Capabilities

Foragent exposes browser operations as discrete A2A capabilities. Callers invoke capabilities by name; Foragent handles the browser mechanics.

Advertised capabilities (v0.2)

• browser-task — generalist, spec §5.2. LLM-in-the-loop planner that drives a real browser to accomplish a free-form intent. Shipped in step 6; step 7 added skills + memory priming (spec §5.6).
• learn-form-schema — specialist (phase-1, spec §5.5). Introspects a form and returns a typed FormSchema persisted at sites/{host}/forms/{slug}.
• execute-form-batch — specialist (phase-3, spec §5.5). Submits rows against a learned schema, streaming per-row progress over A2A.

Three v0.1/v0.2 specialists have been removed as browser-task subsumes them. The project is pre-public so no deprecation path was required:

• post-to-site — removed in step 7. browser-task + the seeded sites/bsky-app/login skill cover the use case.
• fetch-page-title — removed in step 9. Was a milestone-1 smoke target; browser-task with a simple intent produces the same result.
• extract-structured-data — removed in step 9. browser-task with a “return JSON: {…}” intent produces the same result. Its typed input shape also lacked the mandatory allowlist required by spec §7.1; the generalist enforces that by design.

browser-task input shape

JSON in the first text part, or field-by-field metadata:

{
  "intent": "free-form description of what to accomplish",
  "allowedHosts": ["bsky.app", "*.example.com", "*"],
  "url": "optional absolute http(s) starting URL",
  "credentialId": "optional broker reference",
  "maxSteps": 60,
  "maxSeconds": 120
}

• intent — required. Free-form.
• allowedHosts — required, non-empty (spec §7.1). An empty list rejects. Supports exact hosts, *.domain subdomain wildcards, and * for unrestricted. Off-list navigations are aborted inside the browser context before Playwright issues the request.
• url — optional. If provided, must match the allowlist.
• credentialId — optional. Resolved but not exposed to the planner yet; reserved for a typed login tool in a later step.
• maxSteps — default 60, ceiling 150. Enforced tool-side via BrowserTaskState.BudgetExhausted; once exceeded, tools return a “call done or fail” message and refuse further work.
• maxSeconds — default 120, ceiling 600. Enforced via a linked CancellationTokenSource.

browser-task output shape

A JSON object in a single text part:

{
  "status": "done" | "failed" | "incomplete",
  "summary": "one-sentence human-readable result",
  "result": "optional structured result text (e.g. extracted value)",
  "steps": 7,
  "navigations": ["https://host/path", "..."]
}

incomplete means the budget was exhausted before done/fail was called. For extraction-style tasks, instruct the planner to return JSON via the result field — e.g. intent "Open https://shop.example/p/42 and return {\"name\":..., \"price_usd\":...} as JSON in the result field.". The planner is not schema-enforced the way extract-structured-data used to be, so keep the target shape explicit in the intent.

browser-task tool surface

Exposed to the planner via [AIFunction] wrappers over IChatClient (spec Appendix A #16 — no MCP sidecar). Refs are Playwright aria-ref ids and are valid only within the snapshot they came from.

• snapshot() — ref-annotated aria tree of the current page.
• navigate(url) — load a URL; host must be on the allowlist.
• click(ref) — click by ref.
• type(ref, text) — fill by ref.
• wait_for(ref, timeoutSeconds?) — wait for visibility.
• done(summary, result?) — mark complete.
• fail(reason) — mark failed.

Design principles

• Capabilities operate at the task level, not at the DOM-operation level.
• Each capability invocation gets an isolated BrowserContext (spec §3.5).
• Per-task host allowlists are mandatory (spec §7.1).
• Credential references are passed by ID; values are resolved inside Foragent and never cross A2A boundaries (spec §6.1).
• Prohibited capabilities — account creation, financial transactions, modifying security permissions — are out of scope regardless of implementation ease (spec §7.3).