9router/open-sse/executors/codex.js

import { BaseExecutor } from "./base.js";
import { CODEX_DEFAULT_INSTRUCTIONS } from "../config/codexInstructions.js";
import { PROVIDERS } from "../config/constants.js";

/**
 * Codex Executor - handles OpenAI Codex API (Responses API format)
 * Automatically injects default instructions if missing
 */
export class CodexExecutor extends BaseExecutor {
  constructor() {
    super("codex", PROVIDERS.codex);
  }

  /**
   * Transform request before sending - inject default instructions if missing
   */
  transformRequest(model, body, stream, credentials) {
    // If no instructions provided, inject default Codex instructions
    if (!body.instructions || body.instructions.trim() === "") {
      body.instructions = CODEX_DEFAULT_INSTRUCTIONS;
    }

    // Ensure store is false (Codex requirement)
    body.store = false;

    // Extract thinking level from model name suffix
    // e.g., gpt-5.3-codex-high → high, gpt-5.3-codex → medium (default)
    const effortLevels = ['none', 'low', 'medium', 'high', 'xhigh'];
    let modelEffort = null;
    for (const level of effortLevels) {
      if (model.endsWith(`-${level}`)) {
        modelEffort = level;
        // Strip suffix from model name for actual API call
        body.model = body.model.replace(`-${level}`, '');
        break;
      }
    }

    // Priority: explicit reasoning.effort > reasoning_effort param > model suffix > default (medium)
    if (!body.reasoning) {
      const effort = body.reasoning_effort || modelEffort || 'medium';
      body.reasoning = { effort };
    }
    delete body.reasoning_effort;

    // Remove unsupported parameters for Codex API
    delete body.temperature;
    delete body.top_p;
    delete body.frequency_penalty;
    delete body.presence_penalty;
    delete body.logprobs;
    delete body.top_logprobs;
    delete body.n;
    delete body.seed;
    delete body.max_tokens;
    delete body.user; // Cursor sends this but Codex doesn't support it
    delete body.prompt_cache_retention; // Cursor sends this but Codex doesn't support it
    delete body.metadata; // Cursor sends this but Codex doesn't support it
    delete body.stream_options; // Cursor sends this but Codex doesn't support it
    delete body.safety_identifier; // Droid CLI sends this but Codex doesn't support it

    return body;
  }
}