feat(integrations): add free Parallel Search MCP

[georgeatparallel]

• A human has tested these changes.

HUMAN: Rowan reported on September 21, 2026 that his local merge and catalog rebuild passed 984 tests plus the live Parallel search/fetch test. No hosted UI testing is claimed.

Why

This adds free, keyless web search and page fetching to the shared integration catalog. OpenHands users can add Parallel Search through the normal MCP settings instead of entering its URL manually. I'm George from Parallel.

For context, Parallel Search Fast scores 80 F1 on Artificial Analysis's DeepSearchQA benchmark, and its Time per Task chart reports 18.5 seconds per task. Fast is also the mode used by anonymous Search MCP. These are search API benchmark results, not measured OpenHands performance.

Summary

• Add an opt-in, no-auth Streamable HTTP entry for Parallel Search MCP and regenerate the JavaScript index.
• Update the public-server allowlist and add an opt-in live test for search, page fetching, source links and invalid arguments.
• Preserve existing integrations, search defaults and saved settings.

Issue Number

Fixes #604

How to Test

uv sync --group test
npm run build:integrations
uv run pytest -q
RUN_PARALLEL_MCP_LIVE=1 uv run pytest -q tests/test_live_integration_smoke.py -k parallel

Validation after merging upstream main and regenerating the integration index on September 21, 2026: Python 3.12.13 with openhands-sdk 1.49.2 passed 985 tests, with 25 skipped. The anonymous live Parallel test passed search, page fetching, source-bearing results and invalid arguments. Extension sync and deprecation checks also passed; extension sync reported an existing non-blocking marketplace coverage warning for plugins/issue-duplicate-checker.

Earlier validation with this package linked into Agent Canvas passed 52 focused component/helper tests, including credential-free installation and preservation of sibling servers. Those consumer tests were not rerun for this merge, and the full hosted UI was not exercised.

With this catalog version installed in Agent Canvas, open MCP settings, choose Parallel Search from the marketplace and add its no-auth connection. It uses https://search.parallel.ai/mcp and requires no API key. The enabled server exposes web_search and web_fetch through the existing MCP tool path.

Video/Screenshots

No hosted UI recording was captured for this catalog and test change.

Notes

Search queries and fetched URLs are sent to Parallel's hosted service. Anonymous Search MCP is free for light use and rate-limited; model and hosting costs still apply. Availability in released clients follows the catalog release and consumer update.

[all-hands-bot]

👋 This PR needs a couple of things fixed before OpenHands can review it:

• the PR description's HUMAN: section needs at least 20 characters describing what you tested, not just the template placeholder

Push an update once this is addressed and this check re-runs automatically.

This is an automated check - no AI was used to generate this comment.

[all-hands-bot]

🚦 CI is currently failing on this PR's latest commit.

Please fix the failing checks before OpenHands reviews it - this is re-checked automatically once you push a new commit. (A maintainer can also request @all-hands-bot as a reviewer to have it reviewed regardless of CI status.)

This is an automated check - no AI was used to generate this comment.

[georgeatparallel]

I've merged current main and regenerated the integration index in 38fe194. Local validation on Python 3.12 passed 985 tests (25 skipped), and the anonymous Parallel search/fetch smoke test passed. The PR description now records the fresh results and Rowan's earlier local test report without claiming hosted UI testing.

Could a maintainer add enhancement to #604? The readiness bot says that missing type label is the blocker; its existing Desired Behavior and Acceptance Criteria sections meet the enhancement criteria.

The fresh Tests, Check Extensions, and Deprecation deadlines runs also require approval for this fork. Could you approve those workflows? Once the readiness gate and CI pass, I'd appreciate a review of this catalog addition.