Measured uptime, price and payment evidence for 19,021 agent services. Reliability, not quality.
Scored across 22 tools
Several tools overlap meaningfully: get_liveness_history vs uptime_history (both return one endpoint's probe series), get_rankings vs get_top_ten vs cheapest_that_works (all ranked lists), and get_service_report vs get_trust_score vs preflight_check (all per-endpoint verdicts). The detailed descriptions do help distinguish intent, so it lands at 'some overlap but descriptions help' rather than worse.
Mixed conventions: some tools follow verb_noun (get_agent_profile, search_agents, find_tool, bulk_score), while many are bare noun or clause phrases (gone_dark, new_services, payment_evidence, price_check, uptime_history, has_it_changed, cheapest_that_works). Readable, but no single predictable pattern and semantically similar tools use different schemes (get_liveness_history vs uptime_history).
22 tools is on the heavy side and the count is inflated by near-duplicate facets (two history tools, three ranking tools, several per-endpoint verdict tools). The broad index domain does justify many of them, but it is borderline rather than well-scoped.
The read surface is strong: discovery (search_agents, find_tool), profiles, scoring, rankings, per-endpoint reports, demand reports, change feeds, history and payment evidence all exist. Missing only write/administrative operations such as registering an endpoint or subscribing to alerts, which are minor given the read-oriented purpose.
Cursor-paginated bulk snapshot of endpoints or resources. PRICED: $0.25 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Returns a 1000-record page. Price is per page, not per record. Pass the returned cursor to continue.
Inputs: type, cursor, payment, protocol.
Bulk scoring. PRICED: $0.02 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Post up to 1000 domains, get one scored row back per row in: score, grade, 90-day uptime, probe count and distinct on-chain payers. The shape an enrichment pipeline expects.
Inputs: days, payment.
Cheapest that works. PRICED: $0.01 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Best value in one capability category: observed price ranked against our own measured uptime. A cheap service that is down is worth nothing, so price alone is not the ranking.
Inputs: category (required), limit, payment.
Tool finder. PRICED: $0.002 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Find services by the tools they actually publish, searching the real tool lists of the 6,530 services that expose one rather than their marketing text.
Inputs: q (required), payment.
Retrieve a full profile for a specific agent or endpoint by its numeric ID or identifier URI. Returns protocol detection, liveness history, on-chain payment evidence, MCP tools list, and A2A skills. FREE for the first 50 calls a day per caller, then $0.02 in USDC on base via x402. Over the allowance, call without payment to receive the exact payment requirements, then call again with payment to be served.
Inputs: id (required), payment.
Free preview of the AgentIndex Builder Demand Report: the top three themes builders are asking about right now, with signal counts. The full report -- evidence, supply gaps, release inventory and recommendations -- is the priced tool get_demand_report.
Inputs: days.
Builder Demand Report: what builders are asking for right now, and where demand has no supply. PRICED: $0.05 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Themes ranked by how often they recur across a nightly-mined corpus of developer questions, forum discussion and search demand, each with the underlying signals as evidence and a stated implication. Crossed against our own measured index to report supply per theme, so a capability that is heavily asked for and rarely built shows up as a number rather than a hunch. Includes a current-version inventory for the main agent protocol projects. Caveats travel inside the payload.
Inputs: days, payment.
Change feed of recently added, changed or newly dark endpoints. PRICED: $0.05 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Returns up to 500 recent endpoint changes, filterable by protocol and time window. Intended to be called repeatedly in place of re-crawling the index.
Inputs: since, payment, protocol.
Liveness attestation and retained probe history for one endpoint. PRICED: $0.01 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Probes the endpoint live at request time and returns that alongside the complete retained probe series -- every observation oldest-first, uptime percentage, observed-day count, and each up/down transition with the timestamp it changed and how long the previous state had held. History is a function of elapsed time and cannot be reconstructed after the fact.
Inputs: id (required), payment.
