# Services from signalharness.ai on Zero

> signalharness.ai serves 330 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/signalharness.ai
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/signalharness.ai/health.json

## Services

- [SignalHarness Document Diff](https://www.zero.xyz/c/signalharness-document-diff-da181627/llms.txt): $0.02/call via x402. Computes a structured diff between two text documents, returning added, changed, and removed sections with line counts and hashes.
- [Solana PDA Verification Service](https://www.zero.xyz/c/solana-pda-verification-service-e2242bff/llms.txt): $0.01/call via x402. Mathematically verifies whether a given address is a valid Program Derived Address (PDA) on Solana, returning the canonical bump seed and address derivation result.
- [SignalHarness Heading Structure Audit](https://www.zero.xyz/c/signalharness-heading-structure-audit-4a251dae/llms.txt): $0.005/call via x402. Analyzes HTML or Markdown content to audit heading hierarchy structure, detecting issues and generating a pass/fail report with an outline and findings.
- [SignalHarness URL Normalize & Canonicalize](https://www.zero.xyz/c/signalharness-url-normalize-canonicalize-1887a154/llms.txt): $0.005/call via x402. Normalizes and canonicalizes a URL, decomposing it into origin, path, query, and fragment components while optionally stripping tracking parameters.
- [SignalHarness Sitemap Extract](https://www.zero.xyz/c/signalharness-sitemap-extract-226fd7be/llms.txt): $0.01/call via x402. Parses a sitemap URL or raw sitemap XML and returns a structured list of all URLs, child sitemaps, and metadata found within it.
- [SignalHarness JSON Repair & Normalize](https://www.zero.xyz/c/signalharness-json-repair-normalize-f3cac8f0/llms.txt): $0.005/call via x402. Repairs malformed JSON text, normalizes its structure, and reports duplicate keys and applied fixes
- [SignalHarness XML Normalize & Validate](https://www.zero.xyz/c/signalharness-xml-normalize-validate-cac358bc/llms.txt): $0.01/call via x402. Parses, normalizes, and validates an XML string, returning structural metadata including well-formedness, node count, namespaces, errors, and warnings.
- [Solana Token-2022 Extensions Parser](https://www.zero.xyz/c/solana-token-2022-extensions-parser-5a8d296f/llms.txt): $0.015/call via x402. Parses and decodes Solana Token-2022 account extension data from raw JSON, identifying extension types, configurations, and any anomalies.
- [SignalHarness Solana V0 Message Analyzer](https://www.zero.xyz/c/signalharness-solana-v0-message-analyzer-60d949d0/llms.txt): $0.015/call via x402. Analyzes a serialized Solana versioned (v0) transaction message to extract instruction counts, lookup table usage, key counts, and structural validity warnings.
- [Solana IDL Instruction Decoder](https://www.zero.xyz/c/solana-idl-instruction-decoder-ed67ff31/llms.txt): $0.02/call via x402. Decodes a raw Solana transaction instruction into human-readable arguments and account metadata using a caller-supplied IDL
- [Base L2 Execution Fee Calculator](https://www.zero.xyz/c/base-l2-execution-fee-calculator-b72d2e84/llms.txt): $0.005/call via x402. Calculates the L2 execution fee for a transaction on the Base network given gas parameters, returning effective gas price, execution fee, and OP Stack fee model details.
- [SignalHarness Structured Extract](https://www.zero.xyz/c/signalharness-structured-extract-be2b01d3/llms.txt): $0.02/call via x402. Extracts structured data fields (text, attributes, metadata, JSON-LD) from a given HTTPS URL using configurable field selectors
- [Base Transaction Type Inspector](https://www.zero.xyz/c/base-transaction-type-inspector-a5a3d17c/llms.txt): $0.01/call via x402. Classifies and analyzes a raw Base/Ethereum transaction JSON to determine its EIP type, expected fields, and OP Stack network context
- [CrossChain Wallet Activity Comparator](https://www.zero.xyz/c/crosschain-wallet-activity-comparator-aff5025d/llms.txt): $0.025/call via x402. Compares and analyzes wallet activity across multiple blockchain networks (Solana, Base, Polygon) to identify transaction patterns, counterparties, and cross-chain behavior.
- [Solana PDA Derivation](https://www.zero.xyz/c/solana-pda-derivation-4dc62c1d/llms.txt): $0.01/call via x402. Derives a Solana Program Derived Address (PDA) and its canonical bump seed from a program ID and seed inputs.
- [SignalHarness Text Chunk Structurer](https://www.zero.xyz/c/signalharness-text-chunk-structurer-a03903d8/llms.txt): $0.01/call via x402. Splits a text string into structured chunks with a configurable maximum character size, returning chunk array, count, and a source hash.
- [Base Calldata Decoder](https://www.zero.xyz/c/base-calldata-decoder-21e75988/llms.txt): $0.01/call via x402. Decodes raw Ethereum calldata on Base network, identifying the function name, selector, and decoded arguments from ABI-encoded transaction input data.
