skyvern

Skyvern Browser Automation -- CLI Judgment Procedure

Skyvern uses AI to navigate and interact with websites. Every command below is a runnable skyvern <command> invocation.

Step 1: Classify Your Task (ALWAYS do this first)

Classification	Signal	CLI Command	Cost	What Happens
Quick check (yes/no)	"is the user logged in?"	skyvern browser validate	1 LLM + screenshots	Lightweight validation (2 steps max), returns boolean. Cheapest AI option.
Quick inspection	"what does the page show?"	skyvern browser extract	1 LLM + screenshots	Dedicated extraction LLM + schema validation + caching.
Single action (known target)	"click #submit"	skyvern browser click/type	0 LLM	Deterministic Playwright. No AI. Fastest.
Single action (unknown target)	"click the submit button"	skyvern browser act	2-3 LLM, no screenshots	No screenshots in reasoning. Economy a11y tree. For visual targets, use hybrid mode (selector + intent).
Same-page multi-step	"fill the form and submit"	skyvern browser act or primitive chain	2-3 LLM or 0 LLM	Use act when labels are clear. Use click/type/select directly when you know selectors.
Throwaway autonomous trial	"try this once", "see if this works"	skyvern browser run-task	Higher	One-off autonomous agent for exploration. Do not use for recurring or multi-page production automations.
Multi-page or reusable automation	"navigate a multi-page wizard", "set this up", "automate this weekly"	skyvern workflow create + run	N LLM + screenshots	Build a workflow with one block per step. Each block gets visual reasoning, verification, and reusable run history.

MCP note: if you are using the Skyvern MCP instead of the CLI, prefer observe + execute for same-page multi-step UI work on stdio; refs persist across calls until the next observe, navigation, or page/document context change. On hosted stateless HTTP, prefer selector or intent params; prior-call refs do not resolve, and one execute batch can use refs only when predictable before the call, never adaptively from an inline observe. The CLI does not expose that pair directly.

Step 2: Apply These Decision Rules

1. If the prompt includes a selector, id, XPath, or exact field target, use browser primitives -- not act.
2. If you only need a yes/no answer, use validate -- not extract or act.
3. If the work stays on one page and labels are clear, use act or a primitive chain.
4. If the user says try this once, see if this works, or clearly wants a one-off exploratory trial, use run-task.
5. If the task spans multiple pages and is meant to be reusable, scheduled, repeatable, or explicitly set up as automation, use workflow create.
6. Never type passwords. Always use stored credentials with skyvern browser login.

Step 3: Create a Session

Every browser command needs a session. Create one first:

# Cloud session (default -- works for public URLs)
skyvern browser session create --timeout 30

# Local session (for localhost URLs or self-hosted mode)
skyvern browser session create --local --timeout 30

# Connect to existing browser via CDP
skyvern browser session connect --cdp "ws://localhost:9222"

Session state persists between commands. After session create, subsequent commands auto-attach. Override with --session pbs_.... Close when done: skyvern browser session close.

Step 4: Execute by Classification

Quick check (yes/no)

skyvern browser validate --prompt "Is the user logged in? Look for a dashboard or avatar."

Returns true/false. Cheapest AI option -- prefer over extract or act for boolean checks.

Quick inspection

skyvern browser extract \
  --prompt "Extract all product names and prices" \
  --schema '{"type":"object","properties":{"items":{"type":"array","items":{"type":"object","properties":{"name":{"type":"string"},"price":{"type":"string"}}}}}}'

Uses screenshots + dedicated extraction LLM. Better than screenshot+read because Skyvern's LLM interprets the page.

Single action (known target)

skyvern browser click --selector "#submit-btn"
skyvern browser type --text "[email protected]" --selector "#email"
skyvern browser select --value "US" --intent "the country dropdown"

Deterministic. No AI. Three targeting modes:

1. Intent: --intent "the Submit button" (AI finds element)
2. Selector: --selector "#submit-btn" (CSS/XPath, deterministic)
3. Hybrid: both (selector narrows, AI confirms)

Single action (unknown target)

skyvern browser act --prompt "Click the Sign In button"
skyvern browser act --prompt "Close the cookie banner, then click Sign In"

Warning: act has NO screenshots in its LLM reasoning. It uses an economy accessibility tree. Fine for well-labeled elements. For visually complex targets, use MCP observe+execute on stdio (on hosted stateless HTTP prefer selector/intent) or hybrid mode.

Same-page multi-step

skyvern browser act --prompt "Fill the shipping form and click Continue"

Use act when the fields and buttons are clearly labeled and the flow stays on one page. If you need tighter control, break the work into click, type, select, press-key, and wait.

