LINE OA B2C — multiple Official Accounts with credit metering

DuduCloud can host several customers’ LINE Official Accounts on one gateway. Each OA binds to its own agent and carries a credit balance; the customer’s end-users chat with that AI customer-service agent, and each reply burns credit.

Configure multiple OAs

config.toml:

[[channels.line.accounts]]
name              = "acme-support"      # label + credit namespace
channel_token_enc = "…"                 # AES-256-GCM (or channel_token plain)
channel_secret_enc = "…"
agent_id          = "acme-agent"
credit_rate       = 2.0                 # points per 1K output tokens; 0 = off

[[channels.line.accounts]]
name              = "beta-shop"
channel_token_enc = "…"
channel_secret_enc = "…"
agent_id          = "beta-agent"
credit_rate       = 1.5

The old single-OA layout (top-level channel_token / channel_secret) still works — it resolves to one account named default. So existing deployments need no change.

Credit management (operator)

Points are granted by the operator; billing settlement (topping up with money via PayUni) is a separate, operator-gated flow.

duduclaw credit grant acme-support U1234567890 500 --reason "monthly plan"
duduclaw credit balance acme-support U1234567890
duduclaw credit history acme-support U1234567890

Metering: each reply costs ceil(output_tokens / 1000 * credit_rate) points. When a user’s balance hits zero and metering is on (credit_rate > 0), the reply is refused before any LLM call (fail-closed) and the user gets a top-up notice. A credit_rate of 0 disables metering for that OA.

Status

The config model, credit ledger, and operator CLI are in place and unit-tested. Wiring the shared /webhook/line endpoint to route by the LINE destination field (per-account signature verify, fail-closed on mismatch) and to gate + deduct on each reply is the remaining integration step; until then a single OA works through the legacy path.