mthds-build

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Translated

Build new AI method from scratch using the MTHDS standard (.mthds bundle files). Use when user says "create a pipeline", "build a workflow", "new .mthds file", "make a method", "design a pipe", or wants to create any new method from scratch. Guides the user through a 10-phase construction process.

3installs

Sourcemthds-ai/skills

Added on2026-02-27

NPX Install

npx skill4agent add mthds-ai/skills mthds-build

SKILL.md Content

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Build AI Method using the MTHDS standard (Agentic)

Create new MTHDS bundles through an adaptive, phase-based approach. This skill guides you through drafting (markdown), structuring (CLI/JSON), and assembling complete .mthds bundles.

Philosophy

Drafting phases: Generate human-readable markdown documents
Structuring phases: Use agent CLI commands for JSON-to-TOML conversion
Visualization: Present ASCII graphs at overview and detail levels
Iterative: Refine at each phase before proceeding

Mode Selection

How mode is determined

Explicit override: If the user states a preference, always honor it:
- Automatic signals: "just do it", "go ahead", "automatic", "quick", "don't ask"
- Interactive signals: "walk me through", "help me", "guide me", "step by step", "let me decide"
Skill default: Each skill defines its own default based on the nature of the task.
Request analysis: If no explicit signal and no strong skill default, assess the request:
- Detailed, specific requirements → automatic
- Brief, ambiguous, or subjective → interactive

Mode behavior

Automatic mode:

State assumptions briefly before proceeding
Make reasonable decisions at each step
Present the result when done
Pause only if a critical ambiguity could lead to wasted work

Interactive mode:

Ask clarifying questions at the start
Present options at decision points
Confirm before proceeding at checkpoints
Allow the user to steer direction

Mode switching

If in automatic mode and the user asks a question or gives feedback → switch to interactive for the current phase
If in interactive mode and the user says "looks good, go ahead" or similar → switch to automatic for remaining phases

Default: Automatic for simple-to-moderate methods. Interactive for complex multi-step methods or when the user's request is ambiguous.

Detection heuristics:

User provides a clear one-sentence goal → automatic
User describes a complex multi-step process → interactive
User mentions batching, conditions, or parallel execution → interactive
User says "create a pipeline for X" with no elaboration → automatic

Step 0 — CLI Check (mandatory, do this FIRST)

Run

mthds-agent --version

If it succeeds: proceed to the next step.
If it fails or the command is not found: STOP. Do not proceed with this skill. Tell the user:

The
mthds-agent
CLI is required but not installed. Install it with:
npm install -g mthds
Then re-run this skill.

Do not write

.mthds

files manually, do not scan for existing methods, do not do any other work. The CLI is required for validation, formatting, and execution — without it the output will be broken.

Existing Method Detection

Goal: Before starting a new build, check whether the project already contains methods that overlap with the user's request.

When to check: Always, before entering automatic or interactive mode — with these exceptions:

Skip entirely if the user's request signals intent to create something new. This includes phrases like "new method", "a new method", "brand new", "from scratch", "create a method", or similar.
Targeted search if the user references a specific existing method by name or path, search specifically for that method instead of scanning broadly. If the specific method cannot be found, fall back to the general search approach below.

For the general case, scan

mthds-wip/

and any other directories containing

.mthds

files in the project.

How to check:

List all
```
.mthds
```
files in the project (glob for
```
**/*.mthds
```
)
For each file found, read the file header (domain, main pipe code, description) to understand what it does
Compare with the user's current request — look for overlap in topic, domain, or purpose

If no existing methods overlap: Proceed normally with the build.

If one or more existing methods overlap, present the user with three options:

I found an existing method that seems related to what you're asking for:
<path/to/bundle.mthds>
— <brief description of what it does>
How would you like to proceed?

Start fresh — Create a wholly new method from scratch (ignoring the existing one)

Use the existing method — It already does what you need; cancel this build

Build upon it — Extend the existing method by adding pipes before or after the current flow

Handling each choice:

Start fresh: Proceed with the build as normal (automatic or interactive path below).
Use the existing method: End the build. Remind the user they can run it with
```
/mthds-run
```
and point them to its
```
inputs.json
```
if available.
Build upon it: Switch to the /mthds-edit skill, framing the task as an extension — ask the user what additional processing they want to add (e.g., a preprocessing step before the main pipe, a postprocessing step after, or additional parallel branches). Pass the existing
```
.mthds
```
file path to the edit workflow.

Phase 1: Understand Requirements

Goal: Gather complete information before planning.

Ask the user:

What are the method's inputs? (documents, images, text, structured data)
What outputs should it produce?
What transformations are needed?
Are there conditional branches or parallel operations?
Should items be processed in batches?

Output: Requirements summary (keep in context)

Phase 2: Draft the Plan

Goal: Create a pseudo-code narrative of the method.

