Self-Improvement Agent Harness: A Deterministic SIA Exemplar

Meta → Target → Feedback loops with public/private task splits

Daniel Ari Friedman

1 Abstract

This exemplar documents template_sia, a deterministic implementation of the Self-Improvement Agent (SIA) harness contract described in (AI 2026). The default pipeline replays fixture-backed generations for the mini_classify task; opt-in live mode runs bounded target subprocesses and optional Ollama-backed meta/feedback steps.

Run snapshot. Task mini_classify, run 1, 3 generation(s), live=false. Final accuracy=1.0000 over 6 held-out samples. Values are injected by scripts/z_generate_manuscript_variables.py after analysis.

Keywords: self-improvement agents, benchmark harness, reproducible evaluation, agent loops


2 Introduction

This exemplar ships template_sia, a deterministic research harness for Self-Improvement Agent (SIA) loops (AI 2026). It documents how the template repository separates generic orchestration (infrastructure/sia/) from a reproducible project surface (projects/templates/template_sia/) without vendoring the upstream upstream SIA orchestrator repository.

Compared with the AutoResearch exemplar, SIA focuses on meta → target → feedback generations with public/private task splits rather than candidate-model search and readiness gates. Default CI replays fixture-backed generations; live mode remains opt-in.

Scope. The bundled mini_classify task is a threshold classifier on one feature column. Results demonstrate harness wiring and artifact contracts—not state-of-the-art accuracy.

Run contract. Task mini_classify, run 1, up to 3 generation(s), live=false.


3 Methodology

3.1 SIA loop

The harness implements a three-agent cycle:

  1. Meta — proposes or seeds a target agent for generation \(n\).
  2. Target — runs against public task data and writes agent_execution.json.
  3. Feedback — reads private evaluation metrics and proposes improvements for generation \(n+1\).
Three labeled boxes form a directed cycle from Meta to Target to Feedback and back to Meta, depicting the harness control flow.
Figure 1: Meta → Target → Feedback loop topology for the SIA harness, generated programmatically by write_sia_loop_topology.

Artifacts land under output/runs/run_{id}/gen_{n}/ with target_agent.py, agent_execution.json, optional improvement.md, and canonical results.json.

3.2 Task layout

Each task exposes:

The exemplar task mini_classify is a threshold classifier on a single feature column.

3.3 Determinism contract

When sia.live: false (default), generations replay recorded fixtures from src/fixtures/recorded_generations/. CI never executes generated agent code or calls external LLM APIs.

Pass --live-sia to scripts/run_sia_loop.py for bounded subprocess execution and optional Ollama feedback when a model is configured.

3.4 Per-generation metric overview

The heatmap below provides a compact overview of per-generation accuracy and sample count, enabling at-a-glance comparison across runs.

A two-row heatmap compares accuracy and sample count across 3 generation(s); metric values range from 100.0% to 100.0%, and sample counts range from 6 to 6.
Figure 2: Per-generation metric heatmap showing accuracy and sample count across SIA generations.

4 Results

tbl. 1 summarizes fixture-replay metrics for the bundled run.

Table 1: SIA generation metrics (fixture replay).
Gen Metric Value N
1 accuracy 1.0000 6
2 accuracy 1.0000 6
3 accuracy 1.0000 6

Metric delta (final − first generation): 0.0000.

Final injected token: accuracy=1.0000 (n=6).

A line chart plots 3 accuracy value(s), changing from 100.0% to 100.0%; the observed range is 100.0% to 100.0%.
Figure 3: SIA metric progression across generations.

4.1 Threshold robustness control

The recorded target agents genuinely apply the proposed thresholds 0.5, 0.3, and 0.25. All three lie inside this toy dataset’s clean separation gap and therefore score 1.0. The zero generation-over-generation delta is an important negative result: the harness records feedback and code variation without fabricating an improvement signal where the evaluation cannot distinguish one.

A signed bar chart shows 2 generation-to-generation accuracy change(s): 0 positive, 0 negative, and 2 unchanged; the cumulative change is +0.0%.
Figure 4: Generation-over-generation metric delta (Δaccuracy) for the SIA fixture replay; the flat trace confirms threshold robustness and prevents a fabricated improvement claim.

5 Conclusion

template_sia demonstrates how to embed the SIA harness contract in the Research Project Template without vendoring upstream orchestration code. Layer 1 (infrastructure/sia/) owns task validation, evaluation, context logging, and the generation state machine; Layer 2 wires a minimal classification task, fixture replay, and manuscript tokens.

Non-claims. This tree is a harness and documentation exemplar. Fixture-replay metrics (final accuracy=1.0000) validate wiring only—they are not evidence of state-of-the-art self-improvement. Live self-modification and external LLM calls remain opt-in; default CI never executes generated agent code or claims benchmark parity with (AI 2026).


6 References

See references.bib for BibTeX entries cited in this manuscript, including (AI 2026) and the template repository DOI from manuscript/config.yaml.

AI, Hexo. 2026. Self-Improvement Agents. https://arxiv.org/abs/2605.27276.