feat(agent): send X-Client version header to our proxy for log attribution (#254)

[cboettig]

What

Sends X-Client: geo-agent/<ref> on requests to our proxy so its logs can attribute a session to the exact build (the client column, currently always null).

• Version source: import.meta.url — the pinned jsDelivr ref the app actually loaded (geo-agent@v3.13.1, or a commit SHA). There's no build step and package.json is stale (1.0.0), so the module URL is the only accurate source. Falls back to dev on a file:// URL (local/headless).

The BYO-endpoint risk this avoids (gating)

geo-agent runs in the browser, so a custom request header extends the CORS preflight. A bring-your-own endpoint whose Access-Control-Allow-Headers is an explicit list without X-Client would have the browser block every request to it — a hard break, not just missing attribution. (The server ignoring an unknown header is harmless; CORS is the actual failure mode.)

So the header is gated: sent only to hosts matching client_header_hosts (default suffix nrp-nautilus.io — the same origin the proxy's own CORS regex trusts), never to external BYO endpoints. Attribution only matters in our logs anyway, so gating costs nothing.

Proxy side is already done

Verified in open-llm-proxy: llm_proxy.py:490 reads x-client → logs it as client; the HAProxy ingress cors-allow-headers already lists X-Client (ingress.yaml:21, with a comment noting it was pre-added for this). So this is purely the client half — no proxy change needed.

Tests

test/agent-client-header.test.js (4 cases): header sent to our proxy, not sent to an external BYO endpoint (auth/content-type unaffected), suffix matching (incl. bare apex, rejects evil-nrp-nautilus.io substring attack and non-URLs), and the client_header_hosts override. Full suite: 489 passing.

Closes #254

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	56.63%	4949 / 8738
🔵	Statements	56.61%	4949 / 8742
🔵	Functions	63.6%	180 / 283
🔵	Branches	83.74%	1082 / 1292

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
app/agent.js	96.1%	85.61%	88.88%	96.1%	87-89, 106-107, 132, 248-250, 257-258, 272-276, 328-333, 342-346, 381-382, 807-808, 879-880, 1005-1007

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