Davincc77 · Davincc77 · May 24, 2026 · May 24, 2026
diff --git a/SCHEMA_INDEX.md b/SCHEMA_INDEX.md
@@ -4,8 +4,8 @@
 
 | Directory | Form | When to use |
 |-----------|------|-------------|
-| [`schema/`](./schema/) | **Unified** — one file per spec version validates the whole document. Files: `klickd-v1.json`, `klickd-v2.json`, `klickd-v3.4.schema.json`. | Single-pass validators, schema registries, third-party tooling. |
-| [`schemas/`](./schemas/) | **Split** — separate envelope and payload schemas for v3. Files: `klickd-envelope-v3.schema.json`, `klickd-payload-v3.schema.json`. | Secure decoders that validate the envelope *before* decryption and the payload *after*. |
+| [`schema/`](./schema/) | **Unified** — one file per spec version validates the whole document. Files: `klickd-v1.json`, `klickd-v2.json`, `klickd-v3.4.schema.json`, `klickd-v4-preview.schema.json` (preview), `klickd-v4.schema.json` (GA strict candidate). | Single-pass validators, schema registries, third-party tooling. |
+| [`schemas/`](./schemas/) | **Split** — separate envelope and payload schemas. Files: `klickd-envelope-v3.schema.json`, `klickd-payload-v3.schema.json`, `klickd-payload-v4-preview.schema.json` (preview), `klickd-payload-v4.schema.json` (GA strict candidate). | Secure decoders that validate the envelope *before* decryption and the payload *after*. |
 
 Both directories are **normative for v3.x (production, current and recommended)** and are kept in sync. The split form (`schemas/`) is the canonical pre-/post-decrypt boundary; the unified form (`schema/`) is the convenience form for single-shot validation.
 
@@ -30,7 +30,27 @@ In addition to the normative v3 schemas, the repository ships **permissive previ
 **These schemas are PERMISSIVE.** They use `additionalProperties: true` and only declare top-level hooks for the preview fields. They are intended to **accept and preserve** draft v4 structures, not to perform strict validation. They MUST NOT be used to reject a file that is otherwise a valid v3.5.1 file.
 
 - **Normative for production?** No. Production validation MUST use `schema/klickd-v3.4.schema.json` or the split v3 schemas under `schemas/`.
-- **Strict v4 validation?** Not in this preview. A future PR will introduce strict v4 schemas; until then, the preview schemas are deliberately loose.
+- **Strict v4 validation?** See the **v4 GA strict schemas** section below.
 - **Unknown fields?** A v4-preview reader MUST preserve unknown fields verbatim when round-tripping. See SPEC.md §33.7.
 
