diff --git a/.github/workflows/fluid-vendor-sync.yml b/.github/workflows/fluid-vendor-sync.yml
new file mode 100644
index 0000000..748d170
--- /dev/null
+++ b/.github/workflows/fluid-vendor-sync.yml
@@ -0,0 +1,78 @@
+# The vendored FLUID schemas under vendor/fluid/ must match what FLUID publishes.
+#
+# FLUX does not own the FLUID schema; it references it across the seam. The copies
+# in vendor/fluid/ exist so the validator can resolve a referenced contract offline,
+# which means they are a cache — and an unguarded cache drifts.
+#
+# They are in sync today. Nothing enforced that, which is the actual gap: a claim
+# about another project's artefact is only true if the CI of the side making the
+# claim proves it. That is the rule this repository now applies to itself after
+# shipping a false "field-to-field aligned with FLUID" statement through several
+# releases (see docs/reconciliation.md).
+#
+# Comparison is on canonical JSON (sorted keys, no whitespace) so cosmetic
+# formatting differences do not fail the build — only a real content divergence does.
+
+name: fluid-vendor-sync
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "vendor/fluid/**"
+      - ".github/workflows/fluid-vendor-sync.yml"
+  pull_request:
+    paths:
+      - "vendor/fluid/**"
+      - ".github/workflows/fluid-vendor-sync.yml"
+  schedule:
+    # Weekly: FLUID can publish a new patch without FLUX touching anything, and a
+    # cache that silently ages is exactly what this guards against.
+    - cron: "0 6 * * 1"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+env:
+  FLUID_RAW_BASE: https://raw.githubusercontent.com/open-data-protocol/fluid/main/schema
+
+jobs:
+  vendor-sync:
+    name: vendored FLUID schemas match upstream
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: compare each vendored schema against the published one
+        run: |
+          set -euo pipefail
+          status=0
+          for path in vendor/fluid/fluid-schema-*.json; do
+            name="$(basename "$path")"
+            if ! curl -fsSL "${FLUID_RAW_BASE}/${name}" -o "/tmp/${name}"; then
+              echo "::error::${name} is vendored here but not published upstream."
+              echo "::error::Either it was withdrawn, or this copy was never a real FLUID release."
+              status=1
+              continue
+            fi
+            if python3 - "$path" "/tmp/${name}" <<'PY'
+          import json, sys
+          canon = lambda p: json.dumps(json.load(open(p)), sort_keys=True, separators=(",", ":"))
+          sys.exit(0 if canon(sys.argv[1]) == canon(sys.argv[2]) else 1)
+          PY
+            then
+              echo "✅ ${name} matches upstream"
+            else
+              echo "::error::${name} has drifted from the published FLUID schema."
+              echo "::error::Re-vendor it: curl -fsSL ${FLUID_RAW_BASE}/${name} -o ${path}"
+              echo "::error::then run: python3 scripts/sync-package-data.py"
+              diff <(python3 -m json.tool --sort-keys "$path") \
+                   <(python3 -m json.tool --sort-keys "/tmp/${name}") | head -40 || true
+              status=1
+            fi
+          done
+          exit $status
diff --git a/docs/reconciliation.md b/docs/reconciliation.md
index 2102c0b..d07c842 100644
--- a/docs/reconciliation.md
+++ b/docs/reconciliation.md
@@ -36,17 +36,74 @@ matching FLUID's conventions.
 
 ### Governed — delivered in schema, cross-checks in the validator
 - `agentPolicy` (root-level, all kinds): model allow-list, token budget,
-  use-case limits — vocabulary aligned with FLUID `exposes[].policy.agentPolicy`.
+  use-case limits. **Not** field-for-field with FLUID — see "The agentPolicy
+  divergence" below.
 - `skills` (root-level, all kinds): the uniform agentic extension point of
   paper §3.5. Declaring `skills` requires `agentPolicy` (schema-enforced).
 - `sovereignty` on `World` and `Simulation` (`allowedZones`, `enforcement: block|audit`).
