# New Exec Type > Add a new executable type to the flow runner (a new kind of automation block users can define in .flow files). Use when this capability is needed. - Skill: `tomevault-io/new-exec-type` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/new-exec-type` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/new-exec-type/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/new-exec-type --- Add a new executable type to the flow runner for: $ARGUMENTS An "executable type" is a new automation block users can declare in `.flow` files (like `exec`, `serial`, `parallel`, `render`). Follow these steps in order: 1. **Schema first** — add the new type's fields to `types/executable/schema.yaml`. Read the existing schema to match the structure. Run `flow generate` to regenerate `types/executable/generated.go`. 2. **Runner handler** — create `internal/runner/.go` implementing the runner interface. Read `internal/runner/exec.go` or `internal/runner/serial.go` as reference for the exact interface and pattern. 3. **Register the type** — wire the new handler into `internal/runner/runner.go` (the dispatch table). 4. **Parser support** — update `internal/fileparser/` if needed to recognize and validate the new type during YAML parsing. 5. **Tests** — add unit tests in `internal/runner/_test.go` using Ginkgo. Use `Describe`/`It`/`Entry` — never `FDescribe`/`FIt`. Cover happy path and error cases. 6. **Validate** — run `flow validate` to confirm generate, lint, and tests all pass. Do not skip the schema step — editing generated files directly will cause CI to fail. --- > Source: [flowexec/flow](https://github.com/flowexec/flow) — distributed by [TomeVault](https://tomevault.io).