 See [SPEC.md §33](./SPEC.md) and the RFCs under [`docs/rfcs/`](./docs/rfcs/) for the design source.
+
+---
+
+## v4 GA strict schemas (P0-2 — coexist with preview, do NOT supersede it)
+
+To unblock the GA track described in [`docs/roadmap/ROAD-TO-V4-GA.md` §P0-2](./docs/roadmap/ROAD-TO-V4-GA.md), the repository now also ships **strict v4 schemas**. The preview schemas remain in place unchanged: both pairs coexist until the preview sunset is announced separately.
+
+| File | Form | Status | When to use |
+|------|------|--------|-------------|
+| [`schemas/klickd-payload-v4.schema.json`](./schemas/klickd-payload-v4.schema.json) | **Split — payload** | **GA strict candidate (normative target)** | Strict validation of a `.klickd` v4 decrypted payload: `verification_gates` (v1 core enum), `human_veto_policy`, `claim_sources` (v1), `media_profile` (RFC-001 v1, `version`+`entries[]`, hash strict), `migration` (RFC-004 v1 frozen fields), plus carry-over v3 surface. RFC-002 v2-additive fields (`reversibility`, `blast_radius`, `contract_tests`, `success_criteria`, `verification_artifacts`) remain permissive while Draft. |
+| [`schema/klickd-v4.schema.json`](./schema/klickd-v4.schema.json) | **Unified** | **GA strict candidate (normative target)** | Strict validation of a full v4 document. Encrypted files MUST carry `kdf` + `cipher` + `ciphertext` (envelope-v3 contract unchanged per §33.10 #2). |
+
+**Coexistence rules:**
+
+- Preview schemas (`*-v4-preview.schema.json`) remain authoritative for **preview** files (`preview: "v4.0.0-preview.1"`). They MUST continue to accept all preview vectors.
+- Strict schemas (`klickd-payload-v4.schema.json`, `klickd-v4.schema.json`) are the **GA strict target**. They accept both `payload_schema_version: "4.0"` (GA) and the legacy preview value `"4.0.0-preview.1"` so the 5 persona examples and preview vectors round-trip against them.
+- **Top-level `additionalProperties: true` is preserved.** SPEC.md §33.7 (unknown-field preservation) is unconditional and not relaxed by the strict schemas.
+- **No SDK is bumped.** No npm / PyPI / Zenodo release is triggered. No git tag is created.
+
+**Validation:** see [`scripts/validate_v4_schemas.py`](./scripts/validate_v4_schemas.py) for the canonical local validation runner.
diff --git a/docs/roadmap/ROAD-TO-V4-GA.md b/docs/roadmap/ROAD-TO-V4-GA.md
@@ -106,6 +106,19 @@ Chaque entrée précise : *Objet → Livrables → Critères de sortie (Definiti
   - validation passe sur tous les vectors v4 stricts ;
   - les vectors preview restent acceptés via le schéma preview (deux schémas coexistent jusqu’au sunset).
 - **Dépendances :** P0-1.
+- **Statut (2026-05-24) :** **GA candidate landed (docs/schema only, no SDK/release).** Le PR P0-2 introduit
+  [`schemas/klickd-payload-v4.schema.json`](../../schemas/klickd-payload-v4.schema.json) et
+  [`schema/klickd-v4.schema.json`](../../schema/klickd-v4.schema.json) (strict sur les sections RFC-001 v1
+  `Accepted` et RFC-002 v1 core `Accepted` ; permissif sur les sections RFC-002 v2-additive et RFC-004 encore
+  en `Draft`). `additionalProperties: true` est conservé **au niveau racine** pour respecter le contrat de
+  préservation des champs inconnus de [SPEC.md §33.7](../../SPEC.md). Les 5 personas de
+  [`examples/v4/personas/`](../../examples/v4/personas/) et tous les `expected_payload` de
+  [`tests/vectors_v40_preview.json`](../../tests/vectors_v40_preview.json) valident contre le schéma strict.
+  Les schémas preview restent en place inchangés (coexistence, pas de remplacement). **Aucun bump de version
+  SDK, aucun tag, aucune release npm/PyPI/Zenodo.** Le runner local est
+  [`scripts/validate_v4_schemas.py`](../../scripts/validate_v4_schemas.py). Les vectors v4 *stricts*
+  (P0-6) restent à produire avant de pouvoir cocher la DoD complète ; à ce stade la DoD est validée sur le
+  corpus preview existant et les 5 personas.
 
 #### P0-3 — SDK Python `klickd` 4.0.0
 

diff --git a/examples/v4/personas/README.md b/examples/v4/personas/README.md
@@ -123,10 +123,12 @@ forte sur les sections preview).
 - [x] Passphrase de test publique documentée (`klickd-example-only`), sans
       jamais figurer comme contenu chiffré.
 - [x] Validation contre le schéma preview permissif (cf. §5 ci-dessous).
-- [ ] Validation stricte v4 ([P0-2 / P0-6](../../../docs/roadmap/ROAD-TO-V4-GA.md)) :
-      **différée**. Le schéma strict v4 et les vectors stricts v4 n'existent
-      pas encore — la DoD complète sera atteignable une fois P0-2/P0-6 mergés,
-      conformément à l'ordre des dépendances inscrit dans ROAD-TO-V4-GA.
+- [x] Validation stricte v4 contre [`schemas/klickd-payload-v4.schema.json`](../../../schemas/klickd-payload-v4.schema.json)
+      (P0-2 GA candidate, livré séparément). Les 5 personas valident sans erreur —
+      voir [`scripts/validate_v4_schemas.py`](../../../scripts/validate_v4_schemas.py).
+- [ ] Validation contre les vectors v4 *stricts*
+      ([P0-6](../../../docs/roadmap/ROAD-TO-V4-GA.md)) :
+      **différée**. Les vectors v4 stricts n'existent pas encore — track P0-6.
 
