diff --git a/.yoi/tickets/00001KWF2210A/item.md b/.yoi/tickets/00001KWF2210A/item.md
index ba8cce6b..7c6e43e4 100644
--- a/.yoi/tickets/00001KWF2210A/item.md
+++ b/.yoi/tickets/00001KWF2210A/item.md
@@ -1,8 +1,8 @@
 ---
 title: 'Workspace Backend設定ファイルのスキーマを定義する'
-state: 'done'
+state: 'closed'
 created_at: '2026-07-01T14:41:48Z'
-updated_at: '2026-07-01T15:48:17Z'
+updated_at: '2026-07-01T15:48:28Z'
 assignee: null
 queued_by: 'yoi ticket'
 queued_at: '2026-07-01T15:32:38Z'
diff --git a/.yoi/tickets/00001KWF2210A/resolution.md b/.yoi/tickets/00001KWF2210A/resolution.md
new file mode 100644
index 00000000..11b65c96
--- /dev/null
+++ b/.yoi/tickets/00001KWF2210A/resolution.md
@@ -0,0 +1,20 @@
+Implemented Workspace Backend config file schema and resolver.
+
+Delivered:
+- `WorkspaceBackendConfigFile` TOML schema with `server`, `data`, `limits`, and `runtimes.remote` sections.
+- Fixed workspace-local config path `.yoi/workspace-backend.local.toml`.
+- Defaults when config file is absent.
+- Unknown-field rejection.
+- Workspace-root relative path resolution and absolute path preservation.
+- Resolved config boundary for `ServerConfig`, listen address, and database path.
+- Data root derivation for `workspace.db` and `embedded-runtime`.
+- Secret value exclusion from schema; `token_ref` fails closed until secret ref resolution is implemented.
+- `yoi-workspace-server serve` loads config and applies only existing legacy dev CLI overrides.
+- Focused tests for defaults, unknown fields, path handling, data overrides, and secret field behavior.
+
+Validation:
+- `cargo test -p yoi-workspace-server`
+- `cargo check -p yoi`
+- `cargo fmt --check`
+- `git diff --check`
+- `nix build .#yoi --no-link`
diff --git a/.yoi/tickets/00001KWF2210A/thread.md b/.yoi/tickets/00001KWF2210A/thread.md
index fea08131..f9ed1f31 100644
--- a/.yoi/tickets/00001KWF2210A/thread.md
+++ b/.yoi/tickets/00001KWF2210A/thread.md
@@ -92,4 +92,41 @@ Validation:
 State changed to `done`.
 
 
+---
+
+<!-- event: state_changed author: hare at: 2026-07-01T15:48:28Z from: done to: closed reason: closed field: state -->
+
+## State changed
+
+Ticket を closed にしました。
+
+
+---
+
+<!-- event: close author: hare at: 2026-07-01T15:48:28Z status: closed -->
+
+## 完了
+
+Implemented Workspace Backend config file schema and resolver.
+
+Delivered:
+- `WorkspaceBackendConfigFile` TOML schema with `server`, `data`, `limits`, and `runtimes.remote` sections.
+- Fixed workspace-local config path `.yoi/workspace-backend.local.toml`.
+- Defaults when config file is absent.
+- Unknown-field rejection.
+- Workspace-root relative path resolution and absolute path preservation.
+- Resolved config boundary for `ServerConfig`, listen address, and database path.
+- Data root derivation for `workspace.db` and `embedded-runtime`.
+- Secret value exclusion from schema; `token_ref` fails closed until secret ref resolution is implemented.
+- `yoi-workspace-server serve` loads config and applies only existing legacy dev CLI overrides.
+- Focused tests for defaults, unknown fields, path handling, data overrides, and secret field behavior.
+
+Validation:
+- `cargo test -p yoi-workspace-server`
+- `cargo check -p yoi`
+- `cargo fmt --check`
+- `git diff --check`
+- `nix build .#yoi --no-link`
+
+
 ---