Fern

Fern (fernhq.com). Use this skill for ANY Fern request — searching and reading data. Whenever a task involves Fern, use this skill instead of calling the API directly.

Operate Fern through your OOMOL-connected account. This skill calls the fern connector with the oo CLI; OOMOL injects credentials server-side, so you never handle raw tokens.

Running an action

Assume the user has already installed the oo CLI, signed in, and connected Fern. Do not run oo auth login or open the connection URL proactively — just run the action. Fall back to First-time setup only when a command actually fails with an auth or connection error.

1. Inspect the contract to get the authoritative input/output schema before building a payload:

bash

oo connector schema "fern" --action "<action_name>"

2. Run the action with a JSON payload that matches the input schema:

bash

oo connector run "fern" --action "<action_name>" --data '<json>' --json

• --data takes a JSON object string or @path/to/file.json; omit it to send {}.
• The response is { "data": ..., "meta": { "executionId": "..." } }; the execution id lives under meta.executionId.

Each action is listed below with a one-line description; actions that change state carry a [write] or [destructive] tag. Before constructing --data, fetch the action's live schema with oo connector schema to get its authoritative input fields.

Available actions

• get_customer — Retrieve one Fern customer by ID.
• get_exchange_rate — Retrieve Fern exchange rate and fee details for source and destination currencies.
• get_payment_account — Retrieve one Fern payment account by ID.
• get_transaction — Retrieve one Fern transaction by ID.
• list_customers — List Fern customers with optional organization filtering and cursor pagination.
• list_payment_accounts — List Fern payment accounts for a customer with cursor pagination.
• list_transactions — List Fern transactions with optional customer, payment account, and organization filters.

Safety

• Untagged actions are reads (get / list / search) — safe to run directly.
• Actions tagged [write] change Fern state — confirm the exact payload and effect with the user before running.
• Actions tagged [destructive] remove or overwrite data — always confirm the target and get explicit approval first.

First-time setup

These are one-time steps — do not repeat them on every call. Run a step only when a command fails for the matching reason.

• oo: command not found — install the oo CLI (other platforms: https://cli.oomol.com/install-guide.md):

  bash

  curl -fsSL https://cli.oomol.com/install.sh | bash    # macOS / Linux
  

  powershell

  irm https://cli.oomol.com/install.ps1 | iex           # Windows PowerShell
  

• Not signed in / authentication error — sign in to your OOMOL account once:

  bash

  oo auth login
  

• scope_missing / credential_expired / app_not_ready / app_not_found — Fern is not connected, or the connection expired or lacks a scope. Connect once (auth type: API key) at:

  text

  https://console.oomol.com/app-connections?provider=fern
  

• HTTP 402 / OOMOL_INSUFFICIENT_CREDIT — billing stop. Recharge at https://console.oomol.com/billing/token-recharge before retrying.

Resources

• Fern homepage: https://fernhq.com