> ## Documentation Index > Fetch the complete documentation index at: https://docs.substrate.42.pe/llms.txt > Use this file to discover all available pages before exploring further. # Substrate-Edit MCP Tools: Boards, Groups, Policies > The 12 MCP tools for editing boards, groups, policies, and project settings. Changes take effect immediately — no migration, no restart. These twelve tools edit substrate-as-code — the same thing you could edit by hand in `.substrate/boards/.json`. Changes take effect on the next read: no migration step, no server restart required. All twelve require `agent_name`; all update and archive operations also require the current `version` of the entity you are changing. Reach for these tools to **extend** an existing board. Creating a second board that models the same flow is the most common way a substrate stops being a single source of truth. *** ## Project ### `update_project` Updates top-level project metadata. Send only the fields you are changing. The version from your last `get_project` read. A stable identifier for the calling agent. New project name. New project description. *** ## Boards ### `create_board` Creates a new board and returns it with its generated id. Board name. A stable identifier for the calling agent. Board description. Optional initial field schema. Validated structurally on creation. Project to create the board under. Defaults to the current project. ### `update_board` Updates a board's metadata or field schema. Send only what is changing. The board id. The version from your last read. A stable identifier for the calling agent. New board name. New board description. Replaces the entire field schema. Use `field_schema_patch` when changing one field. Merges into the existing schema key-by-key. Set a key to `null` to delete that field. Prefer this over `field_schema` when changing a single field. Schema changes never reject existing task data — validation is lazy. Existing tasks are not revalidated when you tighten a schema. `update_board` refuses to **downgrade** a `human_only` field. An agent can neither clear the `human_only` flag nor delete the field to escape a human gate. Both operations return `forbidden`. ### `archive_board` Soft-deletes a board. Idempotent. The board id. The version from your last read. A stable identifier for the calling agent. ### `unarchive_board` Restores an archived board. Idempotent. The board id. The version from your last read. A stable identifier for the calling agent. *** ## Groups ### `create_group` Creates a new group on a board. The board to add the group to. Group name. A stable identifier for the calling agent. Group description. Display position. Defaults to the next available slot. Display color for the group. ### `update_group` Updates a group's display properties. Send only the fields you are changing. The group id. The version from your last read. A stable identifier for the calling agent. New group name. New group description. New display position. New display color. Set to `null` to clear it. ### `reorder_groups` Reorders all groups on a board in one atomic write. You must supply every group id — partial lists are rejected. The board whose groups to reorder. The complete ordered list of group ids. Must be exactly the board's current group ids. A stable identifier for the calling agent. ### `archive_group` Archives a group. The group must have no active tasks — move them first. Idempotent once the group is already archived. The group id. The version from your last read. A stable identifier for the calling agent. If active tasks still reference the group, the tool returns `conflict`. Move or archive the tasks first, then retry. *** ## Policies ### `create_policy` Creates a policy on a board. The two policy types have different `definition` shapes. The board to add the policy to. Policy name. Policy class. Immutable after creation. The policy logic. Shape is validated against `type` — see below. A stable identifier for the calling agent. Human-readable explanation of what the policy does. Evaluation priority. Lower numbers run first. Defaults to `true`. Set to `false` to create a disabled policy. **Definition shapes:** `transition_guard` — Blocks a matching move unless every `require` condition passes. ```json theme={null} { "from_group": "", "to_group": "", "require": [{ "field": "task.tests_passing", "op": "eq", "value": true }], "on_failure_message": "Set tests_passing before moving to review." } ``` `agent_responsibility` — Never blocks. Attaches a `message` as a suggestion in the write envelope whenever `when` matches. An empty `when` matches every write. ```json theme={null} { "when": { "any_of": [{ "field": "task.group_id", "op": "eq", "value": "" }] }, "message": "Remember to update the changelog before shipping." } ``` Conditions are `{ field, op, value?, values? }` or a compound `{ all_of | any_of | none_of: Condition[] }`. Fields resolve literal-then-`custom_data`, so a custom gate field is referenced as `task.`. See [Authoring Policies](/authoring/write-policies) for the full grammar. ### `update_policy` Updates a policy. Send only the fields you are changing. The policy `type` is immutable — archive the policy and create a new one to change class. The policy id. The version from your last read. A stable identifier for the calling agent. New policy name. New description. Replacement definition. Re-validated against the policy's existing `type`. New evaluation priority. Enable or disable the policy. Policy `type` is immutable. To change a policy from `transition_guard` to `agent_responsibility` (or vice versa), archive the existing policy and create a new one. ### `archive_policy` Archives a policy. Idempotent. The policy id. The version from your last read. A stable identifier for the calling agent. Archiving a guard removes a rail. The action is git-visible and event-logged rather than silent — but an agent under pressure archiving the gate that blocks it is the residual risk in the model. *** ## After Editing Run `substrate validate` to check all board files for structural errors. Then prove the rail fires as expected: see [Validate Gates](/authoring/validate-gates).