jlcpcb

Python client and CLI for the JLCPCB SMT parts catalogue. Search, filter, fetch part detail, download datasheets and product images, and pull EasyEDA symbols / footprints — all via the same internal JSON endpoints the JLCPCB SPA uses.

See docs/RESEARCH.md for the reverse-engineered API specification, and src/jlcpcb/skills/SKILL.md for the agent-side workflow guide.

Library quick start

from jlcpcb import JLCPCB

with JLCPCB() as c:
    result = c.search(keyword="STM32F103C8T6", page_size=10)
    detail = c.get_by_code("C8734")
    pdf = c.download_datasheet("C8734")
    brands_by_letter = c.brands()

CLI quick start

The CLI follows the 10 Principles for Agent-Native CLIs (Trevin Chow, May 2026). Highlights:

• Non-interactive by default. No prompts, no hangs.
• JSON output when stdout is piped (the agent case); plain table when a TTY is attached. --json and --table force either.
• Stable exit-code taxonomy: 0/2/3/4/5/6/7/8/9 — visible in jlcpcb agent-context | jq .exit_codes.
• Enumerating errors: every enum rejection names the valid set in the message and suggests a working invocation.
• --limit default 25 (server cap 72), with truncated / hint in the JSON envelope.
• Cross-CLI vocabulary: list / get / --force / --json / --limit — banned synonyms (info, ls, --format=json, --skip-confirmations) are statically enforced (tests/cli/test_vocabulary.py).
• Three-layer introspection: --help, jlcpcb agent-context, jlcpcb skill-path → SKILL.md.
• Persistent profiles (profile save/list/get/delete).
• Job ledger (job list/get/prune) ready for future long-running ops.
• --deliver=stdout|file:<path>|webhook:<url> for download artefacts, atomic file write, structured refusal on unknown schemes.
• feedback "..." records to ~/.jlcpcb/feedback.jsonl; POSTs to $JLCPCB_FEEDBACK_ENDPOINT if set.

# search
jlcpcb part list -q STM32F103C8T6 --limit 5 --in-stock

# single detail
jlcpcb part get C8734

# download datasheet to file
jlcpcb part datasheet download C8734                     # ./C8734.pdf
jlcpcb part datasheet download C8734 --deliver=stdout > out.pdf
jlcpcb part datasheet download C8734 --deliver=webhook:https://example.com/hook

# categories / brands / hot / fx
jlcpcb category list --limit 10
jlcpcb category get 2973
jlcpcb brand list --letter A --limit 5
jlcpcb hot list
jlcpcb fx list

# profiles
jlcpcb profile save mcus --library expand --in-stock --limit 50
jlcpcb --profile=mcus part list -q STM32

# agent introspection
jlcpcb agent-context | jq '.commands.part.subcommands.list.flags'
cat $(jlcpcb skill-path | jq -r .path)/SKILL.md

Install

pip install -e .[dev]

The jlcpcb console_scripts entry is wired automatically by pip install. Without install you can run the CLI in-tree via:

PYTHONPATH=src python -m jlcpcb.cli <args>

Test

pytest                       # 188 tests, ~40 s (live tests skipped)
JLCPCB_LIVE=1 pytest         # 224 tests, ~110 s (includes 36 live tests)

The test suite is Detroit-school: unit and component tests exercise real collaborators (Pydantic models, filter builders, the SSR parser, the Click app) and only stub the HTTP transport via respx with fixtures captured from the live API. Integration tests hit jlcpcb.com directly.

tests/cli/test_vocabulary.py is the policy enforcer the article calls out: banned verbs and flag synonyms fail the test the moment they enter the command tree, so the CLI surface can't silently drift away from the convention.

To refresh the captured HTTP fixtures from the live API:

PYTHONPATH=src python scripts/capture_fixtures.py
PYTHONPATH=src python scripts/trim_manufacturers.py