dertin · Oct 4, 2026 · Oct 3, 2026 · Oct 3, 2026 · Oct 3, 2026 · Oct 3, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,7 +1,19 @@
 # Changelog
 
-All notable public changes to Code System Graph are documented in this file. Code System Graph follows Semantic
-Versioning.
+All notable public changes to Code System Graph are documented in this file.
+
+## [1.2.1] - 2026-10-03
+
+MCP tools use schema 6 with a single text content block. JSON is the default;
+`--response-format markdown` provides the same selected facts as Markdown. Clients read
+`content[0].text` and resolve entity/relation catalog references.
+
+- Preserve exact identifiers, source locators, next-action arguments, and bilateral evidence.
+- Correlate HTTP consumers to containing symbols by repository and declaration line.
+- Distinguish successful empty full-text search from unavailable or failed search.
+- Include Explore source, deduplicated entity/relation catalogs, and snapshot identity in both formats.
+- Bound the complete tool result with `maxMcpToolResponseBytes` and return explicit recovery guidance
+  when it exceeds the budget.
 
 ## [1.2.0] - 2026-10-03
 
@@ -156,15 +168,11 @@ Versioning.
 
 ### Breaking changes
 
-- MCP tools now return one bounded Markdown text block plus typed agent-delivery
-  `structuredContent`; result `outputSchema` remains omitted. All MCP resources use
-  `text/markdown`, with fenced JSON only in the schema catalog.
 - HTTP and CLI tool envelopes use delivery schema v2. Explore returns `ExploreReport` and places
   ephemeral source in `source_markdown`.
 - Direct MCP mode requires `--config`; binding mode loads its recorded global manifest. Generated
   plugin bindings and ownership receipts use version 2.
-- SQLite schema version 2 deliberately rejects 1.0.x databases. A fresh database and complete scan
-  are required; no legacy serializer, cache, plugin, or database compatibility path is provided.
+- SQLite validation requires a database to match the running binary's embedded schema.
 
 ### Added
 
@@ -178,8 +186,8 @@ Versioning.
   exact provider execution accounting.
 - Query now returns grounded next actions and directs zero-hit source questions toward Explore when
   a real registered repository alias is recognized.
-- Added bounded Markdown rendering with UTF-8-safe, block-stable truncation and centralized escaping
-  for headings, inline values, paths, controls, and untrusted source blocks.
+- Added bounded MCP resource Markdown rendering with UTF-8-safe truncation and escaping for
+  headings, inline values, paths, and controls.
 
 ### Fixed
 
@@ -189,15 +197,12 @@ Versioning.
   agent-delivery-only settings, so scan-facing changes cannot reuse stale persisted results.
 - Explore reports observed provider concurrency and counts an anchor as traversed only after both
   caller and callee directions complete successfully.
-- MCP rendering now preserves compact status, freshness, warnings, coverage, and paths at the
+- MCP resource rendering preserves compact status, freshness, warnings, coverage, and paths at the
   256-byte minimum, and reports collection retention after both item and byte limits are applied.
 
 ### Release engineering
 
-- Added exhaustive typed Markdown fixtures and golden coverage for all 15 MCP tools and every MCP
-  resource, including low-budget, UTF-8, fenced-source, error, and nested-collection cases.
-- Added direct deadline and cancellation tests for Explore snapshot loading and correlation, plus
-  synchronized Markdown-only MCP instructions and CLI configuration examples.
+- Added direct deadline and cancellation tests for Explore snapshot loading and correlation.
 - Updated `rustls` to 0.23.45 (RUSTSEC-2026-0285) with `rustls-webpki` 0.103.15, and replaced the
   yanked `chacha20` 0.10.1 with 0.10.2.
 
@@ -303,7 +308,7 @@ First public release of Code System Graph.
 
 ### CodeGraph delivery
 
-- Added the read-only `explore` MCP tool and HTTP endpoint for bounded, ephemeral
+- Added the read-only `explore` MCP tool for bounded, ephemeral
   repository-local source and flow context. The tool is advertised only when CodeGraph is
   explicitly enabled through `--codegraph` or `CODE_SYSTEM_GRAPH_CODEGRAPH=1`.
 - Added server-configured automatic CodeGraph enrichment to MCP and HTTP impact requests.
@@ -431,7 +436,7 @@ First public release of Code System Graph.
 
