lobu-builder

name	lobu-builder
description	Use when working inside a Lobu project generated by @lobu/cli or any repository centered on lobu.config.ts, AGENTS.md, agent prompt files, local skills, and evals. This skill helps a coding agent inspect the right files, make Lobu-native changes, keep the stack runnable, and validate behavior with chat tests and evals.

Lobu Builder

Overview

Use this skill when the repository is a Lobu project and the task is to build or change the agent itself: prompt files, lobu.config.ts, local skills, MCP configuration, connections, network settings, or evals.

If you are inside the Lobu monorepo rather than a generated Lobu project, follow that repository's own instructions first.

First Pass

1. Read AGENTS.md first. If it redirects to another file such as @TESTING.md, open that too.
2. Read lobu.config.ts. It is TypeScript: defineConfig from @lobu/cli/config is the default export.
3. Enumerate agent directories under agents/ and inspect the target agent's IDENTITY.md, SOUL.md, and USER.md.
4. Check whether the repo has shared skills/ or agent-local agents/<id>/skills/.
5. Look for evals under agents/<id>/evals/promptfooconfig.yaml (the project may also have legacy YAML files — those don't run).

Do not assume there is only one agent or one platform connection.

What To Edit

• IDENTITY.md: who the agent is
• SOUL.md: rules, workflows, guardrails
• USER.md: user or tenant context
• lobu.config.ts: providers, connections, enabled skills, MCP servers, network allowlist (authored with define* from @lobu/cli/config)
• skills/.../SKILL.md: shared reusable capabilities
• agents/<id>/skills/.../SKILL.md: agent-specific capabilities
• agents/<id>/evals/promptfooconfig.yaml: promptfoo eval suite (runs via bunx promptfoo eval with @lobu/promptfoo-provider)

Prefer editing these files directly instead of burying behavior in ad hoc code.

Workflow

1. Keep the project runnable. Start or reuse the stack with npx @lobu/cli@latest run -d.
2. Make the smallest prompt, config, skill, or eval change that solves the task.
3. Run npx @lobu/cli@latest validate after changing lobu.config.ts or skill definitions.
4. Test behavior with npx @lobu/cli@latest chat "..." or the project's testing instructions.
5. Run LOBU_TOKEN=$(npx @lobu/cli@latest token --raw) bunx promptfoo eval -c agents/<id>/evals/promptfooconfig.yaml when the behavior should be captured as a regression test.

If the repository already provides project-specific test scripts, use those.

Skills And MCP

• Prefer Lobu skills for reusable capabilities.
• For external data, prefer a small MCP surface over custom glue code.
• For MVP work, start with one MCP server and one skill.
• If per-user access matters, prefer MCP OAuth device authorization and let the gateway proxy handle authentication.
• Keep network access narrow; only add the domains the agent actually needs.

Useful Suggestions

• Add or reorder providers on defineAgent({ providers }) in lobu.config.ts
• Enable built-in skills with npx @lobu/cli@latest skills list, search, or add
• Add a custom MCP server via defineAgent({ mcpServers })
• Add a shared skill under skills/ for repeated workflows
• Add evals for risky behaviors and policy constraints
• Wire observability only when needed; Lobu supports Grafana/Tempo traces

References

• Getting started: https://lobu.ai/getting-started/
• Skills: https://lobu.ai/getting-started/skills/
• Skills authoring: https://lobu.ai/guides/skills-authoring/
• MCP proxy and device auth: https://lobu.ai/guides/mcp-proxy/
• Testing: https://lobu.ai/guides/testing/
• Evals: https://lobu.ai/guides/evals/
• Observability: https://lobu.ai/guides/observability/
• Repository: https://github.com/lobu-ai/lobu