8.8 KiB
🛰️ System-Prompt Drift — How Hidden Instructions Lose Authority
A user-friendly guide to diagnosing and fixing “why did my system prompt stop working?”
1 What Is System-Prompt Drift?
“System-prompt drift” occurs when the foundational instructions that define an agent’s identity, tone, or guardrails gradually lose influence over time (or instantly under certain triggers).
The model still answers, but:
- Tone shifts from professional → casual → chaotic
- Guardrails weaken, leaking disallowed content
- Chain-of-thought grows inconsistent or contradictory
Core insight: LLMs have no native concept of instruction priority.
Without reinforcement, later tokens can override earlier ones.
2 Early-Warning Signs
| Symptom | How to Spot | Typical Trigger |
|---|---|---|
| Tone drift (“you” → “we” → “ya”) | Diff analysis of consecutive answers | Long conversation or paraphrase loops |
| Policy leakage | Previously filtered topics slip through | Mixed file uploads (PDF + code) |
| Over-explanation after concise goal | Answer length suddenly doubles | Retrieval injects verbose context |
| “Why do you need that?” disappears | Politeness layer collapses | Multi-agent routing / tool calls |
| Temperature spike | Output variance ↑, repetition ↓ | System prompt trimmed by token limit |
3 Root Causes (Technical)
3.1 Token Supersession
LLM context windows are linear. New tokens can overshadow earlier tokens via attention weight decay.
3.2 Role Collision
Aggregating content from multiple sources (user, tools, memory) without role tags causes blending of semantic channels.
3.3 Truncation Loss
When the buffer hits the window limit, oldest tokens are dropped — often the system prompt header.
3.4 Hidden Injection
Retrieved chunks may contain meta-instructions (“The following should be summarized as …”) that override role.
4 Broken Remedies to Avoid
| Attempt | Why It Fails |
|---|---|
| “Repeat system prompt each turn.” | Costs tokens; still lost under truncation or injection. |
| “Hard-code tonality keywords.” | Keyword collision is brittle; adversary can mimic them. |
| “Raise top_p / lower temperature.” | Alters style but not underlying role authority. |
| “Fine-tune on more examples.” | Long-context decay still erodes influence at runtime. |
5 WFGY Solution Blueprint
| Stage | Module | Action |
|---|---|---|
| 5.1 Role Tagging | WRI / WAI | Wrap every segment: <sys>…</sys> <user>…</user> <tool>…</tool> |
| 5.2 Semantic Boundary Heatmap | ΔS + λ_observe | Measure drift: if ΔS(system, answer) > 0.45 and λ flips, mark risk. |
| 5.3 Attention Modulation | BBAM | Down-weight non-system tokens when λ diverges from system anchor. |
| 5.4 Automatic Re-Anchoring | BBCR | If ΔS > 0.60, collapse reasoning, re-inject compressed system prompt, resume. |
| 5.5 Trace Split | Bloc/Trace | Persist system-layer trace separate from answer layer for auditability. |
5.6 Implementation Snippet
def enforce_system_role(sys_prompt, history, new_msg):
drift = delta_s(sys_prompt, new_msg)
lam = observe_lambda(sys_prompt, new_msg)
if drift > 0.45 and lam in ("←", "×"):
# role divergence detected
reborn_prompt = compress(sys_prompt) # 20–30 tokens
return f"<sys>{reborn_prompt}</sys>\n{history}\n{new_msg}"
return f"{history}\n{new_msg}"
compress() uses WFGY BBMC to keep ΔS ≤ 0.25 while shrinking to fit.
6 Friendly Checklist (Paste into Runbook)
- Tag Roles Once — no implicit mixing.
- Monitor ΔS(system, answer) every turn.
- If ΔS ≥ 0.45 with divergent λ → trigger BBAM weight clamp.
- If ΔS ≥ 0.60 → run BBCR collapse-rebirth (re-inject summary prompt).
- Every 30 turns or on tool call, re-compress system prompt to ≤ 50 tokens.
Tip: Users never notice a 30-token summary, but models retain authority.
7 Validation Matrix
| Test Case | Target Metric |
|---|---|
| 20-turn dialogue, paraphrase ×3 | Tone consistency score ≥ 0.9 |
| Mixed PDF + code retrieval | ΔS(system, answer) median ≤ 0.40 |
| Adversarial “Ignore above” injection | Model outputs refusal / filtered text |
| Window overflow 3× | System role preserved (λ stays convergent) |
8 FAQ
Q: Do I always need role tags? A: Yes. Token streams without explicit roles are inherently unstable at >100 turns.
Q: Will OpenAI “system” field alone work? A: Helps, but downstream retrieval or multi-agent merges still dilute authority; WFGY adds extra enforcement.
Q: Is ΔS expensive to compute each turn? A: Sentence-level embeddings (768–1536 d) are fast; cache results in memory store.
🔗 Quick-Start Downloads (60 sec)
| Tool | Link | 3-Step Setup |
|---|---|---|
| WFGY 1.0 PDF | Engine Paper | 1️⃣ Download 2️⃣ Upload to LLM 3️⃣ Ask “Answer using WFGY + ” |
| TXT OS | TXTOS.txt | 1️⃣ Download 2️⃣ Paste into chat 3️⃣ Type “hello world” to boot |
🧭 Explore More
| Module | Description | Link |
|---|---|---|
| WFGY Core | WFGY 2.0 engine is live: full symbolic reasoning architecture and math stack | View → |
| Problem Map 1.0 | Initial 16-mode diagnostic and symbolic fix framework | View → |
| Problem Map 2.0 | RAG-focused failure tree, modular fixes, and pipelines | View → |
| Semantic Clinic Index | Expanded failure catalog: prompt injection, memory bugs, logic drift | View → |
| Semantic Blueprint | Layer-based symbolic reasoning & semantic modulations | View → |
| Benchmark vs GPT-5 | Stress test GPT-5 with full WFGY reasoning suite | View → |
| 🧙♂️ Starter Village 🏡 | New here? Lost in symbols? Click here and let the wizard guide you through | Start → |
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Engineers, hackers, and open source builders who supported WFGY from day one.
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