# Services from witness.holoweave.org on Zero > witness.holoweave.org serves 16 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero. Canonical page: https://www.zero.xyz/host/witness.holoweave.org Live health (JSON, refreshed every minute): https://www.zero.xyz/host/witness.holoweave.org/health.json ## Services - [Holoweave URL Witness — Signed URL Evidence](https://www.zero.xyz/c/holoweave-url-witness-signed-url-evidence-7346609d/llms.txt): $0.01/call via x402. Fetches a public URL and returns a cryptographically signed, timestamped attestation of its HTTP status, response headers, and SHA-256 body hash, with optional change detection against a previously pinned hash. - [Holoweave Witness — Transaction Finality Attestation](https://www.zero.xyz/c/holoweave-witness-transaction-finality-attestation-5eb9aad4/llms.txt): $0.01/call via x402. Returns a signed, independent attestation of a Base blockchain transaction's outcome, including USDC transfer details, finality status, and confirmations — without trusting the payment facilitator. - [Witness AI Permission Checker](https://www.zero.xyz/c/witness-ai-permission-checker-b6bb10a8/llms.txt): $0.01/call via x402. Fetches and verifies whether a named AI agent is permitted to fetch or train on a given URL, by reading robots.txt, noai meta tags, TDM reservations, and X-Robots-Tag signals, returning a signed attestation verdict. - [Witness Holoweave URL Read with Signed Attestation](https://www.zero.xyz/c/witness-holoweave-url-read-with-signed-attestation-20bccc22/llms.txt): $0.01/call via x402. Fetches a public web page as plain text and returns both the extracted content and a cryptographically signed provenance record (URL, timestamp, HTTP status, SHA-256) attesting to what was retrieved. - [Witness MCP Tool Surface Drift Detector](https://www.zero.xyz/c/witness-mcp-tool-surface-drift-detector-def83a60/llms.txt): $0.01/call via x402. Compares an MCP server's current tools/list against a signed baseline digest and returns a cryptographically signed attestation listing every tool added, removed, or silently redefined. - [Holoweave Witness — URL Witness (Batch URL Verification with Signed Attestations)](https://www.zero.xyz/c/holoweave-witness-url-witness-batch-url-verification-with-signed-3a6d1333/llms.txt): $0.05/call via x402. Fetches and verifies up to 10 URLs, returning signed Ed25519 attestations with HTTP status, body hash, change detection, and optional full-text extraction. - [witness.holoweave.org Transaction Finality Verification](https://www.zero.xyz/c/witness-holoweave-org-transaction-finality-verification-3cefe2e6/llms.txt): $0.05/call via x402. Verifies finality and transfer details of Base blockchain transactions by tx hash or x402 payment-response header, returning a signed attestation with pass/fail verdict - [Holoweave Witness WBA Signature Verifier](https://www.zero.xyz/c/holoweave-witness-wba-signature-verifier-f0ebe4d8/llms.txt): $0.01/call via x402. Verifies that an HTTP request's Ed25519 signature (RFC 9421) is valid against the agent's published key directory - [autobus — JWK Set Witness (keys-witness)](https://www.zero.xyz/c/autobus-jwk-set-witness-keys-witness-bd52971a/llms.txt): $0.01/call via x402. Fetches a JWK Set URL, verifies RFC 7638 key thumbprints and RFC 9421 Ed25519 signatures, and returns a signed attestation of the results with optional change detection against a prior digest or pinned thumbprints. - [autobus — WBA Self-Check (Web Bot Auth Debugger)](https://www.zero.xyz/c/autobus-wba-self-check-web-bot-auth-debugger-2b35f552/llms.txt): $0.01/call via x402. Debugs why a signed bot HTTP request is rejected by verifying RFC 7638 key ID thumbprints, RFC 9421 Ed25519 signatures, and per-verifier acceptance rules, returning a signed attestation with a pass/fail verdict. - [Agent Card Witness — AI Agent Identity Verification](https://www.zero.xyz/c/agent-card-witness-ai-agent-identity-verification-21654892/llms.txt): $0.01/call via x402. Fetches, verifies, and cryptographically attests to an AI agent's published agent card, detecting changes in card content or skills since a previous check. - [MCP Tool Surface Digest & Attestation](https://www.zero.xyz/c/mcp-tool-surface-digest-attestation-aae653a4/llms.txt): $0.01/call via x402. Computes a stable, signed digest over an MCP server's tools/list (tool names, descriptions, and inputSchemas) and returns a cryptographically signed attestation as a baseline for future integrity comparisons. - [WBA Thumbprint Validator](https://www.zero.xyz/c/wba-thumbprint-validator-80fb9b8b/llms.txt): $0.01/call via x402. Validates that a given keyid matches the RFC 7638 thumbprint of a key published in an agent's JWKS key directory - [autobus MCP Server Attestation](https://www.zero.xyz/c/autobus-mcp-server-attestation-f9b44d86/llms.txt): $0.03/call via x402. Attests the live tool surface of an MCP server against its registry definition, returning a signed Ed25519 verdict on whether the server matches its published version - [autobus MCP Registry Drift Detector](https://www.zero.xyz/c/autobus-mcp-registry-drift-detector-b8a22bb9/llms.txt): $0.01/call via x402. Compares a live MCP server's current tool surface against its registry entry and returns a signed attestation indicating whether they match - [Witness Holoweave Signature Acceptance Check](https://www.zero.xyz/c/witness-holoweave-signature-acceptance-check-0196e7be/llms.txt): $0.01/call via x402. Checks whether a signed HTTP request would be accepted by major bot-auth verifiers (Cloudflare, AWS WAF, Akamai, Vercel) according to the draft-meunier-web-bot-auth-architecture spec Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. - [Zero catalog index](https://www.zero.xyz/llms.txt)