devo

devo is a CLI tool that generates tmux session shell commands from a small YAML DSL and runs them via bash. The name "devo" comes from "dev orchestrator".

quick start

nix develop
make build
make plan

Run:

make run

dsl

The default config file is devo.yaml. Main keys:

• session: tmux session name
• hook_session_closed: session-closed hook command
• inherit_env: list of environment variable names to snapshot once and source before each pane command
• tasks: task definitions
  • id: task id
  • pane: root / right_of:<task-id> / down_of:<task-id>
  • cmd: command(s) executed in that pane (string or string[])
• focus: task id to focus at the end

examples

simple example

devo.yaml:

session: demo-simple
focus: editor

tasks:
  - id: editor
    pane: root
    cmd: nvim

  - id: logs
    pane: right_of:editor
    cmd: tail -f /var/log/system.log

Layout result (conceptual):

+-------------------------+-------------------------+
| editor (root)           | logs (right_of:editor) |
| nvim                    | tail -f ...             |
+-------------------------+-------------------------+

Generated command flow (simplified):

new-session -> capture root pane id
editor uses root pane
split right from editor -> logs pane
send-keys to editor and logs
select-pane editor

advanced example

devo.yaml:

session: $SESSION_NAME
hook_session_closed: run-shell 'devo dev-stop'
focus: backend
inherit_env:
  - DEV_CMD
  - DEV_FRONTEND
  - DEV_KINTONE_JS
  - BIND_IP
  - COMPOSE_PROJECT_NAME

tasks:
  - id: backend
    pane: root
    cmd: $DEV_CMD make start-backend-dev

  - id: repl
    pane: right_of:backend
    cmd:
      - $DEV_CMD make -C backend repl NREPL_HOST='${BIND_IP}'
      - (go)

  - id: frontend
    pane: down_of:backend
    cmd: $DEV_CMD $DEV_FRONTEND

  - id: kintone_js
    pane: down_of:frontend
    cmd: $DEV_CMD $DEV_KINTONE_JS

  - id: compose
    pane: down_of:repl
    cmd: env UID=$(id -u) GID=$(id -g) HOST_IP='${BIND_IP}' docker compose -p $COMPOSE_PROJECT_NAME up

Layout result (conceptual):

+-----------------------------+-----------------------------+
| backend (root)              | repl (right_of:backend)    |
| make start-backend-dev      | make -C backend repl       |
+-----------------------------+-----------------------------+
| frontend (down_of:backend)  | compose (down_of:repl)     |
| $DEV_FRONTEND               | docker compose up           |
+-----------------------------+-----------------------------+
| kintone_js (down_of:front.) |                             |
| $DEV_KINTONE_JS             |                             |
+-----------------------------+-----------------------------+

Execution ordering rules:

1) pane dependency: right_of/down_of requires its base pane task
2) if multiple tasks are available, file order is preserved

commands

cargo run -- plan -f devo.yaml
cargo run -- run -f devo.yaml
cargo run -- run --session my-worktree -f devo.yaml
cargo run -- run --attach-or-create --session my-worktree -f devo.yaml
cargo run -- status --json --session my-worktree -f devo.yaml
cargo run -- stop --session my-worktree -f devo.yaml

plan prints the generated shell script, and run executes it with bash.

--session overrides the session value from devo.yaml. This is intended for external tools that need to choose deterministic tmux session names per worktree or task.

--attach-or-create attaches to an existing session when it exists. If it does not exist, devo creates it from the config and attaches afterward.

status --json reports whether the tmux session exists, the configured tasks, and the current tmux panes. Devo stores each task id in the pane-local tmux option @devo_task_id when creating panes, so external tools can correlate panes with tasks.