[AAASM-4122] 🔒 (install): Replace claimable .io install host with canonical agent-assembly.com

[Chisanan232]

Description

The Python SDK's runtime install hint fetched a shell script from get.agent-assembly.io and piped it straight into a shell. Both get.agent-assembly.io and the apex agent-assembly.io resolve to NXDOMAIN — the .io domain is unregistered and claimable. Any third party could register agent-assembly.io, host a malicious script at get., and gain arbitrary code execution on every user/CI that follows the hint (classic claimable-domain supply-chain footgun; no checksum or signature gate).

This PR repoints the hint at the canonical https://agent-assembly.com/install.sh, which is registered (Cloudflare) and whose installer SHA256-verifies release tarballs against SHA256SUMS. The brew-tap and pip install channels already listed in the hint (fixed under AAASM-4072) are unchanged and remain the preferred first options.

Two shipped modules emit this hint:

• agent_assembly/runtime.py (INSTALL_HINT)
• agent_assembly/_install.py (INSTALL_HINT)

Recommendation for the org: defensively register agent-assembly.io (and get.agent-assembly.io) to close the claimable-domain window permanently.

The examples repo carries the same stale hint and is fixed in a separate PR under this ticket (ai-agent-assembly/agent-assembly-examples).

Type of Change

• 🔧 Bug fix

Breaking Changes

• No

Related Issues

• Related JIRA ticket: AAASM-4122

Testing

• Manual testing performed
• No tests required (explain why)

String-literal-only change to the printed install hint. Existing tests assert on the INSTALL_HINT symbol (not the literal URL) and continue to pass: pytest test/ -k "install or runtime" → 74 passed, 10 skipped. ruff check on the touched files is clean; ruff format --check reports already-formatted; pre-commit (ruff/black/isort/mypy) passed on the touched files. (Repo-wide ruff/mypy baseline noise from generated *_pb2.pyi stubs and the optional-unbuilt agent_assembly._core native module is pre-existing and unrelated.)

Checklist

• Code follows project style guidelines
• Self-review completed
• Comments added for complex logic
• Documentation updated if needed
• All tests passing

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Chisanan232]

Senior review — APPROVE-READY (comment only, not an approval)

Verdict: LGTM. Clean, correctly-scoped fix for the HIGH claimable-domain RCE (AAASM-4122).

1. CI: Green — 19/19 checks pass. No failures to triage.

2. Scope vs ticket: Full coverage of the shipped-SDK portion of AAASM-4122. Both offending sites replaced:

• agent_assembly/_install.py:35 and agent_assembly/runtime.py:42 now emit https://agent-assembly.com/install.sh | sh.
• git grep confirms zero residual agent-assembly.io / get.agent-assembly anywhere in the repo.
• The replacement points at the ticket's designated canonical host: agent-assembly.com/install.sh (Cloudflare-served, installer-drift-gated, SHA256SUMS-verified). Matches the ticket's prescribed fix.
• The examples-repo edit (run-with-aasm.sh, README) is correctly tracked as its own separate PR per the ticket — out of scope here.

3. Side effects: None. Install-hint string constants only — no code path, control flow, or public API changed. _install.py (used for the not-installed error hint) and runtime.py both changed in lockstep, so the messaging stays consistent.

4. FE: N/A.

Local validation (worktree @ 4b19067): pre-commit gate green — isort / autoflake / black / mypy all Passed; ruff check on both changed files All checks passed.

Independence: touches only _install.py + runtime.py — disjoint from #213 (assembly.py / runtime_interceptor.py) and #214 (transport_security.py / release-python.yml). Independently mergeable.

Note the ticket's standing recommendation to defensively register agent-assembly.io at the org level — orthogonal to this code fix.

— Claude Code