Skills

Skills are instructional multi-step workflows embedded in a schema. Unlike Prompts (which explain context), Skills instruct — they tell an LLM exactly what to do, step by step. Each skill declares its tool dependencies, defines typed input parameters, and records the model it was tested with.

Tip

Skills vs Prompts: Use a Prompt when you want to provide context or explain a domain. Use a Skill when you want to orchestrate a repeatable multi-step workflow that calls specific tools in sequence.

Skill Execution Flow

How a skill is resolved and executed at runtime:

The skill’s content is a template. Placeholders like {{input:tokenSymbol}} are replaced with user-provided values, and {{tool:computeRSI}} references tell the LLM which tool to call at each step.

Defining Skills

Skills are declared in the main export’s skills key. Each entry points to a separate .mjs file:

export const main = {
    namespace: 'tradingsignals',
    name: 'TradingSignals',
    version: '3.0.0',
    root: 'https://api.example.com',
    tools: {
        computeRSI: { /* ... */ },
        computeMACD: { /* ... */ }
    },
    skills: {
        'token-technical-analysis': { file: './skills/token-technical-analysis.mjs' }
    }
}

Skill Reference Fields

Each key in main.skills is the skill name (must match ^[a-z][a-z0-9-]*$). The value is an object:

Field	Type	Required	Description
file	string	Yes	Path to the .mjs skill file, relative to the schema. Must end in .mjs.

Skill File Format

Each skill file exports a skill object with the full workflow definition:

const content = `Perform technical analysis of {{input:tokenSymbol}} on {{input:chain}}.

## Step 1: Token Discovery
Use {{tool:searchBySymbol}} to find {{input:tokenSymbol}} on {{input:chain}}.

## Step 2: OHLCV Data
Use {{tool:getRecursiveOhlcvEVM}} for {{input:timeframeDays}}-day candles.

## Step 3: Indicators
Use {{tool:computeRSI}} with period 14.
Use {{tool:computeMACD}} with fast 12, slow 26, signal 9.

## Step 4: Synthesis
Compile findings into BULLISH / BEARISH / NEUTRAL signal.`

export const skill = {
    name: 'token-technical-analysis',
    version: 'flowmcp-skill/1.0.0',
    description: 'Full technical analysis: discovery, OHLCV, indicators, chart, signal summary',
    testedWith: 'anthropic/claude-sonnet-4-5-20250929',
    requires: {
        tools: [
            'indicators/tool/searchBySymbol',
            'ohlcv/tool/getRecursiveOhlcvEVM',
            'tradingsignals/tool/computeRSI',
            'tradingsignals/tool/computeMACD'
        ],
        resources: [],
        external: [ 'playwright' ]
    },
    input: [
        { key: 'tokenSymbol', type: 'string', description: 'Token symbol (e.g. WETH)', required: true },
        { key: 'chain', type: 'string', description: 'Blockchain (e.g. ethereum)', required: true },
        { key: 'timeframeDays', type: 'number', description: 'Days of history', required: false }
    ],
    output: 'Structured report with trend, momentum, volatility, chart, and signal summary',
    content
}

Skill Object Fields

Field	Type	Required	Description
name	string	Yes	Must match the name in the schema’s skills array entry.
version	string	Yes	Must be 'flowmcp-skill/1.0.0'.
description	string	Yes	What this skill does.
testedWith	string	Yes	Model ID the skill was tested with (e.g. anthropic/claude-sonnet-4-5-20250929).
requires	object	Yes	Dependencies: tools, resources, and external arrays.
input	array	No	User-provided input parameters.
output	string	No	Description of what the skill produces.
content	string	Yes	The instruction text with placeholders.

Note

testedWith is required for Skills. Every skill must declare which model it was tested with. This is a key difference from Prompts, which do not require testedWith. The field records accountability — if a skill produces unreliable results, the tested model is the first variable to check.

requires Object

Field	Type	Description
tools	string[]	Tool references this skill uses. Uses the full ID format (namespace/tool/name) for cross-schema references, or plain names for same-schema tools.
resources	string[]	Resource names this skill reads. Must match names in main.resources.
external	string[]	External capabilities not provided by the schema (e.g. playwright, puppeteer). For documentation purposes.

Note

requires.external is Skills-only. Prompts do not have an external field. Use it to document dependencies that exist outside the FlowMCP ecosystem, so consumers know what additional setup is needed.

input Array

Each input parameter:

Field	Type	Description
key	string	Parameter name (camelCase). Referenced in content as {{input:key}}.
type	string	One of string, number, boolean, or enum.
description	string	What this input parameter is for.
required	boolean	Whether the user must provide this value.

Placeholder Syntax

The content field supports four placeholder types, identical to the Prompts placeholder system:

Placeholder	Syntax	Resolves To	Example
Tool reference	{{tool:name}}	Tool name from requires.tools	{{tool:computeRSI}}
Resource reference	{{resource:name}}	Resource name from requires.resources	{{resource:verifiedContracts}}
Skill reference	{{skill:name}}	Another skill in the same schema	{{skill:quick-check}}
Input reference	{{input:key}}	User-provided input value	{{input:tokenSymbol}}

Placeholder Rules

1. {{tool:x}} — x should be listed in requires.tools
2. {{resource:x}} — x should be listed in requires.resources
3. {{skill:x}} — must reference another skill in the same schema (no circular references)
4. {{input:x}} — should match an input[].key

Unresolved placeholders produce validation warnings (not errors), except for {{skill:x}} which must resolve.

Constraints

Constraint	Value	Rationale
Max skills per schema	4	Keep schemas focused
testedWith	Required	Accountability for non-deterministic workflows
requires.external	Skills-only	Prompts do not support this field
Skill name pattern	^[a-z][a-z0-9-]*$	Lowercase with hyphens
Skill file extension	.mjs	ES module format
Version	flowmcp-skill/1.0.0	Fixed for v3.0.0
Content	Non-empty string	Must contain instructions
No circular references	Via {{skill:x}}	Prevents infinite loops

Skills vs Prompts Summary

Aspect	Prompt	Skill
Purpose	Explain context	Instruct step-by-step
testedWith	Optional	Required
requires.external	Not available	Available
Placeholder system	Same	Same
Max per schema	4	4
File format	.mjs	.mjs
MCP primitive	Prompts	Prompts