# Session 0017.1 — Subsession transcript > Parent: SESSION-0017.0-TRANSCRIPT-…md (not yet written; driver writes > at end of session 0017.0) > Date: 2026-05-28 > Goal: rfc-app v0.19.0 — /docs/sessions browser + flyout nav (roadmap > item #30) > Outcome: **Shipped on branch `feature/v0.19.0-docs-sessions-browser` > at `477f496`. Backend mediates `/api/docs/sessions/{manifest,about, > /index, /}` with an in-process TTL cache (60s > manifest, 5min content; both env-tunable + negative-cached on 404). > Frontend reorganizes `/docs` into a left-flyout hub with the new > session browser sub-routes; existing DOCS.md content moves to > `/docs/user-guide`. 313/313 backend tests pass (18 new); frontend > builds clean. No tag, no pin bump, no benstull mirror push — driver > takes over after subsession 0017.2 lands.** --- ## Pre-session state - `rfc-app` was at `main @ ac3513a`, VERSION `0.18.0`, working tree clean. Two remotes: - `origin` → `git.wiggleverse.org/ben.stull/rfc-app` (canonical) - `benstull` → `git.benstull.org/benstull/rfc-app` (mirror) - The most recent release on `main` was v0.18.0 (email + webhook hygiene, roadmap items #18 + #20). - Existing `/docs` surface was the v0.14.0 single-route DOCS.md shape: `components/Docs.jsx` rendering markdown via the shared `MarkdownPreview` (marked + lazy-loaded mermaid). Backend served the body at `/api/docs` from a disk-cached `DOCS.md` at the repo root. - Dispatch settled two design choices before this subsession opened: the transcript repo is gitea-only (canonical at `git.wiggleverse.org/wiggleverse/ohm-session-history`, no GitHub mirror) and the rendering shape is runtime fetch with cache (no build-time bundling of transcripts). --- ## Turn-by-turn arc ### Arc 1 — Orientation Read `~/git/ohm-infra/SESSION-PROTOCOL.md` (full), `rfc-app/CLAUDE.md`, the SPEC §21 analytics chapter (DOM patterns + the autocapture attribute conventions), `backend/app/docs.py` and `backend/app/api.py` (to see how the existing v0.14.0 `/api/docs` was wired), and `backend/tests/test_propose_vertical.py` for the `app_with_fake_gitea` fixture shape that every existing test reuses. Noted that `pyproject.toml` doesn't exist in rfc-app (the dispatch prompt's "bump pyproject.toml" instruction was a non-op — there's a `backend/requirements.txt` only, and the canonical version sources are `VERSION` + `frontend/package.json#version` per SPEC §20.1). ### Arc 2 — Design choice: per-session listing The dispatch prompt named the open design question for the per-session index page (`/docs/sessions/:nnnn`). Two options: 1. Extend the manifest endpoint to also list per-session filenames via the gitea contents API. 2. Add a separate per-session listing endpoint that hits gitea contents only when the session-index page is visited. I went with **option 2** (separate `/api/docs/sessions//index` endpoint). Reasoning: the manifest stays cheap and small (one fetch, one cache entry, 60s TTL); per-session listings are fetched on demand and cached at the content TTL (5min). This means a user who only browses the flyout's session list (via the manifest) doesn't pay for `N` extra gitea contents-API calls — only the user who clicks into a session pays. The endpoint filters the contents-API response to entries matching the `_TRANSCRIPT_FILENAME_RE` so any sibling files in a `NNNN/` folder (e.g. an attached `notes.md`) don't show up in the list. ### Arc 3 — Design choice: negative caching for 404s The dispatch prompt left negative caching for 404s as optional. **Decided to implement it**: cache 404 results at the content TTL across the manifest, about, transcript, and session-index endpoints. Reasoning: at v0.19.0 ship time, the parallel ohm-session-history repo restructure (subsession 0017.2) hasn't shipped yet — the repo is still flat, so the manifest, about, session-index, and per-transcript fetches will all 404 from gitea for the first few hours / days. Without negative caching, every