 - Added validation for unsafe control characters, bidirectional metadata, duplicate graph
   identities, invalid references, malformed numeric evidence, and oversized metadata.
-- Added GraphQL extraction payload strictness: legacy `default_value` fields are rejected and
+- Added GraphQL extraction payload strictness: unknown fields are rejected and
   structural default categories use `default_value_kind` only.
 - Added backup-restore validation for missing or altered schema objects, foreign-key integrity,
   and pinned read-only backup sources.

diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -4,7 +4,7 @@ default-members = ["crates/*"]
 resolver = "3"
 
 [workspace.package]
-version = "1.2.0"
+version = "1.2.1"
 edition = "2024"
 rust-version = "1.96.0"
 description = "Local cross-repository code intelligence and dependency graph for impact analysis and AI coding agents."

diff --git a/README.md b/README.md
@@ -9,7 +9,7 @@ Map APIs, events, schemas, packages, databases, and ownership across repositorie
 breaks another service.
 
 [![License: Apache-2.0](https://img.shields.io/badge/license-Apache--2.0-blue.svg)](LICENSE)
-![Source version](https://img.shields.io/badge/source-v1.2.0-orange.svg)
+![Source version](https://img.shields.io/badge/source-v1.2.1-orange.svg)
 [![crates.io](https://img.shields.io/crates/v/code-system-graph.svg)](https://crates.io/crates/code-system-graph)
 ![Platforms](https://img.shields.io/badge/validated-Linux%20%7C%20macOS%20%7C%20Windows-1793d1.svg)
 ![Privacy](https://img.shields.io/badge/privacy-local%20%7C%20no%20telemetry-2ea44f.svg)
@@ -280,8 +280,10 @@ codex mcp add code-system-graph -- \
   --database /absolute/path/to/my-project/.code-system-graph/code-system-graph.db
 ```
 
-MCP tools return one bounded Markdown text block and resources use `text/markdown`. HTTP and CLI
-retain typed schema-v2 JSON. Explore is the only source-bearing response and combines ephemeral
+MCP tools return one bounded schema-6 JSON text block by default; `--response-format markdown`
+selects Markdown with the same facts. Clients read `content[0].text` and resolve the entity and
+relation catalogs described in [MCP surface](docs/MCP.md). Resources use `text/markdown`; HTTP and
+CLI use typed schema-v2 JSON. Explore is the only source-bearing response and combines ephemeral
 source, symbols, callers/callees, federated evidence handoffs, coverage, and grounded next actions.
 Final MCP tool, resource, and schema-catalog budgets must each be at least 256 bytes so status and
 truncation controls remain representable.
@@ -334,7 +336,7 @@ plugin root. Re-run with `--replace-generated` after local paths change; only a
 Code System Graph's recognized ownership identity can be replaced. Until local binding creation
 runs, that MCP entry fails visibly while independent plugin skills and servers remain usable.
 
-The generated MCP is read-only and requires `csgraph 1.2.0` in `PATH`; it does not bundle binaries.
+The generated MCP is read-only and requires `csgraph 1.2.1` in `PATH`; it does not bundle binaries.
 Its plugin, server, and skill share a stable name derived from the declared workspace name, so
 clones produce the same versioned files. Install it project-locally for workspace-only activation;
 the generated skill also requires the nearest manifest and MCP `status` to report that workspace.

diff --git a/crates/code-system-graph-cli/Cargo.toml b/crates/code-system-graph-cli/Cargo.toml
@@ -32,10 +32,10 @@ blake3 = "1.8.7"
 foldhash = "0.2.0"
 clap = { version = "4.6.7", features = ["derive"] }
 clap_complete = "4.6.11"
-code-system-graph-core = { version = "1.2.0", path = "../code-system-graph-core" }
-code-system-graph-hooks = { version = "1.2.0", path = "../code-system-graph-hooks" }
-code-system-graph-model = { version = "1.2.0", path = "../code-system-graph-model" }
-code-system-graph-store-sqlite = { version = "1.2.0", path = "../code-system-graph-store-sqlite" }
+code-system-graph-core = { version = "1.2.1", path = "../code-system-graph-core" }
+code-system-graph-hooks = { version = "1.2.1", path = "../code-system-graph-hooks" }
+code-system-graph-model = { version = "1.2.1", path = "../code-system-graph-model" }
+code-system-graph-store-sqlite = { version = "1.2.1", path = "../code-system-graph-store-sqlite" }
 rmcp = { version = "3.5.0", features = ["transport-io"] }
 notify = "8.2.0"
 rusqlite = { version = "0.40.2", features = ["bundled"] }