Send a real fax via FaxDrop.

USE WHEN: user needs to fax a document (PDF, DOCX, JPEG, PNG ≤10MB) to a fax number — medical records, legal forms, government submissions, recipients who only accept fax.

DO NOT USE: for digital delivery (email, sftp), for files outside the outbox, for non-fax numbers — the 3-layer phone gate (TYPE → COUNTRY → per-number policy) rejects mobile/landline/premium.

SIDE EFFECTS: charges FaxDrop balance (or consumes free credits + adds branded cover on free tier), creates an audit log entry, allocates a fax ID server-side. ALWAYS confirm recipient + file + cover with the user before calling.

FILE LOCATION: document must live inside the outbox (default ~/FaxOutbox/, override via FAXDROP_MCP_WORK_DIR). Files outside are rejected — ask the user to copy in first.

RETURNS: { faxId, status: "queued", ... } — poll with faxdrop_get_fax_status.

Add a fax number to the per-recipient whitelist (paired.json).

USE WHEN: server runs with FAXDROP_MCP_NUMBER_GATE=pairing and the user wants to pre-approve a recurring recipient (clinic, lawyer, supplier) so future faxdrop_send_fax calls skip the per-number confirmation step.

DO NOT USE: when gate mode is open (no whitelist needed) or closed (whitelist edited out-of-band only — pairing rejected). For one-off faxes, skip pairing and call faxdrop_send_fax directly.

SIDE EFFECTS: writes to ~/.faxdrop-mcp/paired.json (or $FAXDROP_MCP_STATE_DIR/paired.json). Persistent across runs. ALWAYS confirm with the user — paired numbers can be faxed without further per-number approval.

VALIDATION: TYPE + COUNTRY checks still apply (no bypass). Mobile/landline/premium numbers are rejected even at pairing time.

RETURNS: { paired, country, type }.

Check the delivery status of a previously sent fax.

USE WHEN: polling for the outcome of a fax sent via faxdrop_send_fax. Status values: queued | sending | delivered | failed | partial.

DO NOT USE: for faxes sent outside this MCP (no provenance — server returns 404). Once status is delivered, failed, or partial, STOP polling — these are terminal.

SIDE EFFECTS: each non-cached call hits the FaxDrop API and counts toward its per-key rate limits (no monetary cost). Terminal results are cached process-wide.

POLLING STRATEGY: every ~5s for the first 2 min, then every ~30s up to 10 min. Most US faxes complete in <90s.

RETURNS: provider status object + optional _cached: true flag.