page-view in that window would trigger a fresh gitea request even though we already know it's 404. With negative caching, repeated visits to a known-missing transcript only hit gitea once per 5-minute window. Manifest 404 cache means the first OHM user loading `/docs/sessions/*` doesn't hammer the upstream while 0017.2 is still mid-flight. The behavior is exercised by `test_transcript_404_is_cached` in the new test file. ### Arc 4 — Backend slice Wrote `backend/app/docs_sessions.py` (the fetcher + cache module) and added four routes to `backend/app/api.py`: - `GET /api/docs/sessions/manifest` — returns `sessions.json` as a JSON object. 404 from gitea → `{}` at HTTP 200 (empty-state contract, lets the frontend short-circuit without an error banner). 5xx / timeout → HTTP 502 with `{detail: {error, detail}}`. - `GET /api/docs/sessions/about` — returns README.md as `text/markdown; charset=utf-8`. 404 → HTTP 404; 5xx → 502. - `GET /api/docs/sessions/{nnnn}/index` — returns `{"files": [...]}`. The path param `nnnn` must match `^\d{4}$`; otherwise 400 before any network call. 404 from gitea (no such folder) → HTTP 404. - `GET /api/docs/sessions/{nnnn}/{filename}` — returns the transcript body. Both path params are regex-validated before the network call (`^\d{4}$` for nnnn, `^SESSION-\d{4}\.\d+(\.\d+)*-TRANSCRIPT(---)?\.md$` for filename — `--` is optional so legacy renamed- letter transcripts without timestamps remain reachable). Returns the body as `text/markdown; charset=utf-8`. The fetcher uses `httpx.AsyncClient` with a 5s timeout and no auth header (the gitea repo is public). The cache is plain `dict` keyed by URL-path + `time.monotonic()` checks; the `_lock` is a `threading.Lock` so the cache is safe under FastAPI's worker thread pool. Env knobs: - `OHM_SESSION_HISTORY_RAW_BASE` (default points at `wiggleverse/ohm-session-history` on git.wiggleverse.org) - `OHM_SESSION_HISTORY_CONTENTS_BASE` (default mirrors the raw base on the contents-API mount) - `OHM_DOCS_SESSIONS_MANIFEST_TTL_SEC` (default 60) - `OHM_DOCS_SESSIONS_CONTENT_TTL_SEC` (default 300) ### Arc 5 — Backend tests + the monkeypatch ordering snag Wrote 18 new tests in `backend/tests/test_docs_sessions_vertical.py`. The tricky bit took a couple iterations to nail: The shared `app_with_fake_gitea` fixture from `test_propose_vertical.py` monkeypatches `httpx.AsyncClient` via `monkeypatch.setattr("app.gitea.httpx.AsyncClient", patched)`. Since `app.gitea.httpx` IS the shared `httpx` module, that setattr mutates the global `httpx.AsyncClient` attribute. My docs-sessions test fixture then did the same for `"app.docs_sessions.httpx.AsyncClient"` — meant to override — but the first version captured `real_client_cls = httpx.AsyncClient` at fixture-setup time. At that point `httpx.AsyncClient` was already the gitea-patched wrapper, so my "patched" function ended up wrapping the gitea-patched wrapper, and gitea-bound requests still routed through the FakeGitea handler (and the FakeGitea returned 404 for session-history URLs, making my test see "manifest empty"). Fix: import the truly-unpatched `AsyncClient` from `httpx._client` and use that as the base inside my install closure. The `_UpstreamHandler` also gained a host-marker filter so it only counts session-history URLs (not the reconciler's incidental Gitea calls that also hit our handler via the shared httpx module) in its `.calls` list — that lets the cache-hit assertions stay exact. Test inventory after the fix lands: - Manifest happy-path / empty-state / 502 - About happy-path / 404 / 502 - Transcript happy-path / 404 / 502 - Path-validation rejection: invalid nnnn, path-traversal, legacy flat-root filename — all rejected 400 before network - Session-index happy-path / 404 / invalid-nnnn rejection - Cache-hit-within-TTL for manifest + transcript - Negative cache for transcript 404s All 18 pass; full backend suite is **313/313**. ### Arc 6 — Frontend slice The dispatch prompt was