[Ricardo-M-L]

Problem

Image inputs are classified as remote URLs with startsWith('http') in both resolveImageInput and image generate --subject-ref. As a result, ordinary relative paths such as http-assets/frame.png or https-images/reference.png are forwarded as URL strings instead of reading the local file.

This affects, for example:

mmx image generate --prompt "A cat" --subject-ref type=character,image=http-assets/frame.png --dry-run
mmx video generate --model MiniMax-H3 --prompt "A cinematic scene" --image http-assets/frame.png --dry-run

Given an existing PNG at that path, the first command currently emits an image_url pointing at a local relative path; the second places that relative path in its first-frame URL. Neither payload contains the image bytes.

Changes

• Recognize remote image URLs only by the complete http:// or https:// prefix, consistent with the existing toDataUri and media helpers.
• Let other http-prefixed inputs use the existing local-file conversion and validation.
• Keep existing data: and mm_file:// handling in resolveImageInput unchanged.
• Add command-level dry-run regression tests using real temporary PNG files for image subject references and H3 first frames, plus HTTP/HTTPS URL positive controls. The new tests do not make API requests.

Validation

• With the new command tests applied to base 38aba5f: 3 failed, 25 passed; all three failures are the local-path regressions.
• bun test test/commands/image/generate.test.ts test/commands/video/generate.test.ts test/utils/media.test.ts: 33 passed.
• bun run typecheck: passed.
• bun run build: passed.
• git diff --check: passed.
• bun run lint: no errors; one pre-existing no-explicit-any warning at test/sdk/speech.test.ts:117.
• Full bun test: 618 passed, 1 failed. The same failure reproduces in an untouched worktree at 38aba5f (613 passed, 1 failed): Zed configuration > writes a fresh config with the selected model and honors XDG_CONFIG_HOME at test/agent/zed.test.ts:68 on macOS. It expects the XDG directory but receives $HOME/.config/zed/settings.json. No Zed code or test is changed here.

AI-assisted implementation and tests. Two independent agent reviewers reviewed the complete diff separately, reran the focused tests, and reported no blocking findings, following the repository's blind-review instructions.

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