local-llm-integration

Instruction file imported from code-gamerr/BHARAT-BUILDS (.cursor/rules/local-llm-integration.mdc). Copyright stays with the author.

Local LLM Integration

Deploy, optimize, and serve open-weight local LLMs as a deterministic state machine using production serving engines (vLLM, Ollama, llama.cpp). Enforce strict I/O gatekeeping, GQA-aware pre-flight VRAM verification, process-scoped launches, OpenAI REST API bridging, constrained decoding, and TTFT SLA validation.

Required I/O Context Schemas

Before execution, inspect and populate the following context objects:

{
  "hardware_manifest": {
    "platform": "cuda | metal | cpu",
    "total_vram_mb": 24576,
    "free_vram_mb": 22000,
    "cuda_compute_capability": "8.9"
  },
  "model_spec": {
    "model_id": "Qwen/Qwen2.5-Coder-7B-Instruct-GGUF",
    "local_model_path": "/mnt/models/Qwen2.5-Coder-7B-Instruct-Q4_K_M.gguf",
    "param_count_b": 7.61,
    "quant_type": "gguf | awq | gptq | fp16",
    "quant_bytes_per_param": 0.55,
    "context_length": 8192,
    "layers": 28,
    "kv_heads": 8,
    "head_dim": 128
  },
  "deployment_config": {
    "engine": "vLLM | Ollama | llama.cpp",
    "port": 8000,
    "max_batch_size": 4,
    "precision_bytes": 2
  }
}

Context Field Reference & Dependency Matrix

1. hardware_manifest (Environment-Dependent)

• platform (Environment): Hardware acceleration target (cuda for NVIDIA GPUs, metal for Apple Silicon unified memory, cpu for host RAM fallback).
• total_vram_mb (Environment): Total installed GPU VRAM or Apple Silicon unified memory capacity in megabytes (e.g. 24576 for 24 GB).
• free_vram_mb (Environment): Currently unallocated VRAM headroom in megabytes prior to model initialization (discovered via CLI discovery commands).
• cuda_compute_capability (Environment): NVIDIA GPU architecture compute version (e.g. "8.9" for RTX 4090/Ada Lovelace, "8.0" for A100) determining flash attention and kernel capabilities.

2. model_spec (Model-Dependent)

• model_id (Model): Canonical HuggingFace repository identifier or local model name (e.g. "Qwen/Qwen2.5-Coder-7B-Instruct-GGUF").
• local_model_path (Model): Absolute file path to localized weight binary (e.g. "/mnt/models/Qwen2.5-Coder-7B-Instruct-Q4_K_M.gguf"), required for llama-server execution.
• param_count_b (Model): Total parameter count in billions (e.g. 7.61 for 7B models, 70.0 for 70B models), driving base weight VRAM calculations.
• quant_type (Model): Quantization format (gguf, awq, gptq, or fp16) controlling engine startup CLI flags (--quantization).
• quant_bytes_per_param (Model): Average byte weight per parameter (e.g. 0.55 for Q4_K_M, 0.65 for Q5_K_M, 2.0 for FP16), used in $VRAM_{weights_mb}$ math.
• context_length (Model/Environment): Target sequence window token length (e.g. 8192), scaling KV cache memory allocation.
• layers (Model): Total transformer layer count (e.g. 28 for Qwen 2.5 7B, 32 for Llama 3 8B).
• kv_heads (Model): Key-Value attention head count for Grouped-Query Attention (GQA) / Multi-Query Attention (MQA) (e.g. 8 for Llama 3 8B), preventing $4\times$ KV cache overestimation.
• head_dim (Model): Dimensionality per attention head (e.g. 128), used in GQA KV cache calculations.

3. deployment_config (Environment & Model Dependent)

• engine (Environment/Model): Target serving runtime (vLLM for high-concurrency CUDA servers, llama.cpp for edge/desktop/Metal).
• port (Environment): Local loopback TCP port for REST binding and process-scoped logging/PID management (e.g. 8000).
• max_batch_size (Environment/Model): Bounded sequence batch ceiling (e.g. 4), passed to --max-num-seqs / -np to constrain KV cache block pre-allocation.
• precision_bytes (Model): Precision size of KV cache elements in bytes (e.g. 2 for FP16 KV cache, 1 for Q8_0 FP8 KV cache).

State Machine Execution Protocol

Step 1: Hardware Discovery & GQA VRAM Proof

1. Execute exact CLI discovery command based on target architecture:

   • Linux CUDA: nvidia-smi --query-gpu=memory.total,memory.free --format=csv,noheader,nounits
   • macOS Metal: sysctl -n hw.memsize
   • Linux CPU/RAM Fallback: free -m

2. Compute deterministic VRAM consumption using Grouped-Query Attention (GQA):

   • $VRAM_{weights_mb} = \frac{param_count_b \times 10^9 \times quant_bytes_per_param}{1024^2}$
   • $VRAM_{kv_cache_mb} = \frac{2 \times layers \times kv_heads \times head_dim \times context_length \times max_batch_size \times precision_bytes}{1024^2}$
   • $VRAM_{total_mb} = VRAM_{weights_mb} + VRAM_{kv_cache_mb} + 2048$ (System safety buffer = 2048 MB)

3. Pre-flight Gate Assertion:

   • Evaluate $VRAM_{total_mb} \le free_vram_mb$.
   • If assertion fails: Abort execution immediately, emit JSON error {"status": "OOM_PREFLIGHT_FAIL", "required_mb": VRAM_total_mb, "available_mb": free_vram_mb}, and exit without spawning processes.