specific about reusing the existing markdown renderer (`MarkdownPreview` — marked + mermaid lazy-load), so the four new sub-route components each render their body through that same component. No new markdown library. Component layout: - `DocsLayout.jsx` — shell with the flyout nav + `` for sub-routes. Owns the manifest fetch + the mobile-drawer toggle. - `DocsUserGuide.jsx` — DOCS.md content (the old `/docs` route). - `DocsSessionsAbout.jsx` — renders the session-history README. - `DocsSessionIndex.jsx` — per-session transcript list. Fetches the manifest (for the title) AND the per-session index endpoint (for the file list). Treats title-fetch failure as decorative (just renders the bare `Session NNNN` header) while the file-list fetch is the load-bearing one. - `DocsSessionTranscript.jsx` — renders a single transcript. `App.jsx` route registration replaced the single `Route path="/docs"` with: ``` /docs → Navigate to /docs/user-guide /docs/* → DocsWithSidebar (nested Routes inside) ├── /user-guide ├── /sessions → Navigate to /sessions/about ├── /sessions/about ├── /sessions/:nnnn └── /sessions/:nnnn/:filename ``` Mobile drawer: at viewport ≤ 720px the sidebar is hidden by a `transform: translateX(-100%)` and revealed via a `☰` button in the header. A scrim overlay (`.docs-drawer-scrim`) intercepts outside clicks. The drawer auto-closes on every route change (via a `useEffect` keyed on `location.pathname`) so a click in the flyout doesn't strand the user on a drawer-open view. Analytics (per SPEC §21): - Added `EVENTS.DOC_VIEWED` to `frontend/src/lib/analytics.js` (new constant, taxonomy entry per §21.1's "new events SHOULD land via a release"). Each sub-route component fires `track(EVENTS.DOC_VIEWED, { section: '...' })` on mount. - Every interactive nav element (links, buttons) carries `aria-label` + `data-amp-track-name` so autocapture rows are readable per §21.3. The per-row session links also carry `data-amp-track-session={nnnn}` so the dashboard can aggregate by session. The old `Docs.jsx` is now dead code; deleted in the same commit. ### Arc 7 — Version bumps + CHANGELOG + push Bumped `VERSION` (root) and `frontend/package.json#version` from `0.18.0` → `0.19.0`. The dispatch prompt named `pyproject.toml` but there isn't one in this repo (the backend uses a plain `requirements.txt`); noted in this transcript but no edit performed. `frontend/package-lock.json` still reads `0.15.0` — it has been drifting since the v0.15.0 release (four minor versions). Not touched in this release (separate cleanup; see §19.2 candidates). CHANGELOG entry was prepended above the v0.18.0 entry verbatim per the dispatch prompt (header date, body paragraph, upgrade- steps MAY block, degradation note about the parallel session-history restructure shipping in subsession 0017.2). Three commits on the feature branch, pushed to origin only: - `39e5770` v0.19.0 backend: /api/docs/sessions/* endpoints + TTL cache - `822f426` v0.19.0 frontend: /docs/* route tree + flyout nav + sessions browser - `477f496` Release v0.19.0: /docs nav + on-site sessions browser `benstull` mirror untouched per dispatch. --- ## Cut state | | | | --- | --- | | rfc-app | feature/v0.19.0-docs-sessions-browser @ `477f496`, pushed to `origin` only | | Tests | pytest backend: **313 passing** (18 new in test_docs_sessions_vertical.py); frontend has no test framework — `npm run build` is green | | Frontend dev-server smoke check | Skipped (subsession is a sandboxed agent, no browser to drive). The CHANGELOG-named degradation path is structurally exercised by the backend's 404 → frontend's empty-state contract; route-mount errors would have surfaced at `npm run build` | | What the driver does next | tag v0.19.0 after 0017.2 lands → merge to main → push to origin + benstull mirror → bump ohm-rfc pin → `flotilla deploy ohm-rfc-app` → verify /docs/user-guide + /docs/sessions/about surfaces in the deployed environment | --- ## §19.2 