Setup Custom Libraries

Register or update custom Simulink block libraries so the agent prefers them over built-in blocks during model building.

When to Use

• User asks to set up, register, add, or configure custom libraries
• User wants to add new .slx files to an existing library configuration
• User says "setup custom libraries", "add my library", "configure libraries", "add a new library file"
• building-simulink-models routes here via the policy gate

When NOT to Use

• Only configuring block exclusions or parameter protection (libraries already declared) → configuring-block-policy
• Only curating block descriptions/categories (libraries already declared) → curating-library-kg

Workflow

Do this FIRST and ALONE — no other tool calls in the same message.

Check all three files: .satk/reuse-libraries.json, .satk/block-policy.json, .satk/library-kg/index.md.

• All three exist → setup already complete. If they want to add new libraries, proceed to "Adding files" below.
• `.satk/reuse-libraries.json` exists with `confirmedNone: true` → no custom libraries configured. Ask the user if they want to change that. If not, setup is complete — skip Gates 2 and 3.
• Any missing → run gates sequentially:

Follow references/library-setup.md for all gate resolution details — it is the single source of truth for API calls, examples, and options at each gate.

Gate 1 — Library declaration: If .satk/reuse-libraries.json is missing, STOP and ask the user about reusable libraries. Do not read reference files, open models, or plan blocks until they respond. Gate 2 — Block policy: If .satk/block-policy.json is missing, STOP and ask the user about policy setup by following references/library-setup.md. Do not proceed until policy is resolved. Gate 3 — Library blocks knowledge index: If .satk/library-kg/index.md is missing, STOP and ask the user whether to index their library blocks so the agent knows which blocks are available during model building. Follow references/library-setup.md for options. Do not proceed until they respond.

If user confirms no libraries in Gate 1, save with confirmedNone: true and skip Gates 2 and 3.

Adding files to existing config

When .satk/reuse-libraries.json already exists with declared libraries: read the existing config, append the new library entries, save via library.LibraryConfig.save(), then regenerate the knowledge index with library.kg.Populate.run(projectRoot) so new blocks are indexed.

Guardrails

• Never write `.satk/` JSON files manually. Always follow the instructions and APIs in references/library-setup.md for each case.
• Do not use `find_system`, `load_system` to discover, validate, or enumerate library contents. All library operations must go through the specified APIs in references/library-setup.md.
• Each gate requires explicit user input before proceeding. Do not assume anything, wait for the response before moving to the next gate.

----

Copyright 2026 The MathWorks, Inc.

----