Get Your Agent to Help

Install the OpenAI API skill so your coding agent knows the current API patterns:

npx skills add jezweb/claude-skills@openai-api

Then ask your agent: "help me build the daily-digest run script using the OpenAI API"

Set Your Key

Get a key from platform.openai.com/api-keys:

export OPENAI_API_KEY="sk-..."
bun run sync

The Pattern

The chat completions endpoint hasn't changed — POST https://api.openai.com/v1/chat/completions with an Authorization: Bearer header:

async function ask(prompt: string): Promise<string> {
  const resp = await fetch("https://api.openai.com/v1/chat/completions", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: `Bearer ${process.env.OPENAI_API_KEY}`,
    },
    body: JSON.stringify({
      model: "gpt-4.1-mini",
      messages: [{ role: "user", content: prompt }],
      max_tokens: 1024,
    }),
  });

  if (!resp.ok) throw new Error(`OpenAI ${resp.status}: ${await resp.text()}`);
  const data = (await resp.json()) as any;
  return data.choices[0].message.content;
}

Current Models (March 2026)

Model	Speed	Cost	Best For
gpt-4.1-mini	Fast	Cheapest	Most scheduled jobs — summaries, classification
gpt-4.1	Mid	Mid	Complex reasoning
gpt-5-mini	Fast	Mid	Latest capabilities, still affordable
gpt-5.3-codex	Mid	Higher	Code-heavy tasks

GPT-4o was retired from ChatGPT in Feb 2026 but remains available in the API. Start with gpt-4.1-mini for scheduled jobs — it's fast and cheap.

Error Handling

LLM APIs fail. Rate limits hit. Always retry with backoff:

async function askWithRetry(prompt: string, retries = 3): Promise<string> {
  for (let i = 0; i < retries; i++) {
    try { return await ask(prompt); }
    catch (err) {
      if (i === retries - 1) throw err;
      await Bun.sleep(1000 * Math.pow(2, i));
    }
  }
  throw new Error("unreachable");
}

API Key at Runtime

The manager injects PATH into the plist but not arbitrary env vars. For the API key to be available when launchd runs your job:

// Read from a dotfile — most durable for scheduled jobs
const key = (await Bun.file(`${Bun.env.HOME}/.config/openai-key`).text()).trim();

Test It

bun run src/cli.ts kick daily-digest
bun run src/cli.ts logs daily-digest

Companion Notes

Branch: OpenAI API

Direct API calls with fetch. You manage the key, you pick the model.

Setup

# Set your API key — the manager injects it into the plist EnvironmentVariables
export OPENAI_API_KEY="sk-..."

The key needs to be available when you run bun run sync. The manager captures process.env.PATH into the plist — but custom env vars need to be in the shell environment at sync time OR set in the schedule file.

Option A: Export before sync

export OPENAI_API_KEY="sk-..."
bun run sync

Option B: Add to schedule file

{"type": "scheduled", "calendar": {"Hour": 8}, "env": {"OPENAI_API_KEY": "sk-..."}}

Note: Option B puts the key in a file. Fine for local-only, but don't commit it.

The Pattern

#!/usr/bin/env bun
const OPENAI_API_KEY = process.env.OPENAI_API_KEY;
if (!OPENAI_API_KEY) {
  console.error("[job] OPENAI_API_KEY not set");
  process.exit(1);
}

async function ask(prompt: string): Promise<string> {
  const resp = await fetch("https://api.openai.com/v1/chat/completions", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: `Bearer ${OPENAI_API_KEY}`,
    },
    body: JSON.stringify({
      model: "gpt-4o-mini",
      messages: [{ role: "user", content: prompt }],
      max_tokens: 1024,
    }),
  });

  if (!resp.ok) {
    const err = await resp.text();
    throw new Error(`OpenAI ${resp.status}: ${err}`);
  }

  const data = (await resp.json()) as any;
  return data.choices[0].message.content;
}

// Use it
const result = await ask("Summarize these notes...");
console.log(result);

Model Selection

Model	Cost	Speed	Best For
gpt-4o-mini	Cheapest	Fast	Most jobs — classification, summaries, short tasks
gpt-4o	Mid	Mid	Complex reasoning, longer outputs
o3-mini	Higher	Slower	Multi-step reasoning, code generation

Start with gpt-4o-mini. It handles 90% of scheduled job tasks.

Error Handling

async function askWithRetry(prompt: string, retries = 3): Promise<string> {
  for (let i = 0; i < retries; i++) {
    try {
      return await ask(prompt);
    } catch (err) {
      if (i === retries - 1) throw err;
      const waitMs = 1000 * Math.pow(2, i); // exponential backoff
      console.warn(`[job] Retry ${i + 1}/${retries} in ${waitMs}ms: ${err}`);
      await Bun.sleep(waitMs);
    }
  }
  throw new Error("unreachable");
}

Rate limits, transient errors, timeouts — scheduled jobs WILL hit these. Retry with backoff.

Verification

# Test the API key
curl -s https://api.openai.com/v1/models \
  -H "Authorization: Bearer $OPENAI_API_KEY" | head -1

# Test through the job
bun run src/cli.ts kick daily-digest
bun run src/cli.ts logs daily-digest