Bug Description

maxTurns is never wired through to the SDK in src/entrypoints/run.ts, causing all runs to hit the SDK's default limit of 10 turns regardless of configuration.

Root Cause

src/entrypoints/run.ts line 268 calls runClaude() without passing maxTurns:

const claudeResult: ClaudeRunResult = await runClaude(promptConfig.path, {
  claudeArgs: prepareResult.claudeArgs,
  appendSystemPrompt: process.env.APPEND_SYSTEM_PROMPT,
  model: process.env.ANTHROPIC_MODEL,
  pathToClaudeCodeExecutable: process.env.INPUT_PATH_TO_CLAUDE_CODE_EXECUTABLE,
  showFullOutput: process.env.INPUT_SHOW_FULL_OUTPUT,
  // maxTurns is MISSING
});

The ClaudeOptions type in base-action/src/run-claude.ts supports maxTurns, and parse-sdk-options.ts correctly parses it:

maxTurns: options.maxTurns ? parseInt(options.maxTurns, 10) : undefined,

But since run.ts never provides it, sdkOptions.maxTurns is always undefined, and the SDK defaults to 10.

Notably, the base-action/src/index.ts entrypoint does pass it correctly:

maxTurns: process.env.INPUT_MAX_TURNS,

But the main action uses src/entrypoints/run.ts, not the base-action entrypoint.

Why --max-turns in claude_args doesn't work either

Passing --max-turns 50 via claude_args puts the value into extraArgs["max-turns"], which is passed through to the CLI subprocess. However, the SDK enforces its own turn counter from sdkOptions.maxTurns (which is undefined → 10), so the CLI never gets a chance to process more than 10 turns.

Error

Claude Code returned an error result: Reached maximum number of turns (10)
  at readMessages (/home/runner/work/_actions/anthropics/claude-code-action/v1/node_modules/@anthropic-ai/claude-agent-sdk/sdk.mjs:58:14849)

Suggested Fix

Add maxTurns to the runClaude() call in src/entrypoints/run.ts, and add a max_turns input to action.yml:

action.yml:

max_turns:
  description: "Maximum number of conversation turns for the SDK"
  required: false

src/entrypoints/run.ts:

const claudeResult: ClaudeRunResult = await runClaude(promptConfig.path, {
  claudeArgs: prepareResult.claudeArgs,
  appendSystemPrompt: process.env.APPEND_SYSTEM_PROMPT,
  model: process.env.ANTHROPIC_MODEL,
  maxTurns: process.env.INPUT_MAX_TURNS,  // <-- add this
  pathToClaudeCodeExecutable: process.env.INPUT_PATH_TO_CLAUDE_CODE_EXECUTABLE,
  showFullOutput: process.env.INPUT_SHOW_FULL_OUTPUT,
});

And wire INPUT_MAX_TURNS in the run step env:

INPUT_MAX_TURNS: ${{ inputs.max_turns }}

Same issue likely applies to systemPrompt, allowedTools, disallowedTools, mcpConfig, and fallbackModel — all supported by ClaudeOptions but not passed from run.ts.

Reproduction

1. Create a workflow using anthropics/claude-code-action@v1
2. Set claude_args: "--max-turns 50" or max_turns: 50
3. Trigger the action with a task requiring more than 10 turns
4. Observe: Reached maximum number of turns (10)

Environment

• Action version: anthropics/claude-code-action@v1
• Claude Code version installed by action: 2.1.92