docs: map custom_instructions to --append-system-prompt (#1480) (#1484)

* docs: map custom_instructions to --append-system-prompt (#1480)

The v1 migration guide mapped the v0 `custom_instructions` input to
`claude_args: --system-prompt`, but these have different semantics:
`custom_instructions` *appended* to Claude Code's default system prompt,
while `--system-prompt` *replaces* it entirely. Users who followed the
guide silently lost the whole built-in system prompt (tool-usage guidance,
sub-agent conventions, etc.), keeping only their few custom lines.

Fixes #1480:
- Map `custom_instructions` -> `--append-system-prompt` (matches v0 append
  semantics) in the deprecated-inputs table, the migration example, and the
  checklist.
- Correct the claude_args options table: `--system-prompt` replaces the
  entire prompt; add an `--append-system-prompt` row for append behavior.

Docs-only; no code changes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* docs: fix remaining custom_instructions migration references (#1480)

Update usage.md, faq.md, and configuration.md to map custom_instructions
to --append-system-prompt, matching the migration-guide fix. The
override_prompt row is left unchanged since replacement semantics may be
intended there.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
farmer
2026-07-15 20:35:32 -07:00
committed by GitHub
co-authored by Claude Fable 5
parent a1c0599a9c
commit 2988cbe14a
4 changed files with 39 additions and 38 deletions
+24 -23
View File
@@ -14,19 +14,19 @@ This guide helps you migrate from Claude Code Action v0.x to v1.0. The new versi
The following inputs have been deprecated and replaced:
| Deprecated Input | Replacement | Notes |
| --------------------- | ------------------------------------ | --------------------------------------------- |
| `mode` | Auto-detected | Action automatically chooses based on context |
| `direct_prompt` | `prompt` | Direct drop-in replacement |
| `override_prompt` | `prompt` | Use GitHub context variables instead |
| `custom_instructions` | `claude_args: --system-prompt` | Move to CLI arguments |
| `max_turns` | `claude_args: --max-turns` | Use CLI format |
| `model` | `claude_args: --model` | Specify via CLI |
| `allowed_tools` | `claude_args: --allowedTools` | Use CLI format |
| `disallowed_tools` | `claude_args: --disallowedTools` | Use CLI format |
| `claude_env` | `settings` with env object | Use settings JSON |
| `mcp_config` | `claude_args: --mcp-config` | Pass MCP config via CLI arguments |
| `timeout_minutes` | Use GitHub Actions `timeout-minutes` | Configure at job level instead of input level |
| Deprecated Input | Replacement | Notes |
| --------------------- | ------------------------------------- | ----------------------------------------------------------------------------------- |
| `mode` | Auto-detected | Action automatically chooses based on context |
| `direct_prompt` | `prompt` | Direct drop-in replacement |
| `override_prompt` | `prompt` | Use GitHub context variables instead |
| `custom_instructions` | `claude_args: --append-system-prompt` | Appends to the default prompt (v0 behavior); `--system-prompt` replaces it entirely |
| `max_turns` | `claude_args: --max-turns` | Use CLI format |
| `model` | `claude_args: --model` | Specify via CLI |
| `allowed_tools` | `claude_args: --allowedTools` | Use CLI format |
| `disallowed_tools` | `claude_args: --disallowedTools` | Use CLI format |
| `claude_env` | `settings` with env object | Use settings JSON |
| `mcp_config` | `claude_args: --mcp-config` | Pass MCP config via CLI arguments |
| `timeout_minutes` | Use GitHub Actions `timeout-minutes` | Configure at job level instead of input level |
## Migration Examples
@@ -52,7 +52,7 @@ The following inputs have been deprecated and replaced:
anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
claude_args: |
--max-turns 10
--system-prompt "Follow our coding standards"
--append-system-prompt "Follow our coding standards"
--allowedTools Edit,Read,Write
```
@@ -255,14 +255,15 @@ claude_args: |
### Common claude_args Options
| Option | Description | Example |
| ------------------- | ------------------------ | -------------------------------------- |
| `--max-turns` | Limit conversation turns | `--max-turns 10` |
| `--model` | Specify Claude model | `--model claude-4-0-sonnet-20250805` |
| `--allowedTools` | Enable specific tools | `--allowedTools Edit,Read,Write` |
| `--disallowedTools` | Disable specific tools | `--disallowedTools WebSearch` |
| `--system-prompt` | Add system instructions | `--system-prompt "Focus on security"` |
| `--mcp-config` | Add MCP server config | `--mcp-config '{"mcpServers": {...}}'` |
| Option | Description | Example |
| ------------------------ | ------------------------------------------------------------------------- | ------------------------------------------------------ |
| `--max-turns` | Limit conversation turns | `--max-turns 10` |
| `--model` | Specify Claude model | `--model claude-4-0-sonnet-20250805` |
| `--allowedTools` | Enable specific tools | `--allowedTools Edit,Read,Write` |
| `--disallowedTools` | Disable specific tools | `--disallowedTools WebSearch` |
| `--system-prompt` | Replace the entire default system prompt | `--system-prompt "Focus on security"` |
| `--append-system-prompt` | Append to the default system prompt (keeps Claude Code's built-in prompt) | `--append-system-prompt "Follow our coding standards"` |
| `--mcp-config` | Add MCP server config | `--mcp-config '{"mcpServers": {...}}'` |
## Provider-Specific Updates
@@ -330,7 +331,7 @@ You can also pass MCP configuration from a file:
- [ ] Remove `mode` input (auto-detected now)
- [ ] Replace `direct_prompt` with `prompt`
- [ ] Replace `override_prompt` with `prompt` using GitHub context
- [ ] Move `custom_instructions` to `claude_args` with `--system-prompt`
- [ ] Move `custom_instructions` to `claude_args` with `--append-system-prompt`
- [ ] Convert `max_turns` to `claude_args` with `--max-turns`
- [ ] Convert `model` to `claude_args` with `--model`
- [ ] Convert `allowed_tools` to `claude_args` with `--allowedTools`