Pricing

The short version

• Agents (MCP / API): $0.008 to $0.025 per tool call, billed via Stripe metered subscriptions. First 50 calls free per IP across the entire grid.
• Humans (web UI): 3 to 8 free calls per tool per day. Unlimited for 24 hours with a $1 Day Pass.
• No tiers. No seats. No subscriptions. You only pay for what you call. Tool discovery (search_utility_grid) is unconditionally free.

MCP / API pricing — per call, by tier

Every tool is priced by its tier. Tier values are stable and never change mid-month; if we ever revise them you'll get notice via the MPP challenge response's unit_price_micros field.

Prices are denominated in micros (millionths of a US dollar) inside the MPP protocol so agents can do exact integer arithmetic without floating-point drift. 8000 micros = $0.008.

Free tier (MCP / API)

Every IP gets 50 free tool calls across the entire grid for life — no daily reset, no per-tool budget, no signup. This is enough to evaluate three or four tools (~10 test calls each), build a dependency, and decide whether to add the obfus.link MCP server to a production pipeline.

Once the budget is exhausted, the next call returns HTTP 402 Payment Required with the full MPP challenge payload: a payment_intent_url the agent can POST to, the exact unit_price_micros for the requested tool, and a Stripe publishable key. Agents enroll programmatically — no human in the loop.

search_utility_grid is exempt from both the free tier limit and Stripe billing. Tool discovery is free forever so agents can inventory the grid before spending a token budget on an invocation.

Web UI rate limits (per IP, per day)

The browser-facing tools are governed by per-tier daily limits scoped to a single tool and a single IP. The limits are calibrated so a developer evaluating the grid can hit every tool of interest without paying, but sustained automated scraping is blocked.

• Tier 3 (premium): 3 calls per tool per day
• Tier 2 (differentiated): 5 calls per tool per day
• Tier 1 (commodity): 8 calls per tool per day

Hitting a limit returns a clean error message inline in the tool widget — no modal, no CAPTCHA. The error suggests the $1 Day Pass for users who need more, and points heavier users at the MCP endpoint where billing is per-call rather than per-day.

$1 Day Pass (web UI)

A single $1 USD charge via Stripe Checkout unlocks unlimited tool usage from the browser for 24 hours. The pass sets an httpOnly cookie signed with HMAC-SHA256; no account is created, no email required, no PII stored. Closing your browser, switching IPs, or rotating networks does not invalidate the pass — it lives entirely in the cookie. Buy it at /api/day-pass/checkout.

The Day Pass applies only to the web UI. The MCP endpoint uses its own metered billing path (per-call) and does not consume Day Pass credits. Agents should use SPT, not Day Pass.

Shared Identity Layer (cross-property)

obfus.link is the first property in the Subether Labs utility grid. Agents authorised on any current or future Subether property may present a single x-subether-shared-token header and bypass the per-property 402 challenge — usage is billed against your existing Subether account.

Token issuance lives at the central identity service (still under construction). When it ships, obfus.link auto-recognises SIL tokens with no operator action required. Until then, the SPT path remains the supported method.

What you pay for vs what you don't

You pay for tool execution. That's the entire scope: one charge per successful call. You don't pay for failures (a tool returning SECURITY_VIOLATION or INPUT_MALFORMED does not increment your meter). You don't pay for the manifest (/.well-known/mcp), tool discovery (search_utility_grid), or the MAIO surfaces (/tool/[slug]/json + /tool/[slug]/md). Those are infrastructure — free forever.

Documentation

For the protocol-level details — MPP challenge schema, retry semantics, Stripe Billing Meter integration, SIL token format — see obfus.link/docs/mcp-auth. For billing questions: billing@obfus.link.