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942f852092
In this commit, we record the verdict of the drift experiment, and it answers both halves of the question cleanly while pointing them in opposite directions. Time-awareness did re-evolve: the code_drift1 winner is the first evolved router with time-based logic, stamping every liquidity belief, decaying its confidence on a 35 minute half-life, expiring hard bounds outright after 20 minutes, and interpolating between learned beliefs and the bimodal prior by that confidence -- evidence softening with age, structurally unlike lnd's penalty fading. Selection pressure produced exactly the mechanism the experiment was designed to test for. And yet it does not win. On the drift corpus itself the time-aware winner scores 0.417 against the time-less champions' 0.455 and 0.457 -- and most damning, against gen2's 0.456, a router with the same budget and seed style that never saw drift during evolution. lnd's rationale for decay is validated; its necessity is not. At realistic churn, hard evidence bounds degrade gracefully enough that a stale bound costs one retry, which is cheaper than the information the decay machinery throws away. Champions of record remain hb1 and mx_c3, now validated on a fourth held-out tier. We archive the winner's source beside the writeup and update the notebook and CLAUDE.md accordingly. |
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|---|---|---|
| .. | ||
| champions | ||
| command-center | ||
| lab | ||
| .gitignore | ||
| codex_lm.py | ||
| evaluate.py | ||
| evaluate_code.py | ||
| export_run.py | ||
| gen_scenarios.py | ||
| preflight.py | ||
| README.md | ||
| refresh_dashboard.sh | ||
| run_gepa.py | ||
| run_gepa_code.py | ||
| run_gepa_omni.py | ||
Routing Optimization Harness
This directory holds the GEPA-based optimization harness for lnd's pathfinding. The core idea: lnd's real routing code (or a candidate replacement algorithm) runs against an in-process simulated Lightning Network with hidden liquidity, an evaluator scores the outcome, and a reflective LLM optimizer (GEPA) proposes improved candidates from the failure feedback.
Components
| Piece | Where | What |
|---|---|---|
| Simulator | routing/sim_*.go |
In-memory LN with hidden balances; real pathfinding + mission control run unmodified against it |
| CLI | cmd/routesim |
params JSON + scenario file in, attempt traces + aggregate JSON out |
| Candidate slot | cmd/routesim/candidate_impl.go |
A complete routing algorithm behind --router=candidate; swapped per candidate via go build -overlay |
| Corpus | gen_scenarios.py |
train/val/test scenario files: topology + liquidity seed + payment batch |
| Evaluators | evaluate.py, evaluate_code.py |
score = success rate − small saturating penalties for attempts and fee ppm |
| Runners | run_gepa.py, run_gepa_code.py |
parameter mode and code mode optimization |
| Reflection LM | codex_lm.py |
GEPA LM protocol via codex exec headless (default gpt-5.6-sol) |
| Lab notebook | lab/ |
running log of experiments, results, ideas |
Quick start
# Build the simulator binary.
go build -o /tmp/routesim ./cmd/routesim
# Generate a scenario corpus.
python3 simulation/gen_scenarios.py --out /tmp/corpus
# Score the lnd defaults on one example.
cd simulation && ROUTESIM_BIN=/tmp/routesim python3 evaluate.py /tmp/corpus/val/example_000.json
# Compare lnd stack vs the candidate router on a scenario file.
/tmp/routesim --scenarios /tmp/corpus/val/example_000.json --router=lnd --traces=false
/tmp/routesim --scenarios /tmp/corpus/val/example_000.json --router=candidate --traces=false
# Full optimization runs. gepa must be installed from git main — a
# durable clone lives at ~/codez/gepa; prefer uv for the env:
# uv venv /tmp/gepa-venv && uv pip install -p /tmp/gepa-venv \
# "~/codez/gepa[full]"
# Also needs the codex CLI authenticated and OPENAI_API_KEY set.
ROUTESIM_BIN=/tmp/routesim python3 run_gepa.py --corpus /tmp/corpus --name run1 --max-evals 400
ROUTESIM_BIN=/tmp/routesim python3 run_gepa_code.py --corpus /tmp/corpus --name code1
The two optimization modes
- Parameter mode (
run_gepa.py) — candidate = JSON of the existing heuristic's knobs (estimator choice, apriori/bimodal params, attempt cost, min probability). Validates the loop and tunes the current paradigm. - Code mode (
run_gepa_code.py) — candidate = the full Go source ofcandidate_impl.go, an entire routing algorithm implementing therouting.SimRouterinterface. This is the paradigm-free path: the candidate sees only gossip, its own balances, and per-attempt feedback. Compile errors are returned to the proposer as feedback.
Anti-reward-hacking measures
- Candidate routers receive a
SimNetworkViewwrapper, not the concrete graph, so hidden balances and liquidity mutation are unreachable. evaluate_code.pyrejects candidates usingunsafe,reflect,os/exec, network packages, etc.- Selection happens on a val split; a sealed test split is only used for final reporting.
- The source's own channels are rebalanced 50/50 before each batch so scores measure routing skill, not sender funding luck.
Command center
command-center/ holds a static dashboard site (serve with
python3 -m http.server from that directory).