candidates surfaced 1. **`frontend/package-lock.json` version drift** — what / lock reads `0.15.0` while `package.json` is now `0.19.0` (the lock has been stale since the v0.15.0 release). why / it's an audit-log inconsistency in the npm metadata. when / one-shot cleanup, low-priority — the lock doesn't affect builds because the resolved versions are correct, just the top-level `name` stanza. Fix in the next session that touches frontend deps. 2. **rfc-app backend has no `pyproject.toml`** — what / the dispatch prompt assumed a `pyproject.toml` exists; the repo uses a plain `backend/requirements.txt`. why / standard Python tooling (uv, hatch, ruff config, mypy config) all prefer pyproject.toml; absence makes those tools less ergonomic. when / a session that brings in another tool that wants the file. Could pair with a §20.1-style canonical-source audit ("VERSION here, pyproject.toml there — which wins?"). 3. **`docs_sessions.py`'s private symbols leak into `api.py`** — what / I called `docs_sessions._is_valid_session_dir` and `docs_sessions._is_valid_transcript_filename` from the route layer (underscore-prefixed names). why / the validation is load-bearing for path-traversal rejection and shouldn't be re-implemented in the route, but exporting two helpers vs. one consolidated `validate_path(nnnn, filename) -> bool` would keep the API cleaner. when / next docs-sessions touch. 4. **CHANGELOG entry header style drifted** — what / the v0.18.0 entry header is `## 0.18.0 — 2026-05-28` (no `v` prefix); my new v0.19.0 entry is `## v0.19.0 — 2026-05-28` (with `v` prefix) — I followed the dispatch prompt's verbatim block. why / cosmetic inconsistency in the changelog history. when / a release that audits the file for consistency could rename one direction or the other. 5. **`docs_sessions` cache cannot be invalidated externally** — what / the in-process cache exposes `reset_cache()` but no "invalidate this URL" gesture. why / if the operator publishes a transcript correction and the cache has the old body, they wait up to 5 minutes for the next reader to see the fix. when / a session that wires the reconciler's existing periodic refresh gesture in `cache.py` to also tick this module — or that adds an admin POST `/api/docs/sessions/refresh` for an explicit bust. Low priority; the publish gesture is rare. --- ## Notes for the driver - **Path-traversal corner**: FastAPI / Starlette normalizes `..` in the URL path before routing, so `/api/docs/sessions/0001/../etc/passwd` resolves to a path that doesn't match the `/api/docs/sessions/{nnnn}/{filename}` route. The defense-in-depth is still in place (regex validates `nnnn` AND `filename` before any network call), but the test for path traversal had to use `etc%2Fpasswd` (URL-encoded slash) to actually reach the handler — the bare `../etc/passwd` was 404'd by the router itself. - **TestClient + lifespan**: the backend tests use `with TestClient(app) as client:` which triggers the FastAPI lifespan. That starts the reconciler, which makes Gitea calls that ALSO hit our patched `httpx.AsyncClient` (since httpx is a shared module — see Arc 5). The `_UpstreamHandler` filters its `.calls` list to session-history URLs to keep the cache-hit assertions exact. Reconciler hits return 404 (no matching key in the responses dict), which the reconciler logs as a warning and proceeds — harmless for our test surface. - **Frontend dev-server check not run**: the dispatch prompt named this as optional. The subsession is a sandboxed agent without a browser to drive; the build's success and the route registration's symmetry with the existing `/philosophy` chrome is the closest analog I could verify. Recommend the driver run `npm run dev` against the feature branch before merging to spot-check the flyout's render + drawer toggle on a real viewport. - **No tag, no pin, no mirror push** — per dispatch. Driver handles tag → ohm-rfc pin bump → flotilla deploy after 0017.2 lands.