Credits & Billing

Credit model

a21e uses a simple credit system: 1 credit = 1 enhancement (one prompt compilation and execution). Your balance is split into two buckets:

Type	Source	Behavior
Subscription	Monthly plan	Resets on your renewal date
Add-on	Credit packs, admin grants	Never expires, never resets

Credits are consumed subscription-first. Add-on credits are only used once subscription credits are exhausted.

Checking your balance

curl https://api.a21e.com/v1/credits/balance \
  -H "Authorization: Bearer YOUR_API_KEY"

{
  "balance": 550,
  "plan": "pro",
  "mode": "managed"
}

The balance field is your total available credits (subscription + add-on). mode indicates whether you’re on managed (a21e-hosted LLM) or BYOK (your own provider key).

Managed vs. BYOK

	Managed	BYOK
Credit cost	1 credit per enhancement	1 credit per enhancement
LLM cost	Included in credit	Billed by your provider
Setup	Nothing extra	Add provider key in settings

Credits are always required — they cover prompt engineering, context assembly, and orchestration. In BYOK mode, your provider handles the LLM inference cost separately. See BYOK guide for setup instructions.

Usage tracking

Summary

Get a high-level overview of your usage over a time period:

curl "https://api.a21e.com/v1/usage/summary?days=30" \
  -H "Authorization: Bearer YOUR_API_KEY"

Daily breakdown

curl "https://api.a21e.com/v1/usage/by-day?days=30" \
  -H "Authorization: Bearer YOUR_API_KEY"

Run history

List individual runs with pagination:

curl "https://api.a21e.com/v1/usage/runs?days=30&limit=20&offset=0" \
  -H "Authorization: Bearer YOUR_API_KEY"

Each run includes the prompt title, credits used, model, provider, status, and duration.

CSV export

Export your run history as a CSV file for accounting or analysis:

curl "https://api.a21e.com/v1/usage/runs/export?days=30" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -o runs.csv

Credit ledger

The ledger provides a full audit trail of every credit transaction.

List transactions

curl "https://api.a21e.com/v1/credits/ledger?limit=50&offset=0" \
  -H "Authorization: Bearer YOUR_API_KEY"

Each entry includes a entry_type field:

Entry type	Meaning
`debit`	Credit consumed by an enhancement
`refund`	Credits returned (e.g. failed execution)
`grant`	Credits added by admin or credit pack
`pinned_hit`	Prompt pinning cache hit (no credit charged)
`dedup_hit`	Deduplication cache hit (no credit charged)

Period summary

Get aggregated credit activity over a time window (up to 90 days):

curl "https://api.a21e.com/v1/credits/ledger/summary?days=30" \
  -H "Authorization: Bearer YOUR_API_KEY"

{
  "total_debits": 142,
  "total_refunds": 3,
  "total_grants": 0,
  "cache_hits": 28,
  "net_change": -139,
  "period_days": 30,
  "since": "2026-02-06T00:00:00.000Z"
}

Insufficient credits

When your balance reaches zero, API requests return a 402 error:

{
  "error": "INSUFFICIENT_CREDITS",
  "message": "Your credit balance is 0. Purchase additional credits or upgrade your plan.",
  "balance": 0
}

This applies to both managed and BYOK modes — credits are always required for prompt engineering.

Organization credits

Organizations have a separate credit pool shared across all members:

Org admins can purchase credits and set per-member spending limits
Member usage is tracked individually within the org pool
When a member’s personal credits are exhausted, org credits are used (if allowed by policy)

See Organizations for more on team billing.

Getting Started

Guides

Account

Legal

Credits & Billing

Credit model

Checking your balance

Managed vs. BYOK

Usage tracking

Summary

Daily breakdown

Run history

CSV export

Credit ledger

List transactions

Period summary

Insufficient credits

Organization credits

​Credit model

​Checking your balance

​Managed vs. BYOK

​Usage tracking

​Summary

​Daily breakdown

​Run history

​CSV export

​Credit ledger

​List transactions

​Period summary

​Insufficient credits

​Organization credits

Credit model

Checking your balance

Managed vs. BYOK

Usage tracking

Summary

Daily breakdown

Run history

CSV export

Credit ledger

List transactions

Period summary

Insufficient credits

Organization credits