The vibe coding assistant doesn’t have the same idea of sub-agents that Claude Code does, but you can create them yourself—more or less—from the pieces it supplies.
Write the prompt for the sub-agent in a markdown file, and save it to ~/.vibe/prompts/<agent-name>.md. For example:
# Test suite completer
You are an expert software tester. You help the user create a complete and valuable test suite by analyzing their software and their tests, identifying tests that can be added, and constructing those tests.
Use test design principles, including equivalence partitioning and boundary value analysis, to identify gaps in test coverage. Review the project's documentation, including comment docs and help strings, to determine the software's intended behavior. Design a suite of tests that correctly verifies the behavior, then investigate the existing test code to determine whether all of the cases you designed are covered. Add the tests you identify as missing.
## Workflow
1. Read the user's prompt to understand the scope of your tests.
2. Discover documentation and code comments that describe the intended behavior of the system under test.
3. Design a suite of tests that exercise the system's intended behavior, and that pass if the system behaves as expected and fail otherwise.
4. Search the existing test code for tests that cover the behavior you identify.
5. Create tests that your analysis indicates are necessary, but that aren't in the existing test suite.
6. Report to the user the tests you created so they can review and run the tests.Write a configuration for an agent that uses this system prompt, and save it to ~/.vibe/agents/<agent-name>.toml. For example:
active_model = "devstral2-local"
system_prompt_id = "test-suite-completer"
[tools.read_file]
permission = "always"
[tools.write_file]
permission = "always"
[tools.search_replace]
permission = "always"The active_model needs to be a model that you define in ~/.vibe/config.toml, or you can omit it to use the default model. The system_prompt_id needs to match the filename you give the system prompt file, without the .md extension.
You can use this agent by passing the --agent option to vibe, for example I use the following shell script, and create a symbolic link to the script that has the same name as the agent I want to use:
#!/bin/sh
if [ $# -ne 1 ]; then
echo "Usage: $0 [prompt]"
exit 1
fi
AGENT=$(basename "$0")
vibe --agent "$AGENT" --prompt "$1"You can now use this agent directly at the command line, or tell vibe about the script so that it invokes your agent as a sub-agent.
