Bring Your Own Key (BYOK) - a21e

Overview

BYOK lets you provide your own API keys for LLM providers. a21e handles prompt engineering and execution orchestration; inference calls go directly to your provider account.

Supported providers

Provider	Key prefix	Models available
Anthropic	`sk-ant-`	Claude Sonnet 4, Claude Opus 4
OpenAI	`sk-`	GPT-4o, GPT-4.1
Google	`AIza`	Gemini 2.5 Pro, Gemini 2.5 Flash
xAI	`xai-`	Grok 3

Adding a provider key

Go to Settings > Provider Keys in the dashboard
Click Add provider key
Select the provider and paste your API key
The key is encrypted at rest and never logged

Or via API:

curl -X POST https://api.a21e.com/v1/provider-keys \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "provider": "anthropic",
    "api_key": "sk-ant-..."
  }'

How billing works with BYOK

Mode	a21e credits	LLM cost
Managed (no BYOK key)	1 credit per enhancement (covers prompt engineering + inference)	Included
BYOK (your key)	1 credit per enhancement (covers prompt engineering only)	Billed by provider directly

Credits are still required in BYOK mode — they cover prompt synthesis, technique selection, quality scoring, and memory. The LLM inference cost is the only part that shifts to your provider account.

Key security

Keys are encrypted with AES-256 before storage
Keys are never included in logs, error messages, or API responses
Keys are only decrypted at the moment of an LLM call, in memory
You can rotate or delete keys at any time