Agentline.cloud

Data & APIs

Make phone calls, send SMS, provision numbers, manage agents, and track billing through the AgentLine telephony API. Use when the user asks to call someone, send a text, check transcripts, manage phone agents, buy numbers, or check account balance.

Install

openclaw skills install agentline-telephone

AgentLine — AI Telephony Skill

Give your AI agent a real phone number, voice calls, and SMS — no servers, no webhooks, no infrastructure.

First-Time Setup

You need a valid API key to use AgentLine:

AGENTLINE_API_KEY: Your API key (starts with sk_live_) is required.
- If you do NOT have this key, stop and ask the human to sign up or log in at https://agentline.cloud to get their API key. Do NOT proceed without it.
AGENTLINE_AGENT_ID: Your agent ID (starts with agt_) is optional.
- If you have an AGENTLINE_AGENT_ID, use it.
- If you do NOT have an AGENTLINE_AGENT_ID but you have the API key, you can automatically create a new agent by calling POST /v1/agents and then provision a phone number by calling POST /v1/numbers!

Authentication

Every request needs this header:

Authorization: Bearer $AGENTLINE_API_KEY
Content-Type: application/json

Base URL: https://agentphone-production.up.railway.app

How Calls Work (Hosted Mode)

AgentLine runs in Hosted Mode — the server runs the AI voice conversation for you. You create a call, the AI handles the conversation autonomously, and you retrieve the transcript afterwards.

System Prompts — Two Types

Dynamic prompt — set per outbound call using the system_prompt field in POST /v1/calls. This overrides the default for that specific call only.
Default prompt — stored on the agent via PATCH /v1/agents/{agent_id}. This is the permanent prompt used for all inbound calls and any outbound call where no dynamic prompt is provided.

Make an Outbound Call

curl -X POST $AGENTLINE_URL/v1/calls \
  -H "Authorization: Bearer $AGENTLINE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agent_id": "$AGENTLINE_AGENT_ID",
    "to_number": "+1XXXXXXXXXX",
    "system_prompt": "You are calling to schedule a meeting. Be polite and concise.",
    "initial_greeting": "Hi! I wanted to check about scheduling a meeting."
  }'

Field	Required	Description
`agent_id`	Yes	Your agent ID
`to_number`	Yes	E.164 phone number to call
`system_prompt`	No	Dynamic prompt for this call only (overrides default)
`initial_greeting`	No	What the agent says first when the person picks up

The AI handles the full conversation. Poll GET /v1/calls/<call_id> until status is completed to get the transcript.

If you get 400 "Agent has no active phone number", provision one first (see below).

End a Call

curl -X POST $AGENTLINE_URL/v1/calls/<call_id>/hangup \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Get Call Transcript

curl $AGENTLINE_URL/v1/calls/<call_id>/transcript \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Returns the full conversation transcript as an array of {role, text, timestamp} entries.

List Calls (Call Logs)

# All calls
curl "$AGENTLINE_URL/v1/calls?limit=20" \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

# Filter by status
curl "$AGENTLINE_URL/v1/calls?status=completed&limit=10" \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Returns call history with direction, status, duration, phone numbers, and timestamps.

Get Single Call Details

curl $AGENTLINE_URL/v1/calls/<call_id> \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Send an SMS

curl -X POST $AGENTLINE_URL/v1/messages \
  -H "Authorization: Bearer $AGENTLINE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agent_id": "$AGENTLINE_AGENT_ID",
    "to_number": "+1XXXXXXXXXX",
    "body": "Hey! Your appointment is confirmed for Tuesday 3pm."
  }'

Pass "media_url": "https://..." to send an MMS with an image.

List Messages

curl "$AGENTLINE_URL/v1/messages?limit=20" \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Set the Default System Prompt

The default system prompt is used for all inbound calls and any outbound call where no dynamic prompt is given.

curl -X PATCH $AGENTLINE_URL/v1/agents/$AGENTLINE_AGENT_ID \
  -H "Authorization: Bearer $AGENTLINE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "system_prompt": "You are a friendly customer support agent for Acme Corp. Help callers with orders, returns, and general questions. Keep responses brief and professional.",
    "initial_greeting": "Hello! Thanks for calling Acme Corp. How can I help you today?"
  }'

Field	Description
`system_prompt`	The permanent AI instructions for this agent
`initial_greeting`	What the agent says when answering inbound calls
`name`	Display name for the agent
`model_tier`	`"turbo"`, `"balanced"`, or `"max"`

Get Agent Details

curl $AGENTLINE_URL/v1/agents/$AGENTLINE_AGENT_ID \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

List All Agents

curl $AGENTLINE_URL/v1/agents \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Provision a Phone Number

Each agent needs a phone number to make/receive calls and send SMS. Only US numbers are supported.

curl -X POST $AGENTLINE_URL/v1/numbers \
  -H "Authorization: Bearer $AGENTLINE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agent_id": "$AGENTLINE_AGENT_ID",
    "country": "US",
    "number_type": "local",
    "pattern": "415"
  }'

Field	Required	Description
`agent_id`	Yes	Agent to attach the number to
`country`	Yes	Must be `"US"`
`number_type`	No	`"local"` or `"tollfree"` (default: local)
`pattern`	No	Area code filter (e.g. `"212"` for NYC, `"415"` for SF)

Cost: $2.00 per number. Each agent can only have one active number.

List Phone Numbers

curl $AGENTLINE_URL/v1/numbers \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Release a Phone Number

curl -X DELETE $AGENTLINE_URL/v1/numbers/<number_id> \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Check Balance

curl $AGENTLINE_URL/v1/billing/balance \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Returns current balance, how many call minutes and phone numbers you can afford, and the rate card.

View Expenditure

# Full breakdown (current month)
curl "$AGENTLINE_URL/v1/billing/expenditure?period=current_month" \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

# Call charges only (with per-call detail)
curl "$AGENTLINE_URL/v1/billing/expenditure/calls?limit=10" \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

# Number provisioning charges
curl "$AGENTLINE_URL/v1/billing/expenditure/numbers" \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Period options: current_month, last_month, all_time, or YYYY-MM (e.g. 2026-05).

Verify Balance Deduction After a Call

curl $AGENTLINE_URL/v1/billing/verify/<call_id> \
  -H "Authorization: Bearer $AGENTLINE_API_KEY"

Returns whether the call was charged, the expected vs actual cost, and the balance snapshot. Use this to confirm billing accuracy after each call.

Rates

Item	Cost
Outbound call	$0.10 per minute (billed per second)
Inbound call	$0.10 per minute (billed per second)
Phone number	$2.00 per number (one-time)

Rules

Always use E.164 phone numbers — format: +1XXXXXXXXXX for US numbers.
Always confirm with the user before placing calls — never auto-dial without explicit consent.
If you have AGENTLINE_API_KEY but no AGENTLINE_AGENT_ID: Create a new agent using POST /v1/agents first, then provision a number via POST /v1/numbers to get fully set up automatically.
Use the active $AGENTLINE_AGENT_ID or the one you created by default — only look up other agents if the user asks.
If a call fails with "Agent has no active phone number", provision a number first with POST /v1/numbers.
Keep voice responses short — under 30 words per response. The caller is listening, not reading.
Only US numbers are supported — country must be "US".
If you do not have AGENTLINE_API_KEY, stop and tell the human: "Please sign up or log in at https://agentline.cloud to get your API key, then provide it to me."