Manifest Basics

Flo discovers tools and skills by file name:

• **/*.tool.yaml defines one tool
• **/*.skill.yaml defines one skill

SKILL.md discovery is not supported.

Tool Manifest Shape

Every tool manifest must include:

• name
• description
• input_schema
• execution

Optional fields include:

• timeout_ms
• retry_policy
• vault
• state

Example:

name: capture_example
description: Open a page and return the current URL.
input_schema:
  type: object
  properties:
    url:
      type: string
  required: [url]
  additionalProperties: false
execution:
  type: script
  script_file: scripts/capture_example.mts
  entrypoint: run
timeout_ms: 30000

Script Execution

For execution.type = script, define exactly one of:

• script: inline JavaScript or TypeScript
• script_file: a relative path under the manifest directory

Use entrypoint to select the exported function the runtime should call.

Skill Manifest Shape

Every skill manifest must include:

• skill_id
• name
• description

Each skill must define exactly one instruction source:

• instruction
• instruction_file

Optional fields include:

• version
• tools
• tool_definitions
• requires_skills

Example:

skill_id: browser_examples
name: Browser Examples
description: Browser-based tools for authenticated workflows.
tools:
  - read_text_file
tool_definitions:
  - name: capture_example
    description: Open a page and return the current URL.
    input_schema:
      type: object
      properties:
        url:
          type: string
      required: [url]
    execution:
      type: script
      script_file: scripts/capture_example.mts
      entrypoint: run
instruction_file: instructions.md

State and Vault Declarations

Use state when your script needs durable non-secret data:

state:
  - name: session_counter
    key_prefix: counter.session.
    scope_kind: session
  - name: shared_counter
    key_prefix: counter.shared.
    scope_kind: shared
    scope_id: service

Use vault when your script needs secrets:

vault:
  - key: api_token
    scope_kinds: [profile, shared]

The runtime still requires the script to fetch secrets explicitly through flo.vault.get(...).

Import Rules

The script runtime supports:

• local static ESM imports
• relative .mjs, .mts, and related local module paths

The runtime rejects:

• bare specifiers
• package-style imports
• dynamic import()
• .. traversal for author-facing asset imports

Next: TypeScript Runtime