 ### Reproduire la validation locale
 

diff --git a/schema/README.md b/schema/README.md
@@ -8,6 +8,7 @@ This directory contains **unified** JSON Schemas — each file validates a compl
 | `klickd-v2.json` | v2.x | PBKDF2-SHA256 + 4-field AAD. |
 | `klickd-v3.4.schema.json` | v3.4 (current) | Argon2id + RFC 8785 JCS AAD + `kdf`/`cipher` blocks. Forward-compatible with v3.5 fields. |
 | `klickd-v4-preview.schema.json` | **v4.0.0-preview.1 (PREVIEW, non-normative, NOT GA)** | Permissive (`additionalProperties: true`) acceptance schema for draft v4 documents with top-level hooks for `media_profile` / `verification_gates` / `human_veto_policy` / `claim_sources` / `verification_artifacts` / `migration` / `context_cost` / `profile_kind`. See SPEC.md §33. |
+| `klickd-v4.schema.json` | **v4 GA strict candidate (P0-2)** | Strict unified schema. Encrypted v4 files MUST carry `kdf` + `cipher` + `ciphertext` (envelope-v3 contract unchanged per §33.10 #2). Inline payload fields cross-reference `../schemas/klickd-payload-v4.schema.json`. Top-level `additionalProperties: true` preserved (SPEC.md §33.7). Coexists with the preview schema — does NOT supersede it. |
 
 **Use these files** when a single-schema validation is sufficient (CI tooling, third-party integrations, schema registries).
 

