External Model Delegation Pattern

A UserPromptSubmit hook classifies every user prompt into one of six cost/performance tiers. The hook injects additionalContext instructing Claude to run a specific delegation script and return the output.

Tier routing table

Tier	Delegation command	Cost
QWEN	`qwen3 "prompt"`	$0 (local Ollama)
DEEPSEEK_FLASH	`deepseek --flash "prompt"`	$0.14 / $0.28 per M tokens
DEEPSEEK_PRO	`deepseek --pro "prompt"`	$0.44 / $0.87 per M tokens
KIMI	`kimi --quiet -p "prompt"`	$0.60 / $2.50 per M tokens
CODEX	`codex exec`	varies
CLAUDE	handle natively	$3-5 / $15-25 per M tokens

Delegation script pattern

Each script is a self-contained executable in ~/bin/ that accepts a prompt and writes the response to stdout:

~/bin/
├── qwen3      # Shell: curl to local Ollama API
├── kimi       # Shell: execs Kimi CLI binary
├── deepseek   # Python: httpx to DeepSeek Anthropic-compat API
└── route-task # Shell + qwen3: classifies prompt into tier

Script contract

Accept prompt as first argument: qwen3 "what is 2+2"
Support --flash / --pro model flags (deepseek)
Support --quiet mode flag (kimi)
Write response to stdout, errors to stderr
Exit 0 on success, non-zero on error

Writing a new delegation script

#!/bin/bash
# Minimal delegator template
PROMPT="$1"
API_KEY="${EXTERNAL_API_KEY:-}"
# Call external API, write result to stdout
curl -s https://api.example.com/chat \
  -H "Authorization: Bearer $API_KEY" \
  -d "$(jq -n --arg p "$PROMPT" '{prompt: $p}')" \
  | jq -r '.response'

Routing hook flow

User types prompt
    ↓
UserPromptSubmit hook fires
    ↓
qwen3 classifies into tier (QWEN|DEEPSEEK_FLASH|DEEPSEEK_PRO|KIMI|CODEX|CLAUDE)
    ↓
Hook injects additionalContext: "Run: <delegation-command>"
    ↓
Claude reads context, spawns delegation script, returns output
    ↓
User sees response from the delegated model

Classification tiers

Tier	Task types
QWEN	grep, find, regex, shell, syntax lookups, log reading, short summaries
DEEPSEEK_FLASH	Simple code, boilerplate, CRUD, test writing, small fixes, config
DEEPSEEK_PRO	Multi-file features, refactors, debugging, medium coding, docs
KIMI	Single-file review, medium reasoning, commit messages, diff summaries
CODEX	Bulk generation, mechanical changes across many files
CLAUDE	Architecture, security, complex debugging, system design, quality-critical

Environment

# Required env vars (set in ~/.zshrc)
export DEEPSEEK_API_KEY="sk-..."      # For deepseek delegator
export OPENAI_API_KEY="sk-..."         # For codex CLI
# Ollama must be running locally for qwen3 classification + delegation

external-model-delegation