Draft a plan in markdown that describes:

The overall flow from inputs to outputs
Each processing step with its purpose
Variable names (snake_case) for inputs and outputs of each step
Where structured data or lists are involved

Rules:

Name variables consistently across steps
Use plural names for lists (e.g.,
```
documents
```
), singular for items (e.g.,
```
document
```
)
Don't detail types yet - focus on the flow

Show ASCII Overview — see Manual Build Phases for the diagram template.

Output: Plan draft (markdown)

Phase 3: Draft Concepts

Goal: Identify all data types needed in the method.

From the plan, identify input, intermediate, and output concepts.

For each concept, draft:

Name: PascalCase, singular noun (e.g.,
```
Invoice
```
not
```
Invoices
```
)
Description: What it represents
Type: Either
```
refines: NativeConcept
```
OR
```
structure: {...}
```

Native concepts (built-in, do NOT redefine):

Text

Html

Image

Document

Number

Page

TextAndImages

ImgGenPrompt

JSON

Anything

Dynamic

. See MTHDS Language Reference — Native Concepts

Note:
Document
is the native concept for any document (PDF, Word, etc.).
Image
is for any image format (JPEG, PNG, etc.). File formats like "PDF" or "JPEG" are not concepts.

Each native concept has accessible attributes (e.g.,

Image

has

url

public_url

filename

caption

...;

Document

has

url

public_url

filename

...;

Page

has

text_and_images

and

page_view

). See Native Content Types for the full attribute reference — essential for

$var.field

prompts and

construct

blocks.

Concept naming rules:

No adjectives:
```
Article
```
not
```
LongArticle
```
No circumstances:
```
Argument
```
not
```
CounterArgument
```
Always singular:
```
Employee
```
not
```
Employees
```

Output: Concepts draft (markdown)

Phase 4: Structure Concepts

Goal: Convert concept drafts to validated TOML using the CLI.

Prepare JSON specs for all concepts, then convert them in parallel by making multiple concurrent tool calls.

Example (3 concepts converted in parallel):

bash

# Call all three in parallel (single response, multiple tool calls):
mthds-agent pipelex concept --spec '{"the_concept_code": "Invoice", "description": "A commercial invoice document", "structure": {"invoice_number": "The unique identifier", "vendor_name": {"type": "text", "description": "Vendor name", "required": true}, "total_amount": {"type": "number", "description": "Total amount", "required": true}}}'
mthds-agent pipelex concept --spec '{"the_concept_code": "LineItem", "description": "A single line item on an invoice", "structure": {"description": "Item description", "quantity": {"type": "integer", "required": true}, "unit_price": {"type": "number", "required": true}}}'
mthds-agent pipelex concept --spec '{"the_concept_code": "Summary", "description": "A text summary of content", "refines": "Text"}'

Field types:

text

integer

boolean

number

date

concept

list

Choices (enum-like constrained values):

toml

status = {choices = ["pending", "processing", "completed"], description = "Order status", required = true}
score = {type = "number", choices = ["0", "0.5", "1", "1.5", "2"], description = "Score on a half-point scale"}

When

choices

is present,

type

defaults to

text

if omitted. You can also pair choices with

integer

number

types explicitly.

Nested concept references in structures:

toml

field = {type = "concept", concept_ref = "my_domain.OtherConcept", description = "...", required = true}
items = {type = "list", item_type = "concept", item_concept_ref = "my_domain.OtherConcept", description = "..."}

Output: Validated concept TOML fragments

Partial failures: If some commands fail, fix the failing specs using the error JSON (
error_domain: "input"
means the spec is wrong). Re-run only the failed commands.

Phase 5: Draft the Flow

Goal: Design the complete pipeline structure with controller selection.

Controller Selection Guide

Controller	Use When	Key Pattern
PipeSequence	Steps must execute in order	step1 → step2 → step3
PipeBatch	Same operation on each list item	map(items, transform)
PipeParallel	Independent operations run together	fork → join
PipeCondition	Route based on data values	if-then-else

Operator Selection Guide

Operator	Use When
PipeLLM	Generate text or structured objects with AI
PipeExtract	Extract content from PDF/Image → Page[]
PipeCompose	Template text or construct objects
PipeImgGen	Generate images from text prompts
PipeFunc	Custom Python logic

Note:
Page[]
outputs from PipeExtract automatically convert to text when inserted into prompts using
@variable
.

Show detailed ASCII flow — see Manual Build Phases for all controller flow diagrams.

Output: Flow draft with pipe contracts (markdown)

Phase 6: Review & Refine

Goal: Validate consistency before structuring.

Check:

Main pipe is clearly identified and handles method inputs
Variable names are consistent across all pipes
Input/output types match between connected pipes
PipeBatch branches receive singular items, not lists
PipeBatch:
```
input_item_name
```
(singular) differs from
```
input_list_name
```
(plural) and all
```
inputs
```
keys
PipeSequence batch steps:
```
batch_as
```
(singular) differs from
```
batch_over
```
(plural)
PipeImgGen inputs are text (add PipeLLM if needed to generate prompt)
No circular dependencies

Confirm with user before proceeding to structuring.

