platform/src/servers/api/chat/list-models.ts

import type { ModelInfo } from './types';
import { homedir } from 'os';
import { join } from 'path';

// The Claude harness runs the `claude` CLI, so its tiers are a fixed set.
const CLAUDE_CODE_MODELS: ModelInfo[] = [
  { id: 'claude-code/opus', name: 'opus', provider: 'claude-code', contextWindow: 200000, maxTokens: 16000, reasoning: true, images: true },
  { id: 'claude-code/sonnet', name: 'sonnet', provider: 'claude-code', contextWindow: 200000, maxTokens: 16000, reasoning: true, images: true },
  { id: 'claude-code/haiku', name: 'haiku', provider: 'claude-code', contextWindow: 200000, maxTokens: 8192, reasoning: false, images: true },
];

const OPENCODE_BIN = process.env.OPENCODE_BIN || join(homedir(), '.opencode', 'bin', 'opencode');

// Curated OpenCode models to surface in the picker (the full `opencode models` catalog is ~58 entries).
const OPENCODE_ALLOWLIST = new Set(['opencode/big-pickle', 'opencode/claude-haiku-4-5']);

// Cache the OpenCode catalog; it's stable for a session and `opencode models` costs a subprocess.
let openCodeCache: ModelInfo[] | null = null;

export function invalidateModelCache(): void {
  openCodeCache = null;
}

// Enumerate OpenCode models via `opencode models` (ids are `providerID/modelID`, e.g.
// `opencode/claude-opus-4-8`). Metadata (context/tokens/modalities) is left at neutral defaults for
// now — it can be enriched later from a serve's GET /config/providers.
async function listOpenCodeModels(): Promise<ModelInfo[]> {
  if (openCodeCache) return openCodeCache;
  try {
    const proc = Bun.spawn([OPENCODE_BIN, 'models'], { stdout: 'pipe', stderr: 'ignore' });
    const out = await new Response(proc.stdout).text();
    await proc.exited;

    const models: ModelInfo[] = out
      // eslint-disable-next-line no-control-regex
      .replace(/\x1b\[[0-9;]*m/g, '')
      .split('\n')
      .map((line) => line.trim())
      .filter((line) => OPENCODE_ALLOWLIST.has(line))
      .map((full) => {
        const slash = full.indexOf('/');
        return {
          id: full,
          name: full.slice(slash + 1),
          provider: full.slice(0, slash),
          contextWindow: 200000,
          maxTokens: 8192,
          reasoning: false,
          images: true,
        } satisfies ModelInfo;
      });

    openCodeCache = models;
    return models;
  } catch {
    return [];
  }
}

export async function listChatModels(): Promise<ModelInfo[]> {
  const openCode = await listOpenCodeModels();
  return [...CLAUDE_CODE_MODELS, ...openCode];
}