Append-only log so any future session (Claude or human) can pick up where we left off. Newest entries at the bottom.
Build an MVP evaluation agent for the SDx flow, demonstrable on 2026-05-21.
It is one of three deliverables:
- Eval flow (executable): reads LangFuse trace data → analyzes → writes a learnings markdown report. Lives in
.opencode/,scripts/,eval-reports/. - System documentation (static):
docs/SYSTEM-EXPLAINED.md. Plain language for non-native English readers. - Slide deck (static):
docs/slides.mdrendered with Marp. Minimalist, color used only for meaning, simple language for Japanese audience.
Items 2 and 3 describe item 1 — they are not part of its runtime.
The repo contains no real user names. All worked examples use a synthetic dataset built by scripts/generate_synthetic_traces.py.
| Decision | Choice | Why |
|---|---|---|
| Slide deck format | Markdown + Marp | Plain text in repo; renders to PDF/HTML/PPTX; easy to diff. |
| Data source for MVP | CSV file (LangFuse export format) | Zero infra, deterministic, demo-safe. Live LangFuse API can come in v2. |
| Worked example | Synthetic toy dataset at data/synthetic-traces.csv |
Demonstrates the format and signals end-to-end without exposing real users. |
| Flow shape | One agent + one skill | .opencode/agent/evaluator.md orchestrates; .opencode/skills/langfuse-trace-analysis/SKILL.md holds reusable schema knowledge, loaded on-demand. Matches opencode conventions. |
| Report content | Structural + qualitative + FLAME-style implicit signals | Aligns with the team's research direction. Structural signals are easy to compute; implicit signals are detected from message patterns; qualitative learnings are LLM-generated. |
The LangFuse export has 15 columns. Two trace name values matter:
ai.streamText= opencode-side traces with full content (system prompt, messages, tool_calls, finish_reason, headersUser-Agent: opencode/1.4.0, session affinity). These are the rows the eval agent uses.llm_request= vLLM OpenTelemetry telemetry only (latency/token counts, no content). Useful for cost rollups, not for learnings.
The eval flow filters to name == 'ai.streamText' and groups by sessionId to build a per-session "trace packet."
The synthetic dataset (data/synthetic-traces.csv, 8 rows, 1 session) follows the same schema so the loader handles it identically to real exports.
- ✅ Set up project skeleton and ACTION_LOG.md
- ✅ Build
scripts/load_traces.py - ✅ Validate loader on real-format CSV
- ✅ Write
.opencode/skills/langfuse-trace-analysis/SKILL.md - ✅ Write
.opencode/agent/evaluator.md - ✅ Wire up
opencode.json - ✅ Produce a sample report by hand-running the flow
- ✅ Write
docs/SYSTEM-EXPLAINED.md - ✅ Write
docs/slides.md(Marp deck) - ✅ Final pass: update ACTION_LOG and tell user how to run
- ✅ Build
scripts/generate_synthetic_traces.py - ✅ Replace sample report with one from synthetic data
- ✅ Scrub people's names from all repo files
- ✅ Update slides + system doc to use synthetic toy case
- ✅ Update ACTION_LOG with refactor entry (this entry)
- Read all three input files (SDX Ideas md, the source pptx, sampled the LangFuse CSV).
- Confirmed opencode conventions via opencode.ai/docs (agents/, skills/, tools/).
- Confirmed four scoping decisions (logged in the Decisions table above).
- Created task list and this action log.
- Repo skeleton created:
.opencode/agent/,.opencode/skills/langfuse-trace-analysis/,scripts/,docs/,eval-reports/.
- Wrote
scripts/load_traces.py. Three modes:--list,--session,--out-dir. - Confirmed
csv.field_size_limit(sys.maxsize)handles 100+ MB rows. - Filter is
name == 'ai.streamText'(configurable via--name). - Built and inspected a packet from a real-format export to confirm the JSON shape: ~70 KB for a typical 22-turn session, including system prompts deduplicated by hash, normalized turns, and rolled-up token totals.
- Wrote skill at
.opencode/skills/langfuse-trace-analysis/SKILL.md. Defines trace shape, six implicit-signal detectors (user correction, retry, abandoned trajectory, follow-up edit, context bloat, tool failure echo), and the report layout. - Wrote agent at
.opencode/agent/evaluator.md. Mode: primary. Loads the skill on every run as the source of truth. - Wrote
opencode.jsonregistering the agent and pre-allowing thelangfuse-trace-analysisskill.
- Wrote
docs/SYSTEM-EXPLAINED.md. Plain-language, short sentences for non-native English readers. Numbered sections + glossary. - Wrote
docs/slides.md. Marp deck. Color reserved for meaning: blue=system, amber=data, red=problem, black=text. Minimalist; no decorative imagery.
- Per request: removed all real user names from the repo, and built a synthetic toy dataset to anchor the worked examples.
- Wrote
scripts/generate_synthetic_traces.py. Emits one session in LangFuse export format (data/synthetic-traces.csv, 8 rows). Trace IDs are deterministic (tr_0001_codegraph…tr_0008_done) so docs can cite them. - The toy task: "Add YOLO object detection to the rear camera module."
