Cache download-files in Dockerfile by using the module-level command

[aryeila]

Overview

Update the Dockerfile to use the module-level download-files command introduced in livekit-agents@1.5.10. The download step now runs before COPY . ., so the layer caches across code-only changes — editing your agent no longer triggers a re-download of plugin model files.

Change

RUN uv run "src/agent.py" download-files (after COPY . .) → RUN uv run --module livekit.agents download-files (before COPY . .).

The new command discovers installed livekit-plugins-* packages and runs their download_files() step without loading your agent code. That's what allows the step to move ahead of the source copy.

livekit-agents is pinned to 1.5.12 in pyproject.toml, which is past the 1.5.10 threshold for the module-level command.

Related PRs

This is part of a coordinated rollout across four repos. Each PR updates one slice of the same migration.

• Docs: livekit/web#4545
• CLI templates: Cache download-files in Dockerfile templates by using standalone commands livekit/livekit-cli#848
• Python starter (this PR): Cache download-files in Dockerfile by using the module-level command #79
• Node.js starter: Cache download-files in Dockerfile and simplify the download-files script agent-starter-node#49

Upstream SDK changes:

• Python: feat: support python -m livekit.agents.download for asset fetching livekit/agents#5738 (livekit-agents@1.5.10)
• Node.js: feat: livekit-agents download-files script to optimize Docker layers livekit/agents-js#1511 (@livekit/agents@1.4.3)