* feat(cursor): vision (image_url) input + tool-commit/output-constraint enhancements
Add image/vision input to the Cursor provider's agent.v1 endpoint, plus the
supporting prompt-engineering and resilience work developed alongside it.
Vision input
- Decode OpenAI `image_url` parts (base64 `data:` URIs and remote `http(s)` URLs)
and inline them as `SelectedContext.selected_images[]` — field numbers pinned
from the cursor-agent agent.v1 protobuf descriptor (SelectedImage.data oneof,
uuid, optional Dimension, mime_type). Cross-checked against composer-api's shape.
- New `resolveCursorImages` helper: SSRF-guarded remote fetches via the repo's
canonical `parseAndValidatePublicUrl` (always public-only for client URLs),
<=1 MiB per image (pre-decode + streaming cap), `image/*` enforced, max 12
images, sanitized `CursorImageError` (no stack/path leakage).
- `openai-to-cursor` translator now preserves `image_url` parts instead of
dropping them; executor `buildRequest` resolves images and attaches them to
the user turn. The no-image path is byte-identical to before (test-asserted).
Supporting cursor enhancements
- Tool-commit directive (raises composer-2.5 tool-call rate ~53% -> ~88%),
`tool_choice` none/required/specific handling, and output constraints
(`response_format` / `max_tokens` / `stop` surfaced as prompt instructions).
- `cursorSessionManager`: clear pending tool-call mappings on session close.
- `cursorVersionDetector`: export `FALLBACK_VERSION` as a single source of truth.
Tests & docs
- New unit suite for the image encoder + resolver (field layout, byte-identical
no-image path, SSRF / oversize / bad-base64 / too-many rejections, sanitized
error body), translator image-preservation tests, and live e2e tests
(base64 + remote URL, gated on `CURSOR_E2E_TOKEN`).
- Documented `CURSOR_TOOL_DIRECTIVE` and `CURSOR_IMAGE_FETCH_TIMEOUT_MS` in
`.env.example` and `docs/reference/ENVIRONMENT.md`.
* fix(cursor): address review — redirect SSRF, large-payload guard, stream OOM, case/NaN nits
Resolves the gemini-code-assist review on #3104:
- SSRF via redirect (critical): fetchImageBytes now uses redirect:"manual" and
re-validates every hop through parseAndValidatePublicUrl, so a public URL can't
30x-redirect to a private/link-local address. Bounded to 3 redirects.
- Large data URL (high): reject on raw payload length before the whitespace-strip
regex, so an oversized data URL can't burn CPU.
- Stream read (high): readCapped consumes the body as an async iterable (Node
Readable + Web Streams) or via getReader, capping mid-read; uncapped
arrayBuffer() is only a last resort.
- data: scheme (medium): match case-insensitively (RFC 2397) while preserving the
original payload.
- NaN timeouts (medium): CURSOR_IMAGE_FETCH_TIMEOUT_MS and CURSOR_STREAM_TIMEOUT_MS
fall back to defaults when the env value isn't a positive integer.
Adds tests: redirect-to-private blocked, redirect-to-public followed, too-many-
redirects rejected, uppercase DATA: accepted.
* fix(cursor): defend image fetch against DNS-rebinding SSRF
Address the @codex review on #3104: parseAndValidatePublicUrl only checks the
hostname string, so a public-looking host that (re)resolves to a private /
link-local / metadata IP would still be fetched. Each hop now resolves the host
via dns.lookup({all:true}) and rejects if ANY answer is private (isPrivateHost),
before connecting. IP literals are skipped (already validated by the URL guard).
This narrows but doesn't fully close the TOCTOU window vs fetch's own
resolution; a connection-time IP filter on the shared outbound guard would
close it for every caller. Adds unit tests for the IP gate and a mocked
DNS-rebinding case (public host -> 127.0.0.1, fetch never reached).
