altium-schematic-reader

name	altium-schematic-reader
description	Read and reason about Altium Designer projects and schematics using structured data from .PrjPcb and .SchDoc files. Use when the user asks an AI to understand, explain, review, debug, summarize, inspect, or query an Altium circuit design, including components, nets, pin-level connectivity, BOMs, variants, sheet hierarchy, power rails, or questions like what is connected to a pin.

Altium Schematic Reader

Use this skill to answer questions about Altium schematic designs with grounded circuit facts instead of guesses from filenames or screenshots.

The bundled script reads Altium files through altium-monkey and returns compact JSON slices for AI reasoning.

Prerequisites

altium-monkey must be importable in the Python environment.

Preferred installation:

pip install altium-monkey

When working inside an altium_monkey source checkout, set PYTHONPATH to its src/py directory before running the script.

$env:PYTHONPATH="path\to\altium_monkey\src\py"

Locate The Design

If the user does not name a project, find candidate Altium projects:

Get-ChildItem -Recurse -Filter *.PrjPcb

If there is more than one plausible project, ask which one to inspect. For a single .SchDoc, use the sheet command.

Command Pattern

Run from any working directory:

python <skill_dir>\scripts\read_schematic.py <command> [args]

All commands print JSON to stdout. Errors print JSON to stderr.

Workflow

Always start with summary for a project you have not inspected in this session.

python <skill_dir>\scripts\read_schematic.py summary path\to\Project.PrjPcb

Then choose targeted follow-up queries:

• Use components --brief to understand what is on a sheet.
• Use nets to list named nets or search rail/signal names.
• Use nets --name NET_NAME to inspect every terminal on a net.
• Use connections --designator U1 to inspect all connected pins of a component.
• Use connections --designator U1 --pin 5 for one pin.
• Use bom for bill of materials and variant questions.
• Use sheet only when no .PrjPcb is available.
• Use raw design or raw netlist only as a last resort because the output can be large.

For MCU, processor, connector, and header tables, do not rely only on netlist connections. Netlists omit unconnected pins. Inspect the component symbol pins (component.pins through altium-monkey, or altium-circuit-investigator port_inventory.py) and merge those pins with netlist endpoints so every pin is listed, including NC/未连接 pins.

Commands

Project summary:

python <skill_dir>\scripts\read_schematic.py summary path\to\Project.PrjPcb

Components:

python <skill_dir>\scripts\read_schematic.py components path\to\Project.PrjPcb --brief
python <skill_dir>\scripts\read_schematic.py components path\to\Project.PrjPcb --sheet Power.SchDoc --brief
python <skill_dir>\scripts\read_schematic.py components path\to\Project.PrjPcb --designator U7

Nets:

python <skill_dir>\scripts\read_schematic.py nets path\to\Project.PrjPcb
python <skill_dir>\scripts\read_schematic.py nets path\to\Project.PrjPcb --contains P3V3
python <skill_dir>\scripts\read_schematic.py nets path\to\Project.PrjPcb --name GND

Pin-level connectivity:

python <skill_dir>\scripts\read_schematic.py connections path\to\Project.PrjPcb --designator U7
python <skill_dir>\scripts\read_schematic.py connections path\to\Project.PrjPcb --designator U7 --pin C9

BOM:

python <skill_dir>\scripts\read_schematic.py bom path\to\Project.PrjPcb
python <skill_dir>\scripts\read_schematic.py bom path\to\Project.PrjPcb --variant PCBA_Build

Single sheet:

python <skill_dir>\scripts\read_schematic.py sheet path\to\Sheet.SchDoc

Raw escape hatch:

python <skill_dir>\scripts\read_schematic.py raw path\to\Project.PrjPcb design
python <skill_dir>\scripts\read_schematic.py raw path\to\Project.PrjPcb netlist

Reasoning Rules

• Cite designators, pin numbers, net names, and sheet filenames in answers.
• Prefer project-level commands over single-sheet inspection because designators and hierarchy are resolved at project level.
• Do not infer connectivity from symbol graphics or component names when a netlist query is available.
• Distinguish "not present in the netlist" from "not present on the symbol": an unconnected symbol pin must still be reported as NC when pin coverage matters.
• For any unclear signal name such as CTRL, OUT, IN, FB, AD, QD, or AUX, inspect local schematic labels or use altium-circuit-investigator before naming the function.
• For "what does this circuit do", inspect summary, then sheet-level component briefs, then connections for the main ICs.
• For power questions, inspect summary.power_and_ground_nets, rail-like net names, and POWER pins on target ICs.
• For review questions, look for evidence first, then separate confirmed issues from hypotheses.

Known Boundaries

• Complex hierarchical channels and .Annotation-driven mappings may need manual validation.
• Variant support depends on altium-monkey and may be limited for unusual variant setups.
• Parse failures should be reported with the failing file path and exact JSON error.
• altium-monkey is AGPL-3.0-or-later; review license obligations before embedding it in a distributed or network service.

References

Read references/software_design.md when designing a backend, API, cache, UI, or AI workflow around this skill.