lynxai-team/agent-smith/create-agent

Create an Agent in YAML

Define, register, and verify an AI agent from a YAML file in the Agent Smith framework.

Workflow

1. Ensure a registered features directory (first time only) — edit the conf file to add your features/ root path, then run lm conf. The conf file lists the directories the framework scans for feature files; it is the source of truth for feature paths.
2. Write the agent YAML — create <name>.yml in features/agents/. The filename becomes the agent's default name (e.g., my-agent.yml → agent my-agent). Fill in the required fields (description, prompt, model) plus any optional ones from the field reference below.
3. Register — run lm update. This triggers feature discovery: it scans registered directories, parses agent metadata, and upserts into the agent SQLite table (and creates ToolSpec entries in the tool table).
4. (Optional) Expose as a subagent — add a tool: section to the YAML so other agents can call it, then run lm update again.
5. Verify:

lm agents                    # agent appears in the list
lm my-agent "Hello"           # runs the agent interactively

Field reference

Required: name (from filename), prompt (system prompt template; {prompt} = user input), description, model (e.g., qwen4b).

Optional: category (UI navigation), template (system prompt, stop sequences), inferParams (sampling: temperature, top_p, top_k, min_p, repetition_penalty), variables (input variable definitions with required:/optional:), toolsList (references to registered tools by name), tools (inline tool definitions), models (alternative models for UI selection), shots (few-shot examples), skills, workflow (pre/post steps), mcp.

Examples

Minimal agent:

description: "My first agent"
category: myagents/general
prompt: |-
    User query: {prompt}
model: qwen4b

Full annotated example:

# features/agents/my-coder.yml
description: "A coding agent with file and shell access"
category: development/coding
prompt: |-
    {prompt}
template:
    system: |-
      You are a coding agent. Follow instructions precisely.
      Report back with a short summary when done.
model: qwen35b
inferParams:
    min_p: 0
    top_k: 20
    top_p: 0.85
    temperature: 0.6
    repetition_penalty: 1
variables:
  required:
    workspace:
      description: The local directory path where to operate
toolsList:
  - read-file
  - write-file
  - edit-search-replace
  - shell

Subagent (callable by other agents) — add a tool: section defining the interface:

# features/agents/my-search.yml
tool:
  name: my-search
  description: Perform web search and return results
  arguments:
    prompt:
      description: The search query or question
      required: true
description: "A web search agent"
prompt: |-
    Research the following: {prompt}
model: qwen4b
toolsList:
  - ddsearch
  - openpage

Other agents reference it by its tool name in their toolsList (e.g., - my-search), then run lm update.

Gotchas

• Simply running lm conf without first editing the conf file will NOT add a new features directory — the conf file is the source of truth for feature paths.
• Every change to an agent's tool list requires re-registration: after adding, removing, or modifying entries in toolsList (or inline tools), run lm update again — the agent will not see new tools until then.
• A subagent is NOT usable until registered: the tool: section only defines the interface; lm update creates the ToolSpec entry in the tool table that makes it callable. Without this step, parent agents referencing it in their toolsList get a "tool not found" error.
• Renaming the YAML file changes the agent's default name — keep filenames stable or update references in other agents' toolsList.

References (load when needed)

• Full schema and field-by-field guide: agent-smith/docsite/public/doc/reference/1.howto-agents.md
• Minimal example agent: agent-smith/examples/features/agents/general-agent.yml
• Complex real-world example with template, variables, tools: lynx-coder/dist/agents/lx-coder.yml
• Feature discovery pipeline internals: agent-smith/docsite/public/doc/libraries/core/3.feature-discovery.md