contember/agent-canvas/canvas

Session

Resolve the canvas session ID once, then reuse the literal value for the entire workflow:

echo "${CANVAS_SESSION_ID:-${CODEX_THREAD_ID:-${CLAUDE_CODE_SESSION_ID:-$(uuidgen)}}}"

Write the printed value into every canvas command as --session "<id>", and store canvas files in ${TMPDIR:-/tmp}/agent-canvas/<id>/.

Do NOT rely on export — in some hosts (Claude Code) each shell call starts fresh, so the variable will not survive between commands.

Instructions

Always use absolute filesystem paths for local file references in canvas components (such as FilePreview), and verify that the referenced files exist. Resolve them against the user's project directory, not the temporary directory containing the JSX.

Run these commands from the user's project root before using Canvas:

bunx agent-canvas instructions
bunx agent-canvas instructions --list

Getting detailed docs: Run bunx agent-canvas instructions <topic> for detailed documentation on any component or flow. For example: bunx agent-canvas instructions component-mermaid or bunx agent-canvas instructions flow-feature.