`GET /api/events` is a server-sent-event stream the viewer holds open for the
life of the page. Two signals, two things the browser could not know:
changed source files touched on disk, before any sync — the drift banner
index the graph moved, naming what the sync re-indexed — the live refresh
The server WATCHES and never syncs: the project tree through the engine's own
FileWatcher with a notify-only syncFn, the index through one non-recursive
fs.watch on the data directory settled at 400 ms. Both start with the first
subscriber and stop with the last, so a viewer nobody has open costs no watch
descriptors. Nothing polls, on either side.
Drift is now parity with codegraph_node (#1474) rather than an absence.
`/api/source?ondrift=current` serves a drifted file's CURRENT bytes flagged
`showing: 'current'`, and the three screens that can say so switch off
everything anchored to the old line numbering — gutter ports, call-site links,
call arcs, the callee rail's anchoring — while keeping the source. The banner is
paper-2 with a hairline rule, never amber: amber belongs to the untested badge.
Also fixes a stale read this exposed. A long-lived reader holds an LRU of nodes
by id that only its own writes invalidate, so `/api/node/<id>` kept answering
with a symbol another process's sync had deleted while `/api/search` beside it
said it was gone. GraphSession now drops the read caches when the database (or
its WAL) has been written, and the Symbol view follows a symbol whose id changed
because an edit above it moved its start line, carrying the trail across.
Measured on a live viewer: banner 360 ms after a save, toast 440 ms after
`codegraph sync` returns, 0 requests in 4 idle seconds, and the client gives up
reconnecting after ~90 s with "Not live" rather than hammering a dead port.
Six endpoints under `/api/`, one per screen, each answering in a single
round-trip in the spirit of `codegraph_explore` — the viewer should never
have to ask a follow-up question to finish drawing a pane:
/api/stats index state, graph counts, frameworks
/api/search?q= ranked, kind-grouped symbol search
/api/node/<id> rails, members, tests, blast radius
/api/source?file=&from=&to= verbatim source + a drift verdict
/api/file/<path> outline and import rails
/api/routes URL -> handler, when there is one
It is a reader of the existing schema: no extraction or resolution changes.
It mounts on the `api` seam `startUiServer` already exposed, so it sits
behind the CG-41 loopback boundary — Host allowlist, no CORS headers,
GET/HEAD only — and every read out of the repository goes through
`resolveProjectFile`, ahead of the index lookup so a traversal is refused
as a traversal rather than reported as "not indexed".
Three properties the endpoints are built around:
- No N+1. The engine's busiest symbol has 545 incoming edges; resolving
those one `getNode` at a time is 545 queries. Every edge list is
resolved with one batched lookup, which needed four additive read-only
query methods (`getNodesByIds`/`getFanIn`/`getFanOut` on `CodeGraph`,
plus batched outgoing/incoming edge fetches and unresolved-reference
reads). `/api/node` on `LRUCache.get` answers in ~10 ms.
- Capped lists, honest totals. 545 callers cannot all be rows, so caller
groups cap at 300 — but `total` is always the real number, and the
ordering puts the useful end first (same file, then production code,
then tests). Every count in the payload is the length of a list the
same payload returns, so a badge and its rail cannot disagree.
- Nothing overclaims. Source that drifted on disk since the last index
sync is omitted rather than sliced at line ranges that may now point at
a different symbol; calls that leave the index are counted instead of
silently shortening the callee rail; imports that never resolved are
named; and a test-coverage claim reports whether its search actually
finished. `/api/routes` says a project simply is not routed, and
refuses a `limit` below three because the engine's manifest would
answer that question wrongly.
Tests: 45 against a real indexed fixture over a real loopback server,
covering every endpoint's shape, the drift verdict in all three places it
surfaces, search ranking and the filter grammar, the refusals, and the
capping/latency behaviour at 500 callers. The issue's own acceptance case
— `lru-cache.ts` `get` under 100 ms — runs against this repo's index when
one is present.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Colby McHenry