-- `ConsentProfile` can no longer be empty, and its vocabulary
-  (`allowedUseCases`/`deniedUseCases`) matches FLUID's, so seam-crossing policy
-  comparison is field-to-field. The "contract must be at least as strict as the
-  gating ConsentProfile" rule is enforced by the reference validator at the
-  seam: an emitted expose's `policy.agentPolicy` may not allow a use case a
-  gating profile denies, nor exceed its allow-list (`scripts/validate.py`,
-  regression-tested).
+- `ConsentProfile` can no longer be empty. The "contract must be at least as
+  strict as the gating ConsentProfile" rule is enforced by the reference
+  validator at the seam: an emitted expose's `policy.agentPolicy` may not allow
+  a use case a gating profile denies, nor exceed its allow-list
+  (`scripts/validate.py`, regression-tested). **That enforcement is real, but
+  its reach is narrower than this document previously claimed** — see below.
+
+
+## The agentPolicy divergence
+
+This document previously said FLUX's `agentPolicy` vocabulary was "aligned with
+FLUID's" and that "seam-crossing policy comparison is field-to-field". Both
+statements were wrong, and the schema carried the same claim in its own
+`$defs/agentPolicy` description. They are corrected here rather than quietly
+dropped, because a false alignment claim is worse than a documented gap: it
+invites implementers to build a comparison that cannot work.
+
+Measured against `fluid-schema-0.7.5.json`:
+
+| | FLUX `agentPolicy` | FLUID `exposes[].policy.agentPolicy` |
+|---|---|---|
+| members | 5 | 13 |
+| token budget | `tokenBudget` (integer) | `maxTokensPerRequest` + `maxTokensPerDay` |
+| `purposeLimitation` | boolean | string |
+| use-case values | free strings (`minLength: 1`) | 12-value enum |
+| FLUID-only | — | `deniedModels`, `canReason`, `canStore`, `retentionPolicy`, `auditRequired`, `tags`, `labels` |
+
+Three members line up by name *and* type: `allowedModels`, `allowedUseCases`,
+`deniedUseCases`.
+
+### What this costs at the seam
+
+The use-case row is the one that bites. FLUX accepts any non-empty string;
+FLUID accepts twelve specific values. So a `ConsentProfile` can deny a use case
+that no FLUID contract is able to express, and the "at least as strict" check
+then has nothing to bind against on the FLUID side.
+
+This is not hypothetical. Of the eleven distinct use-case values appearing in
+FLUX's own 34 enforcement vectors — `advertising`, `persona_variation`,
+`journey_synthesis`, `pricing_optimisation`, `exfiltrate-pii` and the rest —
+**none** can be written into a FLUID contract. The seam comparison the previous
+wording described has never had a working example in this repository's test
+suite.
+
+What the validator does enforce is still worth having: within FLUX, a
+simulation's declared policy is checked against its gating profile, and that is
+regression-tested. What it cannot do is carry a FLUX use-case restriction
+across the seam into a FLUID contract.
+
+### Resolving it
+
+Two options, and this is an open decision, not a plan:
+
+1. **FLUX rebases onto FLUID's vocabulary** — `$ref` FLUID's published
+   `agentPolicy` `$id` instead of restating it. Cleanest, and it makes the seam
+   claim true. It is a breaking change to FLUX (`tokenBudget` splits in two,
+   `purposeLimitation` changes type, use-case values become constrained) and the
+   34 vectors would need rebasing. Cheapest while FLUX has no external
+   implementers.
+2. **FLUX keeps its own vocabulary** and this table stands as the permanent,
+   honest statement of what does and does not cross the seam.
+
+Either way the rule holds: no alignment claim without a CI gate that can fail.
 
 ## The four seams (paper §3.4)
 
diff --git a/flux_spec/data/schema/flux-schema-0.5.0.json b/flux_spec/data/schema/flux-schema-0.5.0.json
index ba90a3a..e63b6a0 100644
--- a/flux_spec/data/schema/flux-schema-0.5.0.json
+++ b/flux_spec/data/schema/flux-schema-0.5.0.json
@@ -1562,7 +1562,7 @@
           "default": true
         }
       },
-      "description": "Vocabulary aligned with FLUID's exposes[].policy.agentPolicy so seam-crossing policy comparison is field-to-field."
