Coasty Computer Use API Pricing: Every Endpoint, Every Cent
You want agents that click, scroll, and read screens, not brittle selectors or API-only wrappers. The Coasty computer use API charges per operation, not per month. This post lists every endpoint, every field, and every cent so you can budget your computer use agent.
How it works
The API uses vision models that take screenshots and instructions, then output actions. You loop capture, predict, and act until the status is done. For stateful sessions, you create a session first, then call predict on that ID. Prices are per request or per agent step.
# Predict (vision) - $0.05 per call
# Reads COASTY_API_KEY from env, POST base64 screenshot, instruction, and cua_version
export COASTY_API_KEY="${COASTY_API_KEY}"
# Example using curl (replace screenshot with real base64)
curl -X POST https://coasty.ai/v1/predict \
-H "X-API-Key: $COASTY_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"screenshot": "<base64_image>",
"instruction": "Click the submit button.",
"cua_version": "v3"
}'
# Example using Python (install requests first)
# pip install requests
import os
import base64
import json
import requests
api_key = os.environ.get("COASTY_API_KEY")
url = "https://coasty.ai/v1/predict"
with open("screen.png", "rb") as f:
img_b64 = base64.b64encode(f.read()).decode()
payload = {
"screenshot": img_b64,
"instruction": "Click the submit button.",
"cua_version": "v3"
}
resp = requests.post(url, headers={"X-API-Key": api_key}, json=payload)
print(json.dumps(resp.json(), indent=2))Vision endpoints
- ●POST /v1/predict , $0.05 per call. Requires screenshot (base64), instruction, and cua_version. Returns actions and a status. Loop until status is done.
- ●POST /v1/sessions , $0.10 per session creation. Returns a session ID for stateful trajectory memory.
- ●POST /v1/sessions/{id}/predict , $0.04 per predict call within a session. Uses the session ID and same fields as /v1/predict.
- ●POST /v1/ground , $0.03 per call. Takes screenshot and element description, returns x,y coordinates for click or type.
- ●POST /v1/parse , Free. Turns pyautogui code into structured actions.
Vision operations cost $0.03, 0.05 per call; runs bill $0.05 per agent step.
Task runs (server-driven agents)
POST /v1/runs starts a server-side agent. Required fields: machine_id, task, and cua_version. Optional: instructions, system_prompt, max_steps, deadline_seconds, on_awaiting_human, webhook_url. States: queued, running, awaiting_human, succeeded, failed, cancelled, timed_out. Billed $0.05 per agent step. You can stream events via GET /v1/runs/{id}/events (Server-Sent Events).
Where this beats brittle automation
Traditional automation relies on stable selectors and API wrappers that break when layout changes. The Coasty computer use agent sees the screen, understands context, and acts like a human, handling dynamic UIs without brittle IDs. This is especially valuable for browser automation, desktop GUIs, and workflows that need visual reasoning.
Use the right endpoint for your workflow, budget per step, and integrate the Coasty computer use API into your agent stack. Get your API key and start building at https://coasty.ai/developers.