Designed to surface three signals: a user correction
(
tr_0004_correction), a tool failure echo (tr_0006_write2_retry, the assistant text echoes "permission denied"), and a retry (tr_0005_write1→tr_0006_write2_retry, samewritecall repeated with identical inputs). - Deleted the prior real-data sample report. Wrote a new one against the
synthetic packet at
eval-reports/ses_synthetic_camera_obj_det_001_20260509T140500Z_learnings.md. - Scrubbed names from
docs/SYSTEM-EXPLAINED.md,docs/slides.md,.opencode/agent/evaluator.md,.opencode/skills/...SKILL.md. TheSDX Ideas related to evaluation.mdfile is the team's input document and is left unchanged.
-
Run the eval flow live (in opencode):
cd <repo> opencode # press Tab, pick `evaluator`, then say: # "Evaluate session ses_synthetic_camera_obj_det_001 # in data/synthetic-traces.csv"
-
Regenerate the toy dataset:
python3 scripts/generate_synthetic_traces.py --out data/synthetic-traces.csv
-
Run the loader directly (no LLM, just data prep):
python3 scripts/load_traces.py --csv data/synthetic-traces.csv --list python3 scripts/load_traces.py --csv data/synthetic-traces.csv \ --session ses_synthetic_camera_obj_det_001 > /tmp/packet.json -
Preview the slide deck:
npx @marp-team/marp-cli docs/slides.md -o docs/slides.html npx @marp-team/marp-cli docs/slides.md -o docs/slides.pdf npx @marp-team/marp-cli --watch docs/slides.md # live preview npx @marp-team/marp-cli docs/slides.md --pptx -o docs/slides.pptx # PowerPoint export
- LangFuse export size: the SDX Ideas doc flags this. The team has suggested using LangFuse's built-in scoring/cost API instead of dumping raw JSON. Worth a 30-min spike before 5/21 to see if a smaller endpoint makes the loader unnecessary.
- Should the loader also process
llm_requestrows for cost/latency rollups in a future report variant? (Currently ignored.) - Cross-session trend reports (mentioned as v2) — we have the per-session packets; rolling them up is one more script, not a new system.
- The three input materials (real LangFuse CSV export, the source pptx,
and the team alignment markdown) all contained real names. Per request,
they were moved out of the repo to a sibling folder:
../eval-agent-inputs/(i.e./Users/ryan/Desktop/eval-agent-inputs/). - The repo is now fully name-free. Confirmed via grep across all files.
- The synthetic dataset (
data/synthetic-traces.csv) and the worked example report (eval-reports/ses_synthetic_camera_obj_det_001_20260509T140500Z_learnings.md) are now the canonical demo materials. They cover the full flow end-to-end without referencing the original inputs.
- Replaced the lightweight text flow on the slides' "The flow" slide with a vertical pipeline diagram drawn in HTML/CSS. Three stages stacked (Capture / Evaluate / Improve), boxes are color-coded by meaning (blue = system, amber = data, gray = actor).
- Added matching ASCII and Mermaid diagrams to
docs/SYSTEM-EXPLAINED.mdsection 3, plus a stage-summary table. - Mermaid block uses the same color classes so the rendered diagram matches the slides when viewed on GitHub or in any Mermaid-aware Markdown viewer.
- Convention is now
eval-reports/<session_id>_<YYYYMMDDTHHMMSSZ>_learnings.md. - Re-evaluating the same session no longer overwrites prior reports; each run gets a unique, sortable file name.
- The
_learnings.mdsuffix makes the file's purpose obvious in a directory listing. - Updated:
.opencode/agent/evaluator.md,.opencode/skills/langfuse-trace-analysis/SKILL.md,docs/SYSTEM-EXPLAINED.md,docs/slides.md, ACTION_LOG references. - Renamed the existing sample report to follow the new convention.
- Replaced the tutorial-style deck with a 7-slide academic-register presentation: Title · Problem · Method · Architecture · Demonstration · Integration · Roadmap.
- Each slide carries an italicized thesis line, a numbered section label, and a Helvetica running header / footer for institutional feel. Body type changed to a serif (Garamond/Georgia) for academic register; labels and code stay sans-serif for hierarchy.
- Method slide defines the three signal classes (structural, qualitative, implicit / FLAME-style) with explicit method tags.
- Demonstration slide reports the toy-session findings as an evidence table (signal · trace ID · type) and includes a "Limitation" call-out pointing to real-session validation in the roadmap.
- Added an Integration slide: file-name convention; closed loop showing reports → eval-reports corpus → knowledge-layer vector index → future agent context. Establishes that the evaluator's output is itself a knowledge artifact ingested by the same machinery as requirements, specs, and FDA/ASPICE documents.
- Added a Roadmap slide split into "before the demo" and "beyond MVP".
- Color meaning preserved (system / data / problem / mute). Color is used only for those four classes; everything else is black on white.
- Read this file top-to-bottom; everything's here.
- All deliverables are in this directory tree.
- The synthetic dataset and worked example let you run the flow without any external data. opencode 1.4.0 is the only external dependency.
- Original input materials (CSV, pptx, alignment doc) live at
../eval-agent-inputs/if needed for reference.