Component Registry

Synth's component registry is a library of part definitions. Each part is a .synth.toml file that describes the component's kind, pins, KiCad symbol and footprint, and manufacturer part numbers. Parts are referenced in your .synth files by their part ID.

Finding Parts

Search locally

synth registry list

Lists every part ID in the registry with its tier (shipped or user-added):

tier1 (shipped): ams1117_3v3
tier1 (shipped): bme680_env
tier1 (shipped): c_generic_0402
tier1 (shipped): c_generic_0603
tier1 (shipped): r_generic_0603
tier1 (shipped): stm32f103c8
tier1 (shipped): usb_c_receptacle
...

Use synth registry doctor to check for any registry issues, and synth registry path to see where your registry directories are.

Search live (LCSC stock + pricing)

# Using the MCP server (from an AI assistant)
synth_search_registry_web query="AMS1117 3.3V LDO"

This searches LCSC/EasyEDA live and returns stock quantity, price, and the C-number you can use to import the part. Falls back to the local registry when offline.

Using Parts in Your Design

Reference a part ID in a component declaration:

component U1: regulator "ams1117_3v3"
component C1: capacitor "c_generic_0603"
component J1: connector "usb_c_receptacle"

The part ID string must exactly match an entry from synth registry list. Pin names for connect statements come from the part definition — see Inspecting a Part below.

Inspecting a Part

To see a part's pin names before writing connect statements, inspect it:

synth registry list   # find the part ID first

Or use the MCP server from an AI assistant:

synth_search_registry query="ams1117"

This returns the part's pins, so you know to write U1.vin, U1.vout, U1.gnd rather than guessing.

Importing Parts

Synth can import parts from several sources into your personal Tier-2 registry. Imported parts are tagged as unverified (W-SYNTH-PART-UNVERIFIED) until a human reviews the pin table.

From LCSC / JLCPCB

Import by the C-number shown on the LCSC or JLCPCB parts page:

synth part import-lcsc C6186

JLCPCB and LCSC share the same part numbering — C6186 (the LCSC code) is the same part as the JLCPCB entry showing C6186 as the "JLCPCB Part #".

From KiCad Symbol Libraries

Import from KiCad's bundled stock symbols (must have KiCad installed):

synth part import-kicad Regulator_Linear:AMS1117-3.3
synth part import-kicad MCU_Microchip_SAMD:ATSAMD21E18A

From SnapEDA / UltraLibrarian

Download a "Export to KiCad" zip through your browser, then import the file:

synth part import-zip ~/Downloads/my-ic.zip

[!NOTE] Synth never contacts SnapEDA or UltraLibrarian directly. Their terms of service prohibit automated access. You download the zip manually through their website; Synth only reads the local file.

Author from Scratch

Create a blank stub and fill it in from the datasheet:

synth part stub my-custom-ic --pins 8

This writes a .synth.toml skeleton into your Tier-2 registry with numbered pins. Edit the file to add real pin names and electrical types.

Registry Tiers

Synth uses a two-tier registry:

Tier-2 parts shadow Tier-1 parts with the same ID. Run synth registry doctor to see any shadowing warnings.