Use the REPL

Get productive with chimera code, the interactive coding session that gives you a conversational agent with full tool access.

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Prerequisites

pip install chimera-run[anthropic]
export ANTHROPIC_API_KEY="sk-ant-..."

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Starting the REPL

chimera code --model claude-sonnet-4 --workdir ./my-project

You will see a startup banner like:

chimera code v0.1.0 | model: claude-sonnet-4 | /help for commands

The --workdir flag sets the working directory for all file operations. Omit it to default to the current directory. --max-steps 80 raises the per-turn tool-call limit (default 50).

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Asking Questions

Type naturally at the > prompt. The agent has access to all 20 built-in tools (read, write, edit, bash, search, git, think, todo, etc.) and will use them automatically.

> Find all TODO comments in the codebase and list them by file

> Refactor the User class to use dataclasses

> Run the test suite and fix any failures

After each turn, the REPL prints cost and step count:

  [cost: $0.0312 | steps: 4]

Press Ctrl-C to interrupt a long-running turn. Press Ctrl-D or type /exit to quit.

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Slash Commands

All commands start with / and support tab completion.

Information

Command	Description
/help	List all available commands.
/model	Show the current model name.
/cost	Show total cost, per-model breakdown, and remaining budget.
/context	Show message count and estimated token usage.
/history	Show the last 10 messages (role + first 80 chars).
/tools	List all loaded tools with descriptions.

Session Control

Command	Description
/clear	Clear the entire conversation context and start fresh.
/compact	Compress context when the token window fills up.
/debug	Toggle debug mode on/off (shows raw tool calls).
/init	Re-initialize the agent with updated project context.
/yolo	Toggle YOLO mode (auto-approve all tool calls).
/exit	Quit the REPL and print total session cost.

Persistence

Command	Description
/session save my-feature	Save the current session with an optional name.
/session list	Show session management options.
/session fork	Fork the session (branch the conversation).

Branching (SessionTree)

Command	Description
/tree	Display the full session branch tree.
/branch [name]	Create a new named branch from the current point.
/switch <name>	Switch to an existing branch.

Checkpoints

Command	Description
/checkpoint save before-refactor	Create a named checkpoint.
/checkpoint list	List all checkpoints with IDs and timestamps.
/checkpoint restore before-refactor	Roll back to a named checkpoint.
/checkpoint undo	Undo to the most recent checkpoint.

Audit and Agents

Command	Description
/audit	Show a summary of tool execution decisions (allowed/denied counts).
/audit clear	Clear the audit log.
/agent list	List available agent presets (build, review, explore, etc.).

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Tips

• Watch your costs. Run /cost periodically. The breakdown shows spending per model so you can spot expensive turns.
• Compact before you hit limits. When /context reports high token counts, run /compact to compress the history and free up context window space.
• Save before risky changes. Use /checkpoint save before asking the agent to do large refactors. Restore if things go sideways.
• Use sessions across days. /session save my-feature persists the full conversation. Resume it tomorrow without losing context.
• History is saved automatically. Readline history is written to ~/.chimera/history (up to 1000 entries) and restored on next launch.

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Next Steps

• Add Security Policies — control what the agent is allowed to do.
• Build a Coding Agent — use the same components programmatically.