config.yaml schema

Every block in the tree — root or subblock — has a config.yaml with the same top-level shape. Live state is not stored here; that lives in artifacts/index.yaml.

Top-level structure

meta_info:
  name:                 # short identifier, kebab-case
  label:                # human-friendly title
  description:          # one-sentence purpose
  parent:               # parent block's `name`, or null for the root
  subblocks:            # one entry per child block (optional)
    <child_name>:
      role:             # one-line purpose of the child
      dependencies:     # input wiring — see "Wiring rule" below
        <input_key>: <source_block>.output.<key>     # or: human
  repos: {}             # name → {commit_id, role}; pinned vendored deps under repos/
  resources:
    ip:                 # 'local' (default) or null = current host; remote IP = SSH+tmux
    directory:          # working directory on the remote node (when ip is remote)

runtime_info:
  input: {}             # ONLY values originating outside the block tree
  output: {}            # values produced for downstream blocks

evolving:
  tunable_params: {}    # auto-tuned parameters with bounds (optional)

Wiring rule

This is the rule the whole pipeline depends on:

Inter-block values go in meta_info.subblocks[].dependencies, never in runtime_info.input. Only values originating outside the block tree go in runtime_info.input.

That keeps every path/handle that connects two blocks resolvable at preflight time — and means you never copy paths by hand. /root:check validates that every subblocks[].dependencies entry resolves to a non-null output of the named sibling.

runtime_info.input vs runtime_info.output

• input is what you (or another tool) must fill before the block can run. Examples: API keys, GitHub tokens, human decisions about model names.
• output is what the block promises to publish once it has run. Examples: a directory of verified tasks, a checkpoint path. Downstream blocks reference these via dependencies.

resources.ip

• local or null → run on the current host (default; no SSH).
• Real remote IP → the agent must SSH into that node and run inside a tmux session, with meta_info.resources.directory as the working directory.

Do not "restore" an old remote IP from git history. The local default is intentional.

evolving.tunable_params

Optional. When set, the orchestrator may adjust these within bounds across runs as part of the self-evolving loop. Leave empty if the block is not tuned.

Where to read more

• The canonical contract: .claude/plugins/root-plugin/resources/BLOCK_DEFINITION.md.
• A worked example scaffold: .claude/plugins/root-plugin/references/example_block/.