manifest-api

Stop guessing selectors. Manifest tells your agent what's clickable, fillable, and submittable on any page.

Python SDK for the Manifest API — extracts structured action manifests from web pages so AI agents know what they can do, not just what's on screen.

Install

pip install manifest-api

Quickstart

Sync

from manifest_api import ManifestClient

client = ManifestClient(api_key="your-key")  # or set MANIFEST_API_KEY env var
manifest = client.get("https://example.com")

print(manifest.current_page_state)
print(manifest.actions)

# Convenience helpers
action = manifest.action("submit-form")
inputs = manifest.actions_of_type("input")
required = manifest.required_actions

# Cheap structural-change check (no LLM call, never cached)
fp = client.fingerprint("https://example.com")
print(fp.fingerprint)

Async

import asyncio
from manifest_api import AsyncManifestClient

async def main():
    async with AsyncManifestClient(api_key="your-key") as client:
        manifest = await client.get("https://example.com")
        print(manifest.current_page_state)

asyncio.run(main())

LangChain

pip install "manifest-api[langchain]"

from manifest_api.integrations.langchain import create_manifest_tool

tool = create_manifest_tool()  # reads MANIFEST_API_KEY from env
# or: create_manifest_tool(api_key="...")

# use with an agent, e.g.:
from langchain.agents import create_agent
agent = create_agent(model=..., tools=[tool])

create_manifest_tool wraps AsyncManifestClient as a get_manifest(url) StructuredTool — the API key is bound at creation time, so the LLM never sees it.

All methods

# Both ManifestClient and AsyncManifestClient expose:
manifest = client.get("https://example.com")          # POST /manifest → Manifest
fp       = client.fingerprint("https://example.com")  # POST /fingerprint → Fingerprint
health   = client.health()                             # GET  /health → dict
valid    = client.session_valid()                      # GET  /session-status → bool

Manifest helpers

manifest.action("id")              # → Action | None
manifest.actions_of_type("input")  # → list[Action]
manifest.required_actions          # → list[Action]
manifest.blocked_actions([...])    # → list[Action], see "Action dependencies" below
manifest.fingerprint               # → str | None, same hash `fingerprint()` returns

Fingerprint

fingerprint(url) runs the same page-render + extraction pipeline as get(url) but skips the LLM translation step, returning just a stable hash of the page's interactive surface (Fingerprint.fingerprint). Useful for cheaply polling whether a page's action surface has changed since your last get() call, without paying for another manifest generation. Every Manifest also carries this same hash on manifest.fingerprint, so you can compare it against a later fingerprint() call directly.

fp = client.fingerprint("https://example.com")
print(fp.url, fp.fingerprint)

Action dependencies

Some actions are disabled until others are completed (e.g. a submit button gated on required fields). Action.requires lists the ids of actions that must be completed first; blocked_actions() filters a manifest down to actions not yet unblocked by a given set of completed ids:

completed = ["email-input"]
still_blocked = manifest.blocked_actions(completed)  # actions still waiting on something

requires is inferred by the LLM translation step from DOM signals (disabled attributes, aria-disabled, form field proximity) — it's best-effort, not a guaranteed-accurate dependency graph, and won't capture custom JS validation logic.

Action types

button · input · textarea · select · checkbox · radio · other

Locators

Each action may carry a locator with css, role, and name — enough to find and act on the underlying element without guessing a selector yourself. It's best-effort: locator is None if no element on the page plausibly matched the action.

Prefer role/name over css where possible — they hold up better across redesigns, since css can be a brittle positional fallback when the element has no id or name attribute.

action = manifest.action("continue")
if action.locator and action.locator.css:
    page.click(action.locator.css)

Error handling

from manifest_api import AuthenticationError, RateLimitError, APIError

try:
    manifest = client.get("https://example.com")
except AuthenticationError:
    print("Check your API key")
except RateLimitError:
    print("Slow down — rate limit hit")
except APIError as e:
    print(f"Server error {e.status_code}")

Docs

https://omfang.io/docs