Elective

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name: elective description: "PKU Course Selection (选课网) CLI tool built in Rust. Use this skill when working on the elective crate, debugging elective commands, adding features, or when the user mentions 选课, elective, course selection, auto-enroll, CAPTCHA solving, dual-degree, or elective.pku.edu.cn. Also use when dealing with CAPTCHA recognition backends (utool/ttshitu/yunma), automated course enrollment loops, or elective SSO callback. NOT for general course schedule / 课表 / 这学期上什么课 questions — use the treehole skill (treehole course) instead, which gives a unified weekly grid with 主修+辅修+双学位. The elective show command only sees one program at a time and easily misses courses from the other program for dual-degree students." version: 2.0.0

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Elective - 北大选课网 CLI

A CLI client for PKU's course selection system with auto-enrollment automation.

Architecture

Crate location: crates/elective/

Auth flow: IAAA SSO (app_id="elective") → elective SSO endpoint callback

API: HTML scraping + CAPTCHA handling (base64 image recognition)

Automation: Polling loop for auto-enrollment with configurable interval

Key Source Files

src/main.rs — Clap CLI with subcommands

src/commands.rs — Command implementations including auto-enroll loop

src/api.rs — HTML scraping, CAPTCHA image extraction

src/display.rs — Terminal output formatting

src/client.rs — reqwest client builders

CLI Commands

| Command | Alias | Function | |---------|-------|----------| | login | | IAAA login (supports --dual for dual-degree students) | | logout / status | | Session management | | show | | View current course selections | | list | ls | Browse available courses for add/drop | | set | | Add a course to auto-enroll target list | | unset | | Remove from auto-enroll targets | | config-captcha | | Configure CAPTCHA solver backend | | launch | | Start auto-enrollment polling loop | | otp | | TOTP 2FA management |

CAPTCHA Backends

The config-captcha command supports multiple recognition backends:

manual — Display CAPTCHA image, user inputs answer

utool — UTool OCR service

ttshitu — TTShiTu recognition API

yunma — Yunma recognition API

Auto-Login for AI Agents

# Check session status
info-auth check
Auto-login (reads credentials from OS keyring, no password needed)
elective login -p                  # single degree
elective login -p --dual major     # dual degree - major
elective login -p --dual minor     # dual degree - minor

Note: Dual-degree students MUST specify --dual major or --dual minor, otherwise login will fail with an error.

Development Notes

Auto-enrollment loop: configurable check interval (default 15s), polls for open slots

Dual-degree students use --dual flag at login for separate session

CAPTCHA images are base64-encoded, decoded and sent to recognition backend

All user-facing strings in Chinese

Error handling: anyhow::Result with .context("中文描述")

Session persisted to ~/.config/info/elective/

Credentials resolved via info_common::credential (keyring → env → interactive)