The full ranked table of every scored service. PRICED: $0.25 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Every service we hold probe history for, scored out of 100, ordered best first, each tagged with the categories it leads on. Page with limit and offset. Services we have never probed are absent rather than ranked last, because no history is an absence of evidence, not a bad verdict.
Inputs: limit, offset, payment.
One-page report on a single indexed service, ending in a verdict. PRICED: $0.02 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Live status, 30 and 90 day uptime computed from our own probe history, advertised price, on-chain payment evidence with distinct payer count, TLS issuer and expiry, the jobs the service declares, and three closest alternatives with their own numbers. Closes with safe / risky / dead and the reason. Every figure cites the table it came from. A domain we do not hold is refused free of charge rather than sold an empty report; check first with the free coverage lookup at /covered/{domain}.
Inputs: domain (required), payment.
The ten best services in one capability category today. PRICED: $0.02 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Ranked by a score out of 100 built only from what we measured: liveness history over the last 90 probes, on-chain payment evidence, how many independent registries list it, how many protocols it genuinely answers on, and how completely it describes itself. Frozen nightly after the crawl, so every buyer gets the same list for the same day. A service is placed in a category by the names of the tools it publishes and appears in at most three, so the ten lists are genuinely different from each other.
Inputs: category (required), payment.
Measured-signal trust score for one endpoint. PRICED: $0.02 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Scores an endpoint on liveness history, on-chain payment evidence, cross-registry corroboration and protocol richness. Every input is independently measured by us; no self-reported field contributes.
Inputs: id (required), payment.
What came alive and what went dark across the whole index in the last seven days. PRICED: $0.05 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Services that started answering and services that stopped, with index-wide totals, over a window you choose up to 30 days. Rebuilt hourly and served identically to every buyer, so it costs the same to read whether you are first or hundredth.
Inputs: days, payment.
Gone dark. PRICED: $0.005 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Services that used to answer and have stopped. Never-alive services are excluded, so this lists things that broke rather than things that never worked.
Inputs: days, payment.
Change watch. PRICED: $0.002 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Has this endpoint changed since a moment you name. Stateless by design: you pass the time you last looked, we compare it against our probe record. No account and no subscription to administer.
Inputs: target (required), payment.
New services. PRICED: $0.01 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Services that appeared recently, roughly 170 a day. New means new to us; a service may predate our first sight of it.
Inputs: days, payment.
Payment evidence. PRICED: $0.002 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. On-chain payment evidence for one service: how many payments, how many distinct paying wallets, first and last seen. Read off the chain, not off a claim. Counts are per receiving wallet, so one operator on several hostnames shows the same totals on each.
Inputs: target (required), payment.
Pre-flight check. PRICED: $0.001 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. Is this endpoint alive, how long we have known it, what protocols it answers on, what it charges, and whether real money has ever reached it. Answered from our own probe record rather than the service's own claims. First 500 calls a day are free.
Inputs: target (required), payment.
Price check. PRICED: $0.001 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. What this endpoint charges as we last observed it, not as it advertises, with the live payment terms and whether they match the published ones.
Inputs: target (required), payment.
Search the AgentIndex for AI agents, MCP servers, A2A agents, and x402-gated APIs by capability keyword. Returns ranked results with type, description, URL, and tags. FREE for the first 50 calls a day per caller, then $0.005 in USDC on base via x402. Over the allowance, call without payment to receive the exact payment requirements, then call again with payment to be served.
Inputs: capability (required), type, limit, payment.
Uptime history. PRICED: $0.002 in USDC on base via x402 -- no account, no API key, no invoice. Call without payment to receive the exact payment requirements, then call again with payment to be served. The 90-day probe record for one service, probe by probe. This is the part nobody who started later can reconstruct.
Inputs: target (required), payment.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
Proof, not ratings: verified paid agent-job records on Arc + a $0.05 signed Proof Check.
Route agent services by observed price and public usage evidence.
Paid agent trust checks, receipt verification, research, data work, and monitoring.
Agents pay for work and prove what happened.
Add one secure layer between your agents and this server.
