wecom-doc-fetcher

Use this skill when the user wants to save any page from the WeChat Work (企业微信) developer documentation site (developer.work.weixin.qq.com/document/path/*) as a clean Markdown file in their Obsidian vault.

Files in this skill

wecom-doc-fetcher/
├── SKILL.md          # this file
└── wx_doc_fetch.py   # the fetch & convert script

Setup (one-time)

Run these once before using the skill:

pip install requests playwright
playwright install chromium

playwright install chromium downloads a ~150 MB headless Chromium binary. This is required for automatic doc_id detection.

Python 3.8+ is required.

Usage

Place wx_doc_fetch.py anywhere convenient (e.g. your vault's scripts folder), then run:

# Basic: auto-detect doc_id, print to stdout
python wx_doc_fetch.py <URL>

# Save to file
python wx_doc_fetch.py <URL> output.md

# Skip Playwright, supply doc_id manually
python wx_doc_fetch.py <URL> output.md --doc-id <integer>

# Override cookies at runtime
python wx_doc_fetch.py <URL> output.md --cookies "wwapidoc.sid=xxx; ..."

Example

python wx_doc_fetch.py https://developer.work.weixin.qq.com/document/path/94677 发送消息.md
# [info] path_id=94677  doc_id=31152
# [done] 已写入：发送消息.md

How It Works

The WeChat Work docs site is a Vue SPA — the visible content is not in the initial HTML. It is loaded at runtime via a private POST API:

POST https://developer.work.weixin.qq.com/docFetch/fetchCnt?lang=zh_CN&ajax=1&f=json
Body: doc_id=<integer>   (application/x-www-form-urlencoded)

The response includes data.content_md — the page content as a Markdown string. The script fetches this field, cleans it, and writes the result.

Why not WebFetch / defuddle?

The page renders client-side. WebFetch and defuddle only see the pre-JS HTML skeleton — no content. Scraping innerText via browser tools works but produces a very large accessibility tree with poor formatting. The content_md API field is the cleanest, most token-efficient source.

URL path ID ≠ doc_id

The number in the browser URL (e.g. 94677) is a routing slug — not the doc_id the API needs. The actual doc_id (e.g. 31152) is determined at runtime by loading the page with Playwright and intercepting the fetchCnt XHR request.

Manual doc_id Fallback

If Playwright is unavailable or times out:

1. Open the target URL in Chrome
2. DevTools → Network tab → filter by fetchCnt
3. Click the request → Payload tab
4. Read the doc_id value
5. Pass it with --doc-id:

python wx_doc_fetch.py https://developer.work.weixin.qq.com/document/path/94677 发送消息.md --doc-id 31152

Cookie Configuration

The fetchCnt API requires an authenticated session. Playwright's headless browser obtains session cookies automatically when loading the page — no manual cookie setup needed for normal use.

If you see errCode: -30001 in the output, the session is rejected. Fix:

1. Open the site in Chrome while logged in
2. DevTools → Network → any fetchCnt request → Copy as cURL
3. Find the -b '...' cookie string in the copied command
4. Either paste it into COOKIES_RAW at the top of wx_doc_fetch.py, or pass it via --cookies "..."

Key cookies and their lifetimes:

| Cookie | Purpose | Lifetime |

|--------|---------|---------|

| wwapidoc.sid | Session identifier | ~24 hours |

| wwapidoc.token_wt | JWT auth token | ~30 minutes |

API Reference

| Item | Detail |

|------|--------|

| Endpoint | POST /docFetch/fetchCnt?lang=zh_CN&ajax=1&f=json&random= |

| Body | doc_id= (form-urlencoded) |

| Auth | Session cookies |

| Key response field | data.content_md |

| Other response fields | data.content_html, data.content_html_v2, data.content_txt, data.title, data.time |

content_md Cleaning Rules

The content_md field is mostly valid CommonMark but has site-specific issues. The clean_md() function in wx_doc_fetch.py handles all of them:

| # | Problem | Raw example | After cleaning |

|---|---------|-------------|----------------|

| 1 | [TOC] marker at top | [TOC]\n# 概述 | # 概述 |

| 2 | Heading missing space after # | ##接口定义 | ## 接口定义 |

| 3 | Internal numeric anchor links | 接收事件 | 接收事件 |

| 3 | Anchors with sub-path | 开启API | 开启API |

| 4 | HTML line breaks inside table cells | 说明
补充 | 说明 补充 |

| 5 | bold tags | 注意 | 注意 |

# CORRECT — matches on start of line, avoids breaking table rows apart
re.sub(r"^([^|\n][^\n]*)\n(\|)", r"\1\n\n\2", content, flags=re.MULTILINE)

# WRONG — table rows end with "| " (trailing space), so last char is space,
#          causing blank lines to be inserted between every table row
re.sub(r"([^\n])\n(\|)", r"\1\n\n\2", content)