diff --git a/schema/klickd-v4.schema.json b/schema/klickd-v4.schema.json
@@ -0,0 +1,129 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://klickd.app/schema/v4/klickd.schema.json",
+  "title": "klickd v4 — Unified (Strict GA candidate, normative)",
+  "description": "Strict unified JSON Schema for a .klickd v4 document (envelope + optional inline payload). This schema is the GA strict equivalent of the permissive klickd-v4-preview.schema.json. It validates the envelope shape strictly (mirroring the v3 envelope contract — Argon2id + AES-256-GCM is unchanged in v4 per SPEC.md §33.10 #2) and, for unencrypted files, validates the inline payload against the strict v4 payload schema (klickd-payload-v4.schema.json). Top-level additionalProperties is TRUE to preserve unknown fields verbatim (SPEC.md §33.7 forward-compatibility invariant). Does NOT supersede the permissive preview schema (klickd-v4-preview.schema.json) — both coexist.",
+  "type": "object",
+  "additionalProperties": true,
+  "required": ["klickd_version", "created_at", "encrypted"],
+  "properties": {
+    "klickd_version": {
+      "type": "string",
+      "description": "Wire / envelope version. Strict v4 GA producers SHOULD emit '4.0'. v3.x values are also accepted because the v3 envelope contract is unchanged (§33.10 #2) and a v3.x file remains readable by a v4 reader.",
+      "pattern": "^(3|4)\\.\\d+(\\.[0-9A-Za-z-.]+)?$"
+    },
+    "preview": {
+      "type": "string",
+      "description": "OPTIONAL preview marker. Absent on GA strict files. If present, this file was written against a preview iteration (e.g. 'v4.0.0-preview.1')."
+    },
+    "created_at": {
+      "type": "string",
+      "description": "RFC 3339 UTC timestamp of file creation. Z-suffix only, no fractional seconds (matches v3 envelope strict contract).",
+      "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z$"
+    },
+    "encrypted": {
+      "type": "boolean"
+    },
+    "domain": {
+      "type": "string",
+      "minLength": 1,
+      "description": "Semantic category. Registered values follow v3 (education, work, finance, legal, creative, health, research, robotics, gaming, creator). Custom non-empty strings are permitted."
+    },
+    "profile_kind": {
+      "type": "string",
+      "description": "Top-level discriminator for the profile shape. Reserved canonical values: 'learner', 'agent', 'team', 'robot', 'creator'."
+    },
+    "domain_schema_version": {
+      "type": "string",
+      "pattern": "^([a-z][a-z0-9_-]*-\\d+\\.\\d+|\\d+\\.\\d+(\\.\\d+)?)$"
+    },
+    "kdf": {
+      "type": "object",
+      "description": "Structured KDF block — same contract as envelope-v3 §15.",
+      "required": ["name", "params", "salt"],
+      "additionalProperties": false,
+      "properties": {
+        "name": {"type": "string", "enum": ["argon2id", "pbkdf2-sha256"]},
+        "params": {
+          "oneOf": [
+            {
+              "type": "object",
+              "required": ["m", "t", "p"],
+              "additionalProperties": false,
+              "properties": {
+                "m": {"type": "integer", "minimum": 65536},
+                "t": {"type": "integer", "minimum": 1},
+                "p": {"type": "integer", "minimum": 1}
+              }
+            },
+            {
+              "type": "object",
+              "required": ["iterations"],
+              "additionalProperties": false,
+              "properties": {
+                "iterations": {"type": "integer", "minimum": 600000}
+              }
+            }
+          ]
+        },
+        "salt": {"type": "string"}
+      }
+    },
+    "cipher": {
+      "type": "object",
+      "description": "Structured cipher block — same contract as envelope-v3 §16. v4 does not introduce a new cipher.",
+      "required": ["name", "iv"],
+      "additionalProperties": false,
+      "properties": {
+        "name": {"type": "string", "const": "AES-256-GCM"},
+        "iv": {"type": "string"}
+      }
+    },
+    "ciphertext": {
+      "type": "string",
+      "description": "AES-256-GCM ciphertext (base64 padded). Required when encrypted=true."
+    },
+    "iv": {
+      "type": "string",
+      "description": "Legacy top-level IV mirror, retained for v3.0 round-trip parity. New producers SHOULD place IV inside the structured cipher block."
+    },
+    "kdf_salt": {
+      "type": "string",
+      "description": "Legacy top-level salt mirror, retained for v3.0 round-trip parity."
+    },
+    "payload_schema_version": {
+      "type": "string",
+      "description": "Payload schema version when the payload is inline (encrypted=false). Strict v4 GA value: '4.0'. Preview '4.0.0-preview.1' accepted for round-trip.",
+      "enum": ["4.0", "4.0.0-preview.1"]
+    },
+    "media_profile": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/media_profile"},
+    "verification_gates": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/verification_gates"},
+    "human_veto_policy": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/human_veto_policy"},
+    "claim_sources": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/claim_sources"},
+    "verification_artifacts": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/verification_artifacts"},
+    "contract_tests": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/contract_tests"},
+    "success_criteria": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/success_criteria"},
+    "reversibility": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/reversibility"},
+    "blast_radius": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/blast_radius"},
+    "risk_thresholds": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/risk_thresholds"},
+    "preflight_checks": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/preflight_checks"},
+    "error_journal": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/error_journal"},
+    "migration": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/migration"},
+    "context_cost": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/context_cost"},
+    "gaming_profile": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/gaming_profile"},
+    "deprecated_fields": {"$ref": "https://klickd.app/schemas/v4/klickd-payload.schema.json#/properties/deprecated_fields"}
+  },
+  "allOf": [
+    {
+      "if": {
+        "type": "object",
+        "properties": {"encrypted": {"const": true}},
+        "required": ["encrypted"]
+      },
+      "then": {
+        "required": ["kdf", "cipher", "ciphertext"],
+        "description": "Encrypted v4 file MUST carry kdf + cipher + ciphertext (envelope-v3 contract retained)."
+      }
+    }
+  ]
+}
diff --git a/schemas/README.md b/schemas/README.md
@@ -7,6 +7,7 @@ This directory contains the **split** JSON Schemas for `.klickd` v3:
 | `klickd-envelope-v3.schema.json` | Outer JSON envelope (encrypted). Validates `klickd_version`, `kdf`, `cipher`, `ciphertext`, AAD-relevant fields. |
 | `klickd-payload-v3.schema.json` | Inner decrypted payload. Validates `identity`, `agent_instructions`, `user_preferences`, `context`, `knowledge`, `memory`, etc. |
 | `klickd-payload-v4-preview.schema.json` | **v4.0.0-preview.1 payload (PREVIEW, non-normative, NOT GA).** Permissive (`additionalProperties: true`) acceptance schema for draft v4 payloads with top-level hooks for `media_profile` / `verification_gates` / `human_veto_policy` / `claim_sources` / `verification_artifacts` / `migration` / `context_cost` / `profile_kind`. See SPEC.md §33. |
+| `klickd-payload-v4.schema.json` | **v4 GA strict candidate (P0-2).** Strict payload schema: `verification_gates` (v1 enum), `human_veto_policy`, `claim_sources` (v1), `media_profile` (RFC-001 v1, `version`+`entries[]`, BLAKE3 hash strict), `migration` (RFC-004 v1 frozen fields). RFC-002 v2-additive fields (`reversibility`, `blast_radius`, `contract_tests`, `success_criteria`, `verification_artifacts`) remain permissive while Draft. Top-level `additionalProperties: true` preserved (SPEC.md §33.7). Coexists with the preview schema — does NOT supersede it. |
 
 **Use this split form** when you need to validate the envelope *before* decryption and the payload *after* decryption as two independent steps (typical of secure decoders that fail-fast on the envelope).