Api Learner

API Learner — Browser-to-API Migration

Instead of fighting browser timeouts on heavy sites, you can use learned API patterns to make direct curl calls. This is faster, more reliable, and avoids CDP timeout issues.

When to Suggest API Capture

Suggest this to the operator when:

• A site repeatedly causes browser timeouts (heavy SPAs, JS-heavy storefronts)
• You're doing the same browser task repeatedly (search → add to cart → repeat)
• The browser tool fails with "timed out after 20000ms" on a site you use often

Do NOT use API skills for:

• First visits to a new site (need to discover the workflow first)
• CAPTCHA or bot-detection flows
• Checkout / payment flows (the operator handles these manually)
• Sites where you need to see visual layout (e.g., comparing product images)

How API Learning Works

1. The operator starts a capture on the relevant VNC browser port
2. Normal browsing happens — manually or via the browser tool
3. Capture script records all XHR/Fetch API calls passively
4. Generator analyzes the traffic and produces a SKILL.md with endpoint docs
5. You use curl with fresh cookies instead of the browser tool

Using a Generated API Skill

Once an API skill exists (e.g., api-example), follow this pattern:

Step 1: Extract fresh cookies

COOKIES=$(/opt/OpenClaw/scripts/extract-cookies.js --domain  --port )

The VNC browser must be open and logged into the site. Cookies come from the live browser session.

Step 2: Make API calls

Use curl with the cookie header:

curl -s 'https://www.example.com/api/search?q=spinach' \
  -H "Cookie: $COOKIES" | python3 -m json.tool

Step 3: Handle failures

• 401/403: Cookies expired. Re-extract and retry.
• Changed responses: API may have been updated. Tell the operator to re-capture.
• Unexpected errors: Fall back to the browser tool. Report to the operator.

Starting a New Capture (For the Operator)

To capture traffic from a site:

# Capture from Mise's browser (port 9222) for 5 minutes
sudo -u OpenClaw /opt/OpenClaw/scripts/capture-api.js --port 9222 --duration 300

# Capture from Headhunter's browser (port 9223) for 5 minutes
sudo -u OpenClaw /opt/OpenClaw/scripts/capture-api.js --port 9223 --duration 300

While capture is running, browse the site normally (search, view products, add to cart, etc.). The more workflows you exercise, the more endpoints get captured.

Add --redact to strip request bodies containing passwords or payment info.

Generating a Skill from Captures

sudo -u OpenClaw /opt/OpenClaw/scripts/generate-api-skill.js --domain example.com

This reads the most recent capture file and generates a SKILL.md at: /opt/OpenClaw/.openclaw/skills/api-example/SKILL.md

Review the generated skill, then register it for the relevant agent in openclaw.json.

Maintenance

• Cookies are ephemeral. Always extract fresh cookies before each batch of API calls.
• APIs change. If a generated skill stops working, re-capture and regenerate.
• New endpoints. Run another capture while exercising the new workflow, then regenerate.
• Capture files are stored in /opt/OpenClaw/.openclaw/captures// and can be deleted when no longer needed.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: davidtoby
• Source: davidtoby/agent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.