JuliusBrussee/caveman · error · Error

cave_claude_tool_contract_unsupported:${unsupportedTool.name

Error message

cave_claude_tool_contract_unsupported:${unsupportedTool.name}

What it means

Error "cave_claude_tool_contract_unsupported:${unsupportedTool.name}" thrown in JuliusBrussee/caveman.

Source

Thrown at packages/agent/src/claude-runtime.ts:103

  if (options.lockedBuild !== undefined && options.candidatePlan !== undefined) {
    throw new Error("cave_execution_authorization_ambiguous");
  }
  if (options.candidatePlan !== undefined) {
    throw new Error("cave_claude_candidate_execution_unavailable");
  }
  if (options.lockedBuild !== undefined) {
    throw new Error("cave_claude_locked_execution_unavailable");
  }
  if (definition.memory !== undefined) {
    throw new Error("cave_claude_memory_bridge_unavailable");
  }
  if (definition.tools.some((item) => item.runtime?.kind === "subagent")) {
    throw new Error("cave_claude_subagent_bridge_unavailable");
  }
  const unsupportedTool = definition.tools.find((item) =>
    item.effect !== "read" || item.result !== "inline");
  if (unsupportedTool !== undefined) {
    throw new Error(`cave_claude_tool_contract_unsupported:${unsupportedTool.name}`);
  }
  if (options.maxTurns !== undefined &&
      (!Number.isSafeInteger(options.maxTurns) || options.maxTurns <= 0 || options.maxTurns > 1_000)) {
    throw new Error("cave_claude_max_turns_invalid");
  }
  if (options.maxBudgetUsd !== undefined &&
      (!Number.isFinite(options.maxBudgetUsd) || options.maxBudgetUsd <= 0)) {
    throw new Error("cave_claude_max_budget_invalid");
  }
  const rootDir = resolve(options.rootDir ?? process.cwd());
  const lowered = await lowerAgentContext(definition, { rootDir, input });
  const bill = contextBill(lowered.ir);
  const selected = resolveClaudeModel(definition, rootDir);
  const reasoningOptions = claudeReasoningOptions(
    selected,
    definition.reasoning,
    definition.output?.maxTokens,
  );

View on GitHub (pinned to 27d5a3981a)

Solutions

1. The named tool uses a contract the Claude runtime does not support; change the tool contract or drop the tool.

When it happens

Trigger: Thrown at packages/agent/src/claude-runtime.ts:103 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of JuliusBrussee/caveman@27d5a3981a (2026-08-15). Data as JSON: /api/errors/7b45b3ebba4236f9. Report an issue: GitHub.