Step 2: Engine Selection & Process-Scoped Launch

1. Initialize execution environment variables dynamically:

   PORT=<port>
   PID_FILE="/tmp/indium_llm_${PORT}.pid"
   LOG_FILE="/tmp/indium_llm_${PORT}.log"

2. Construct quantization parameters dynamically:

   • If quant_type is "fp16", set QUANT_FLAG="".
   • Otherwise, set QUANT_FLAG="--quantization <quant_type>".

3. Launch background daemon bound to 127.0.0.1:<port>:

   • Path A: Enterprise CUDA Multi-User Server (vLLM):

     vllm serve <model_id> \
       --port <port> \
       --host 127.0.0.1 \
       ${QUANT_FLAG} \
       --gpu-memory-utilization 0.85 \
       --max-model-len <context_length> \
       --max-num-seqs <max_batch_size> \
       --guided-decoding-backend outlines > "${LOG_FILE}" 2>&1 &
     echo $! > "${PID_FILE}"

   • Path B: Edge / Desktop / Apple Silicon Metal (llama.cpp):

     llama-server \
       -m <local_model_path> \
       -c <context_length> \
       -np <max_batch_size> \
       --port <port> \
       --host 127.0.0.1 > "${LOG_FILE}" 2>&1 &
     echo $! > "${PID_FILE}"

Step 3: OpenAI API Bridging & Sampler Safeguards

1. Verify loopback REST endpoint listener binding at http://127.0.0.1:<port>/v1.
2. Inject default request template configurations into the client layer to prevent decoding loops:

   {
     "model": "<model_id>",
     "temperature": 0.2,
     "top_p": 0.9,
     "repetition_penalty": 1.1,
     "max_tokens": 2048,
     "response_format": {
       "type": "json_object"
     }
   }

Step 4: Health Check Polling & TTFT SLA Testing

1. HTTP Health Check Polling: Execute a bounded retry loop to allow weight loading into VRAM (timeout after 60s):

   PORT=<port>
   TIMEOUT=60
   ELAPSED=0
   until [ "$(curl -s -o /dev/null -w '%{http_code}' http://127.0.0.1:${PORT}/v1/models)" = "200" ]; do
     if [ $ELAPSED -ge $TIMEOUT ]; then
       echo "HEALTHCHECK_TIMEOUT"
       exit 1
     fi
     sleep 2
     ELAPSED=$((ELAPSED + 2))
   done

2. TTFT SLA Benchmark:

   PORT=<port>
   curl -s -w "\nTTFT: %{time_starttransfer}s\nTOTAL: %{time_total}s\nHTTP: %{http_code}\n" \
     -X POST http://127.0.0.1:${PORT}/v1/chat/completions \
     -H "Content-Type: application/json" \
     -d '{"model": "<model_id>", "messages": [{"role": "user", "content": "ping"}], "max_tokens": 10}'

   Assert time_starttransfer < 0.200 (Time-To-First-Token < 200ms SLA) and HTTP status equals 200.

Step 5: Process-Scoped Failure Recovery & Rollback Handler

If health checks time out, assertions fail, or CUDA OOM is detected in ${LOG_FILE}:

1. Capture diagnostic log snippet: tail -n 50 "${LOG_FILE}"
2. Terminate the scoped process hierarchy cleanly:

   PORT=<port>
   PID_FILE="/tmp/indium_llm_${PORT}.pid"
   if [ -f "${PID_FILE}" ]; then
     TARGET_PID=$(cat "${PID_FILE}")
     pkill -9 -P "${TARGET_PID}" 2>/dev/null
     kill -9 "${TARGET_PID}" 2>/dev/null
     rm -f "${PID_FILE}"
   fi

3. Return structured error JSON to the orchestrator.

Guardrails

• Never execute model loading without verifying the GQA VRAM math proof.
• Do not bind serving endpoints to external interfaces (0.0.0.0) without explicit authentication proxies.
• Process cleanup must be scoped strictly to the target instance PID file; global pkill calls are prohibited.
• YAML frontmatter must contain strictly name and description fields to pass distribution validation.

Completion Report

Report hardware_manifest metrics, model_spec parameters, computed $VRAM_{total_mb}$ vs $free_vram_mb$, instance PID, active loopback endpoint URL, HTTP health polling duration, measured TTFT SLA timing, and structured JSON output validation proof.