+title: Install fallow + create .fallowrc.json
+type: technical-story
+status: in-progress
+feature: tooling
+depends-on: []
+blocks: [02-pnpm-turbo-wiring]
+---
+
+## Tasks
+
+- [ ] Story scaffold
+- [ ] Add fallow to root devDependencies
+- [ ] Create .fallowrc.json with monorepo-aware config
+- [ ] Verify `pnpm exec fallow --version` works
diff --git a/docs/work/fallow-integration-v1/02-pnpm-turbo-wiring/_story.md b/docs/work/fallow-integration-v1/02-pnpm-turbo-wiring/_story.md
new file mode 100644
index 0000000..3016153
--- /dev/null
+++ b/docs/work/fallow-integration-v1/02-pnpm-turbo-wiring/_story.md
@@ -0,0 +1,17 @@
+---
+id: 02-pnpm-turbo-wiring
+epic: fallow-integration-v1
+title: pnpm script + turbo task wiring
+type: technical-story
+status: todo
+feature: tooling
+depends-on: [01-fallow-install]
+blocks: [03-ci-integration]
+---
+
+## Tasks
+
+- [ ] pnpm fallow script (runs all)
+- [ ] pnpm fallow:audit script (runs `fallow audit --base main`)
+- [ ] turbo.json task entry for fallow
+- [ ] Run `pnpm fallow` against current repo, capture findings, tune config
diff --git a/docs/work/fallow-integration-v1/03-ci-integration/_story.md b/docs/work/fallow-integration-v1/03-ci-integration/_story.md
new file mode 100644
index 0000000..631fcc5
--- /dev/null
+++ b/docs/work/fallow-integration-v1/03-ci-integration/_story.md
@@ -0,0 +1,15 @@
+---
+id: 03-ci-integration
+epic: fallow-integration-v1
+title: CI workflow runs pnpm fallow
+type: technical-story
+status: todo
+feature: ci
+depends-on: [02-pnpm-turbo-wiring]
+blocks: [04-docs-and-prompts]
+---
+
+## Tasks
+
+- [ ] Add `pnpm fallow` step after `pnpm conformance` in ci.yml
+- [ ] Use --format annotations for inline GH PR comments
diff --git a/docs/work/fallow-integration-v1/04-docs-and-prompts/_story.md b/docs/work/fallow-integration-v1/04-docs-and-prompts/_story.md
new file mode 100644
index 0000000..7cd200b
--- /dev/null
+++ b/docs/work/fallow-integration-v1/04-docs-and-prompts/_story.md
@@ -0,0 +1,18 @@
+---
+id: 04-docs-and-prompts
+epic: fallow-integration-v1
+title: Docs + agent prompt updates
+type: technical-story
+status: todo
+feature: agent-prompts
+depends-on: [03-ci-integration]
+blocks: []
+---
+
+## Tasks
+
+- [ ] Update CLAUDE.md conformance-system section to list Fallow as 5th gate
+- [ ] Update docs/guides/conformance-quickref.md with Fallow row
+- [ ] Update .sandcastle/implementer.prompt.md: run `fallow audit` before commit
+- [ ] Update .sandcastle/reviewer.prompt.md: verify implementer ran fallow audit
+- [ ] Final verification + closeout
diff --git a/docs/work/fallow-integration-v1/_epic.md b/docs/work/fallow-integration-v1/_epic.md
new file mode 100644
index 0000000..65c68f7
--- /dev/null
+++ b/docs/work/fallow-integration-v1/_epic.md
@@ -0,0 +1,28 @@
+---
+id: fallow-integration-v1
+prd: null
+title: Fallow integration v1 — whole-codebase static analysis as 5th gate
+type: epic
+status: in-progress
+features: [tooling, ci, agent-prompts]
+created: 2026-05-13
+---
+
+## Goal
+
+Wire Fallow as the 5th conformance gate: install, configure, pnpm script,
+turbo task, CI step, docs update, agent prompt update.
+
+## Why
+
+Fallow catches what file-local lint, type-check, manifest assertions, and
+conformance event closure cannot — dead code, dupes, circular deps,
+complexity hotspots, and AI-change drift. `fallow audit --base main` is
+purpose-built for AI agents to self-validate before submission.
+
+## Stories
+
+- [ ] [01 — Install fallow + .fallowrc.json](01-fallow-install/_story.md)
+- [ ] [02 — pnpm + turbo wiring](02-pnpm-turbo-wiring/_story.md)
+- [ ] [03 — CI workflow integration](03-ci-integration/_story.md)
+- [ ] [04 — Docs + agent prompt updates](04-docs-and-prompts/_story.md)