Phase 7: Structure Pipes

Goal: Convert pipe drafts to validated TOML using the CLI.

Default to talent names from Talents and Presets. Only look up specific model presets when the user has explicit instructions about model choice. In all cases, verify that referenced presets exist:

bash

mthds-agent pipelex models --type llm          # when structuring PipeLLM pipes
mthds-agent pipelex models --type extract      # when structuring PipeExtract pipes
mthds-agent pipelex models --type img_gen      # when structuring PipeImgGen pipes

Prepare JSON specs for all pipes, then convert them in parallel by making multiple concurrent tool calls.

For detailed CLI examples for each pipe type (PipeLLM, PipeSequence, PipeBatch, PipeCondition, PipeCompose, PipeParallel, PipeExtract, PipeImgGen), see Manual Build Phases.

Output: Validated pipe TOML fragments

Partial failures: Fix failing specs using the error JSON. Re-run only the failed commands.

Phase 8: Assemble Bundle

Goal: Combine all parts into a complete .mthds file.

Save location: Always save method bundles to

mthds-wip/

. Do not ask the user for the save location.

For the assemble CLI command and direct .mthds writing examples, see Manual Build Phases.

Phase 9: Validate & Test

Goal: Ensure the bundle is valid and works correctly.

Always use

-L

pointing to the bundle's own directory to avoid namespace collisions with other bundles in the project.

bash

# Validate (isolated from other bundles)
mthds-agent pipelex validate pipe mthds-wip/pipeline_01/bundle.mthds -L mthds-wip/pipeline_01/

# Generate example inputs
mthds-agent pipelex inputs pipe mthds-wip/pipeline_01/bundle.mthds -L mthds-wip/pipeline_01/

# Dry run (directory mode: auto-detects bundle, inputs, library dir)
mthds-agent pipelex run pipe mthds-wip/pipeline_01/ --dry-run --mock-inputs

Fix any validation errors and re-validate. If validation fails unexpectedly or errors are unclear, re-run with

--log-level debug

for additional context:

bash

mthds-agent --log-level debug pipelex validate pipe mthds-wip/pipeline_01/bundle.mthds -L mthds-wip/pipeline_01/

Phase 10: Deliver

Goal: Generate input template after a successful build.

After validation passes (Phase 9), generate the input template:

bash

# Input template (extracts the input schema as JSON)
mthds-agent pipelex inputs pipe <mthds_file> -L <output_dir>/

Replace

<mthds_file>

and

<output_dir>

with actual paths from the build output.

Present Results

After the command succeeds:

Input template: Show the
```
inputs
```
JSON from the inputs command output. Save it to
```
<output_dir>/inputs.json
```
for the user to fill in.
Next steps — try it now: If the method requires inputs, the saved
```
inputs.json
```
still contains placeholder values, so suggest a dry run first:
To try this method right now, use /mthds-run or from the terminal:
```
mthds run pipe <output_dir>/ --dry-run --mock-inputs
```
Next steps — run with real data: Explain how to prepare real inputs, then run for real:
To run with real data, use /mthds-inputs to prepare your inputs (provide your own files, or generate synthetic test data), then:
```
mthds run pipe <output_dir>/
```
Replace
```
<output_dir>
```
with the actual output directory path used throughout the build.

Quick Reference

Multiplicity Notation

```
Text
```
- single item
```
Text[]
```
- variable-length list
```
Text[3]
```
- exactly 3 items

Prompt Variables

```
@variable
```
- Block insertion (multi-line, with delimiters)
```
$variable
```
- Inline insertion (short text)
```
$var.field
```
- Access nested field

Naming Conventions

Domain:
```
snake_case
```
Concepts:
```
PascalCase
```
, singular
Pipes:
```
snake_case
```
Variables:
```
snake_case
```

Reference

Error Handling — read when CLI returns an error to determine recovery
MTHDS Agent Guide — read for CLI command syntax or output format details
MTHDS Language Reference — read when writing or modifying .mthds TOML syntax
Native Content Types — read when using
```
$var.field
```
in prompts or
```
from
```
in construct blocks, to know which attributes each native concept exposes
Manual Build Phases — read for detailed ASCII diagrams and CLI examples per phase
Talents and Presets — read when selecting model talents for pipe structuring

mthds-build

NPX Install

Tags

SKILL.md Content

Build AI Method using the MTHDS standard (Agentic)

Philosophy

Mode Selection

How mode is determined

Mode behavior

Mode switching

Step 0 — CLI Check (mandatory, do this FIRST)

Existing Method Detection

Phase 1: Understand Requirements

Phase 2: Draft the Plan

Phase 3: Draft Concepts

Phase 4: Structure Concepts

Phase 5: Draft the Flow

Controller Selection Guide

Operator Selection Guide

Phase 6: Review & Refine

Phase 7: Structure Pipes

Phase 8: Assemble Bundle

Phase 9: Validate & Test

Phase 10: Deliver

Present Results

Quick Reference

Multiplicity Notation

Prompt Variables

Naming Conventions

Reference