Stock-Based Component Selection

Find a shortlist of parts that can be bought now. This skill covers supplier stock and purchase constraints, not the electrical design. Search by the requirement, not by a preferred manufacturer, part number or category.

Scope and boundaries

• Sources: DigiKey, Mouser, LCSC and the JLCPCB Parts Library. Search the suppliers the user names; with none named, use all that apply. Their catalogs differ.
• Keep supplier stock apart from the user's own inventory. Use the user's stock records only when they supply them.
• Stock, price and lead time change. Take them from current supplier listings, authorized APIs or exports the user gives, and record the source and date. Without live access, the value is NOT_VERIFIED.
• Source genuine, traceable parts. Check the exact manufacturer MPN with suffix, and keep it apart from the supplier SKU (DigiKey or Mouser number, LCSC code, JLCPCB part number).
• Available to order is not on hand, listed is not assembly-ready, and supplier stock is not a reservation.
• Ordering, reserving, uploading a BOM, signing in and changing a KiCad project all need explicit authorization. Inspection is read-only.
• Engineering fit and trade-offs, and datasheet, package, footprint and pinout checks, are separate work (component-select and component-check, if installed). Passing the stock filters does not mean the part is electrically approved.

Workflow

1. Scope the purchase. The function or existing MPN, required electrical and package constraints, quantity, ship-to region, budget, needed delivery date, and whether JLCPCB assembly is needed. State assumptions for missing items, and give total cost only when quantity and region are known.
2. Search the catalogs. Search the exact MPN first for replacements or BOM sourcing; use parametric search to find alternatives. Record the exact listing URL or source record for each candidate.
3. Normalize identifiers. Manufacturer, full orderable MPN, supplier, supplier SKU, package, lifecycle when shown, and any listing ambiguity. Merge two listings only when the MPN matches, not because the descriptions look alike.
4. Apply hard filters. Reject candidates that fail a required electrical, environmental, package, assembly, traceability or lead-time constraint. A missing critical value is NOT_VERIFIED, not PASS.
5. Check purchase conditions. Sellable quantity versus non-stock, lead time or backorder; order increments, MOQ, packaging (cut tape, reel, tray), price breaks at the requested quantity, currency, and shipping-region limits. Tax and shipping stay estimates.
6. Check JLCPCB on its own. Look up the JLCPCB assembly parts library directly: part code, assembly eligibility, Basic or Extended when shown, stock usable for the PCBA order, and pre-order or consignment limits. LCSC stock does not prove JLCPCB assembly stock, and a JLCPCB library part may not ship on its own.
7. Shortlist and stop. Give two or three qualified purchase options that differ in a real way, or say that none pass. Prefer parts that can actually be bought, but never trade a required engineering constraint for stock.

Output contract

• Search context: requirements, quantity, region, suppliers searched, and date and time checked.
• Candidate table: exact MPN, supplier SKU, source, stock, price at the relevant quantity, MOQ or increment, package, and assembly eligibility where it applies. Missing fields are NOT_VERIFIED.
• Recommendation: RECOMMENDED, ALTERNATIVE, REJECTED or NOT_VERIFIED, with the reason and any main sourcing risk.
• Next step: the critical electrical or package check, or a stock recheck right before purchase or PCBA submission.

Being in stock does not make a part pin-compatible, drop-in or approved. With no live supplier data, give a clearly labeled sourcing plan or provisional shortlist.

Example

Context: <MPN A>, qty 10, ship to <region>, DigiKey + LCSC + JLCPCB, checked YYYY-MM-DD
<MPN A> | DigiKey <SKU> | stock 1,200 | $0.42 at qty 10 | page fetch    | RECOMMENDED
<MPN A> | LCSC <code>   | stock NOT_VERIFIED (page timed out)            | NOT_VERIFIED
<MPN A> | JLCPCB <code> | Extended, stock 0 for PCBA                     | REJECTED for assembly
Next:    recheck LCSC stock before ordering; JLCPCB assembly needs another part or consignment.