Agent Runtimes

CORAL works with any coding agent that can run as a subprocess. Pick the runtime in task.yaml via agents.runtime. Claude Code is the default and needs no special config beyond an Anthropic API key. The other runtimes are documented below.

OpenCode

OpenCode reads permissions and provider config from an opencode.json file. Place it in your task's seed/ directory so it gets copied into each agent's worktree.

Example (from examples/circle_packing/seed/opencode.json):

{
  "$schema": "https://opencode.ai/config.json",
  "permission": {
    "external_directory": "allow",
    "question": "deny",
    "doom_loop": "allow",
    "bash": "allow",
    "edit": "allow",
    "read": "allow",
    "write": "allow",
    "webfetch": "deny",
    "websearch": "deny",
    "codesearch": "allow",
    "lsp": "allow",
    "skill": "allow"
  },
  "provider": {
    "claude": {
      "npm": "@ai-sdk/anthropic",
      "name": "claude",
      "options": {
        "baseURL": "http://localhost:4000/v1",
        "apiKey": "xxx"
      },
      "models": {
        "claude-opus-4-6": {
          "name": "claude-opus-4-6"
        }
      }
    }
  }
}

Key points:

• Set all permissions to "allow" except question, webfetch, websearch (set those to "deny") so the agent runs autonomously without interactive prompts.
• The provider section configures which model to use. When using the gateway, point baseURL at http://localhost:<gateway_port>/v1 and set apiKey to any placeholder value — the gateway handles authentication.
• Place opencode.json in your seed directory so it gets copied into each agent's worktree.

Task config:

agents:
  runtime: opencode
  model: claude/claude-opus-4-6  # must match a model defined in opencode.json

Cursor Agent

Install Cursor Agent and authenticate once:

curl -fsSL https://cursor.com/install | bash
cursor-agent login

Point your task at it:

agents:
  runtime: cursor          # alias for cursor_agent; "cursor-agent" also works
  model: auto              # or any model id supported by your Cursor plan

CORAL spawns each agent as cursor-agent --print --output-format stream-json --force --workspace <wt> [--model] [--mode] [--resume] <prompt>. The --force flag is always passed (cursor-agent requires it for write tools in --print mode). The full task brief is written to AGENTS.md at the worktree root, and CORAL also drops a .cursor/rules/coral.mdc always-apply rule with short guardrails (use coral eval, don't touch .coral/private/, share via .cursor/notes/ and .cursor/skills/) so they survive context pressure.

Optional runtime_options:

agents:
  runtime: cursor
  runtime_options:
    command: /usr/local/bin/cursor-agent  # override binary path
    mode: plan                            # --mode plan|ask
    stream_partial_output: true           # --stream-partial-output

Note: Cursor Agent uses its own auth and does not route through the LiteLLM gateway. Login state lives in your Cursor account, not in CORAL config.

Kiro

Install Kiro (kiro-cli) and authenticate via Kiro's setup. Then:

agents:
  runtime: kiro
  model: auto              # or any Kiro-supported model

CORAL spawns each agent as kiro-cli chat <prompt> --no-interactive -a (the -a flag trusts all tools). Instructions are read from KIRO.md at the worktree root. Kiro does not currently expose a session id we can resume from, so restarted agents start fresh — they still see all prior attempts and notes via the shared .kiro/ directory.

Like Cursor, Kiro uses its own auth and does not route through the LiteLLM gateway.