Throwaway autonomous trial

skyvern browser run-task \
  --url "https://example.com" \
  --prompt "Check whether the checkout flow works end to end and extract the confirmation number"

Use run-task to prove feasibility or do one-off exploration. If the task becomes important enough to rerun, debug, or share, convert it to a workflow.

Multi-page or reusable automation — build a workflow with one block per step

skyvern workflow create --definition @checkout-workflow.yaml
skyvern workflow run --id wpid_123 --wait
skyvern workflow status --run-id wr_789

Each navigation block runs with visual reasoning + verification. Split complex flows into multiple blocks (one per page/step). First run uses AI; subsequent runs replay cached scripts.

Repeated/production

skyvern workflow create --definition @workflow.yaml
skyvern workflow run --id wpid_123 --params '{"email":"[email protected]"}'
skyvern workflow status --run-id wr_789

Split into one block per step. Use navigation blocks for actions, extraction for data. First run uses AI; subsequent runs replay a cached script (10-100x faster). Set --run-with agent to force AI mode for debugging.

Step 5: Verify

Always verify after page-changing actions:

skyvern browser screenshot                          # visual check
skyvern browser validate --prompt "Was the form submitted successfully?"  # boolean assertion
skyvern browser evaluate --expression "document.title"                    # JS state check

Step 6: Error Recovery

Problem	Fix
Action clicked wrong element	Add context to prompt. Use hybrid mode (selector + intent).
Extraction returns empty	Wait for content. Relax required fields. Check row count first.
Login passes but next step fails	Ensure same session. Add post-login validate check.
Element not found	Add wait: skyvern browser wait --selector "#el" --state visible
Overloaded prompt	Split into smaller goals -- one intent per command.

Credentials

NEVER type passwords through skyvern browser type or act. Always use stored credentials:

skyvern credentials add --name "my-login" --type password --username "[email protected]"
skyvern credential list                          # find the credential ID
skyvern browser login --url "https://login.example.com" --credential-id cred_123

Types: password, credit_card, secret. Also supports bitwarden, 1password, and azure_vault providers.

Workflow Quick Reference

skyvern workflow create --definition @workflow.yaml   # create
skyvern workflow run --id wpid_123 --wait             # run and wait
skyvern workflow status --run-id wr_789               # check status
skyvern workflow list --search "invoice"              # find workflows
skyvern block schema --type navigation                # discover block types
skyvern block validate --block-json @block.json       # validate before creating

Engine: known path = 1.0 (default). Dynamic planning = 2.0. Split into multiple 1.0 blocks when in doubt. Status lifecycle: created -> queued -> running -> completed | failed | canceled | terminated | timed_out

Common Patterns

Login flow:

skyvern credential list                          # find credential ID
skyvern browser session create
skyvern browser navigate --url "https://login.example.com"
skyvern browser login --url "https://login.example.com" --credential-id cred_123
skyvern browser validate --prompt "Is the user logged in?"
skyvern browser screenshot

Pagination loop:

skyvern browser extract --prompt "Extract all rows"
skyvern browser validate --prompt "Is there a Next button that is not disabled?"
# If true:
skyvern browser act --prompt "Click the Next page button"
# Repeat extraction. Stop when: no next button, duplicate first row, or max page limit.

Debugging:

skyvern browser screenshot                       # visual state
skyvern browser evaluate --expression "document.title"
skyvern browser evaluate --expression "document.querySelectorAll('table tr').length"

Agent Mode

All commands accept --json for structured output. Set SKYVERN_NON_INTERACTIVE=1 to prevent prompts. Use skyvern capabilities --json for full command discovery. See references/agent-mode.md.

Deep-Dive References

Reference	Content
references/prompt-writing.md	Prompt templates and anti-patterns
references/engines.md	When to use tasks vs workflows
references/schemas.md	JSON schema patterns for extraction
references/pagination.md	Pagination strategy and guardrails
references/block-types.md	Workflow block type details with examples
references/parameters.md	Parameter design and variable usage
references/ai-actions.md	AI action patterns and examples
references/precision-actions.md	Intent-only, selector-only, hybrid modes
references/credentials.md	Credential naming, lifecycle, safety
references/sessions.md	Session reuse and freshness decisions
references/common-failures.md	Failure pattern catalog with fixes
references/screenshots.md	Screenshot-led debugging workflow
references/status-lifecycle.md	Run status states and guidance
references/rerun-playbook.md	Rerun procedures and comparison
references/complex-inputs.md	Date pickers, uploads, dropdowns
references/tool-map.md	Complete tool inventory by outcome
references/cli-parity.md	CLI/MCP mapping and agent-aware features
references/quick-start-patterns.md	Quick start examples, common patterns, and workflow templates