+      "description": "FLUX's own agent-policy vocabulary. It is NOT field-for-field identical to FLUID's exposes[].policy.agentPolicy and must not be compared as if it were: FLUX declares 5 members to FLUID's 13, FLUX's tokenBudget has no FLUID counterpart (FLUID splits it into maxTokensPerRequest and maxTokensPerDay), purposeLimitation is boolean here and a string in FLUID, and FLUX's use-case values are free strings where FLUID constrains them to a 12-value enum. See docs/reconciliation.md for the divergence table and what the seam validator can and cannot enforce because of it."
     },
     "skillBinding": {
       "type": "object",
diff --git a/flux_spec/data/schema/flux-schema-latest.json b/flux_spec/data/schema/flux-schema-latest.json
index ba90a3a..e63b6a0 100644
--- a/flux_spec/data/schema/flux-schema-latest.json
+++ b/flux_spec/data/schema/flux-schema-latest.json
@@ -1562,7 +1562,7 @@
           "default": true
         }
       },
-      "description": "Vocabulary aligned with FLUID's exposes[].policy.agentPolicy so seam-crossing policy comparison is field-to-field."
+      "description": "FLUX's own agent-policy vocabulary. It is NOT field-for-field identical to FLUID's exposes[].policy.agentPolicy and must not be compared as if it were: FLUX declares 5 members to FLUID's 13, FLUX's tokenBudget has no FLUID counterpart (FLUID splits it into maxTokensPerRequest and maxTokensPerDay), purposeLimitation is boolean here and a string in FLUID, and FLUX's use-case values are free strings where FLUID constrains them to a 12-value enum. See docs/reconciliation.md for the divergence table and what the seam validator can and cannot enforce because of it."
     },
     "skillBinding": {
       "type": "object",
diff --git a/schema/flux-schema-0.5.0.json b/schema/flux-schema-0.5.0.json
index ba90a3a..e63b6a0 100644
--- a/schema/flux-schema-0.5.0.json
+++ b/schema/flux-schema-0.5.0.json
@@ -1562,7 +1562,7 @@
           "default": true
         }
       },
-      "description": "Vocabulary aligned with FLUID's exposes[].policy.agentPolicy so seam-crossing policy comparison is field-to-field."
+      "description": "FLUX's own agent-policy vocabulary. It is NOT field-for-field identical to FLUID's exposes[].policy.agentPolicy and must not be compared as if it were: FLUX declares 5 members to FLUID's 13, FLUX's tokenBudget has no FLUID counterpart (FLUID splits it into maxTokensPerRequest and maxTokensPerDay), purposeLimitation is boolean here and a string in FLUID, and FLUX's use-case values are free strings where FLUID constrains them to a 12-value enum. See docs/reconciliation.md for the divergence table and what the seam validator can and cannot enforce because of it."
     },
     "skillBinding": {
       "type": "object",
diff --git a/schema/flux-schema-latest.json b/schema/flux-schema-latest.json
index ba90a3a..e63b6a0 100644
--- a/schema/flux-schema-latest.json
+++ b/schema/flux-schema-latest.json
@@ -1562,7 +1562,7 @@
           "default": true
         }
       },
-      "description": "Vocabulary aligned with FLUID's exposes[].policy.agentPolicy so seam-crossing policy comparison is field-to-field."
+      "description": "FLUX's own agent-policy vocabulary. It is NOT field-for-field identical to FLUID's exposes[].policy.agentPolicy and must not be compared as if it were: FLUX declares 5 members to FLUID's 13, FLUX's tokenBudget has no FLUID counterpart (FLUID splits it into maxTokensPerRequest and maxTokensPerDay), purposeLimitation is boolean here and a string in FLUID, and FLUX's use-case values are free strings where FLUID constrains them to a 12-value enum. See docs/reconciliation.md for the divergence table and what the seam validator can and cannot enforce because of it."
     },
     "skillBinding": {
       "type": "object",