feat: added support for z.ai coding plan via API as an alternative to anthropic

[mohitsinghdz]

Summary

Added support for Z.AI's GLM coding plan as an alternative LLM provider, allowing Shannon to run penetration tests using Z.AI's Anthropic-compatible API endpoint instead of direct Anthropic API or the router-based multi-model setup.

Changes

1. New GLM=true CLI flag (shannon)

• Added GLM=true option to the shannon CLI script
• When enabled, configures the Anthropic SDK to route through Z.AI's Anthropic-compatible endpoint (https://api.z.ai/api/anthropic)
• Sets ANTHROPIC_AUTH_TOKEN from ZAI_API_KEY for authentication
• Handles mutual exclusivity with ROUTER=true (GLM takes priority with a warning)
• Added validation that ZAI_API_KEY is set when GLM=true
• Added fallback placeholder ANTHROPIC_API_KEY="glm-mode" to satisfy SDK initialization

2. Router config update (configs/router-config.json)

• Added zai provider configuration pointing to https://api.z.ai/api/paas/v4/chat/completions
• Configured with max_completion_tokens: 16384 transformer
• Uses $ZAI_API_KEY environment variable for authentication

3. Docker environment passthrough (docker-compose.yml)

• Added ZAI_API_KEY to both shannon-worker and claude-code-router services

4. GLM detection utility (src/ai/router-utils.ts)

• Added isGlmDirectMode() function to detect when Z.AI direct mode is active (checks if ANTHROPIC_BASE_URL contains api.z.ai)
• Updated isRouterMode() to exclude GLM direct mode, preventing it from being incorrectly treated as router mode

5. Environment example (.env.example)

• Added OPTION 3: Z.AI GLM Mode section with ZAI_API_KEY placeholder
• Documented the GLM=true flag usage

Usage

# Set in .env
ZAI_API_KEY=your-zai-api-key

# Run with GLM mode
./shannon start URL=https://example.com REPO=/path/to/repo GLM=true

Files Changed

File	Changes
shannon	+22 lines — CLI flag parsing, validation, endpoint configuration
src/ai/router-utils.ts	+9/-2 — GLM detection + router mode fix
configs/router-config.json	+9 — Z.AI provider config
docker-compose.yml	+2 — ZAI_API_KEY env passthrough
.env.example	+7 — Documentation and example

Test Plan

• Run ./shannon start URL=<url> REPO=<path> GLM=true with a valid ZAI_API_KEY
• Verify error when GLM=true is set without ZAI_API_KEY
• Verify GLM=true takes priority over ROUTER=true with a warning
• Confirm isGlmDirectMode() returns true when Z.AI endpoint is configured
• Confirm isRouterMode() returns false in GLM direct mode