Summary

Cyrus currently has no way to configure the Claude Agent SDK's reasoning effort level (low / medium / high / max). The capability exists in every layer beneath cyrus, but the edge worker doesn't plumb it through.

Current state (v0.2.44)

So the whole stack could carry an effort value — cyrus just never reads one from config.

Also, RunnerSelectionService.determineRunnerSelection() only parses [agent=...] and [model=...] description tags — no effort tag.

Proposed change

Match the existing model selection precedence:

1. Description tag — [effort=low|medium|high|max] in the Linear issue description
2. Issue label — effort-low, effort-medium, effort-high, effort-max
3. Per-repository config — repository.extraArgs.effort (or a dedicated repository.effort field) in ~/.cyrus/config.json
4. (Optional) Global default — claudeDefaultEffort alongside claudeDefaultModel

Only applies to the Claude runner (the SDK's effort knob is Claude-specific).

Proposed code changes

RunnerSelectionService.ts — parse effort from description/labels and return it:

const descriptionEffortTagRaw = this.parseDescriptionTag(normalizedDescription, "effort");
const resolveEffortFromLabel = (lowercaseLabels: string[]) => {
  for (const lvl of ["low", "medium", "high", "max"] as const) {
    if (lowercaseLabels.includes(`effort-${lvl}`)) return lvl;
  }
  return undefined;
};
let effortOverride = (descriptionEffortTagRaw || "").toLowerCase().trim()
  || resolveEffortFromLabel(normalizedLabels);
if (effortOverride && !["low","medium","high","max"].includes(effortOverride)) {
  effortOverride = undefined;
}
if (runnerType !== "claude") effortOverride = undefined;

return { runnerType, modelOverride, fallbackModelOverride, effortOverride };

RunnerConfigBuilder.ts — stop hardcoding extraArgs, merge from repo config and selector:

...(runnerType === "claude" && {
  extraArgs: {
    chrome: null,
    ...(input.repository.extraArgs || {}),
    ...(runnerSelection.effortOverride ? { effort: runnerSelection.effortOverride } : {}),
  },
}),

This also unlocks repository.extraArgs as a general escape hatch for any future Claude Code CLI flag (--agent, --betas, etc.) without needing code changes each time.

Use cases

• A user on a Max plan wants Opus + effort=max for heavy refactoring on one repo, and Sonnet + effort=low for routine triage on another.
• Per-issue: a one-off research task tagged [effort=max] vs typical issues defaulting to high.
• Cost control: teams running many concurrent sessions can default to effort=medium globally while letting specific hard issues opt into max via description tag.

Notes

I've applied this patch locally to cyrus-edge-worker/dist/ in my install and verified it works end-to-end with pm2 restart cyrus (status endpoint clean, no runtime errors). Happy to turn this into a PR if the approach looks right.