HTTP MCP server at https://app.ohfax.com/mcp.
claude mcp add --transport http ohfax https://app.ohfax.com/mcp
Add to .cursor/mcp.json or Settings → MCP:
{
"mcpServers": {
"ohfax": {
"url": "https://app.ohfax.com/mcp"
}
}
}
codex mcp add ohfax --url https://app.ohfax.com/mcp
For manual configuration, set url = "https://app.ohfax.com/mcp" under [mcp_servers.ohfax] in ~/.codex/config.toml. The remote URL uses streamable HTTP.
Add to ~/.config/muse/settings.json:
{
"schema_version": 1,
"mcp_servers": {
"ohfax": {
"transport": "streamable_http",
"url": "https://app.ohfax.com/mcp",
"mode": "optional"
}
}
}
Remote URL: https://app.ohfax.com/mcp (streamable HTTP). No API key for the MPP path; use an MPP-capable payer such as mppx or an agent wallet.
Optional: after Google sign-in, Account also shows the live MCP URL and install command. MCP payment needs no Oh Fax account, but requires an MPP-capable payer such as mppx or an agent wallet.
quote_fax — Price a fax before committing. Validates destination and document, returns exact total and a payment link. Free; sends nothing. Always call before send_fax. Inputs: to, and either document_url or document_base64.send_fax — Returns authorization instructions for a previously quoted fax. This tool itself does not charge; paying the returned link transmits the document. Input: quote_id from quote_fax.get_fax_status — Poll delivery state for a fax id.get_fax_receipt — Fetch the delivery receipt once the fax is final.
Agents do not need an Oh Fax account or API key; they need an MPP-capable payer (mppx or an agent wallet). After quote_fax, pay by POSTing to
https://app.ohfax.com/pay?quote_id=… — unpaid requests get HTTP 402 (Machine Payments Protocol).
Discovery: GET https://app.ohfax.com/openapi.json. Binding amount is always the 402 challenge (not the OpenAPI floor).
Developers who prefer a prepaid balance use Account + REST/CLI instead.
Agents pay via MPP — no Oh Fax account required; an MPP-capable payer (mppx or an agent wallet) is required.