- [SignalHarness URL to Markdown Converter](https://www.zero.xyz/c/signalharness-url-to-markdown-converter-abc0644c/llms.txt): $0.01/call via x402. Fetches a webpage at a given HTTPS URL and returns its content as clean Markdown text
- [Polygon Calldata Inspector](https://www.zero.xyz/c/polygon-calldata-inspector-9fbec0f6/llms.txt): $0.01/call via x402. Decodes and analyzes raw Ethereum/Polygon calldata, extracting the function selector, name, arguments, and network context for a given transaction payload.
- [Base ERC-20 Transfer Decode](https://www.zero.xyz/c/base-erc-20-transfer-decode-2a121cc3/llms.txt): $0.01/call via x402. Decodes and extracts ERC-20 token transfer details (sender, recipient, amount, token contract) from raw Base network transaction data supplied by the caller.
- [SignalHarness Base Event Sequence Analyzer](https://www.zero.xyz/c/signalharness-base-event-sequence-analyzer-4d131244/llms.txt): $0.015/call via x402. Analyzes and orders a sequence of Base blockchain events, resolving ambiguities in event ordering and returning structured analysis with chain context.
- [Base Permit Inspect — EIP-2612 Permit Signature Analyzer](https://www.zero.xyz/c/base-permit-inspect-eip-2612-permit-signature-analyzer-1cc7b77f/llms.txt): $0.015/call via x402. Analyzes and validates EIP-2612 permit signature JSON for the Base blockchain, returning decoded fields, risk flags, expiry status, and network context.
- [Base UserOperation Inspector](https://www.zero.xyz/c/base-useroperation-inspector-009d9a36/llms.txt): $0.02/call via x402. Analyzes and decodes a raw ERC-4337 UserOperation JSON for the Base network, returning gas breakdown, call selector, paymaster status, nonce, and network context without simulating on-chain.
- [SignalHarness JSONL Normalize & Validate](https://www.zero.xyz/c/signalharness-jsonl-normalize-validate-15dda4e7/llms.txt): $0.01/call via x402. Normalizes and validates a block of JSONL (newline-delimited JSON) text, returning parsed records, validity counts, and rejected line details.
- [Solana Ed25519 Instruction Inspector](https://www.zero.xyz/c/solana-ed25519-instruction-inspector-279b0583/llms.txt): $0.015/call via x402. Structurally inspects and analyzes Ed25519 signature instructions within a Solana transaction JSON without performing cryptographic verification.
- [SignalHarness Text Deduplication](https://www.zero.xyz/c/signalharness-text-deduplication-74c93acc/llms.txt): $0.005/call via x402. Identifies and groups exact and normalized duplicate strings within a list or document, returning canonical representatives and deduplication metadata.
- [SignalHarness Content Fingerprint](https://www.zero.xyz/c/signalharness-content-fingerprint-999f5fc9/llms.txt): $0.005/call via x402. Computes a SHA-256 cryptographic fingerprint and byte-count of submitted content (HTML, JSON, text, or base64 binary) with normalization metadata for deduplication and integrity verification.
- [Polygon Event Log Decoder](https://www.zero.xyz/c/polygon-event-log-decoder-d107a25b/llms.txt): $0.01/call via x402. Decodes and analyzes Polygon PoS blockchain event logs by parsing raw log data against a supplied ABI to extract structured event arguments and metadata.
- [Solana Versioned Transaction Decoder](https://www.zero.xyz/c/solana-versioned-transaction-decoder-9db50001/llms.txt): $0.015/call via x402. Decodes and analyzes a Solana versioned transaction, extracting its structure including instructions, account keys, header, blockhash, and address table lookups.
- [SignalHarness PDF Extract](https://www.zero.xyz/c/signalharness-pdf-extract-634c999f/llms.txt): $0.03/call via x402. Extracts text, markdown, and metadata from a publicly accessible PDF URL, returning full content with SHA-256 integrity hash.
- [SignalHarness JSON Schema Validate](https://www.zero.xyz/c/signalharness-json-schema-validate-4912333e/llms.txt): $0.005/call via x402. Validates a JSON value against a provided JSON Schema, returning validity status, errors, and failing paths.
- [Polygon Transaction Receipt Consistency Checker](https://www.zero.xyz/c/polygon-transaction-receipt-consistency-checker-7f7d5a94/llms.txt): $0.01/call via x402. Validates that a caller-supplied Polygon transaction receipt matches the corresponding transaction data across key fields, flagging any inconsistencies.
- [SignalHarness Markdown Outline Extractor](https://www.zero.xyz/c/signalharness-markdown-outline-extractor-d2ea851b/llms.txt): $0.005/call via x402. Parses markdown or plain text and extracts a structured outline of headings, titles, and section hierarchy up to a configurable depth.
- [SignalHarness Structured Diff](https://www.zero.xyz/c/signalharness-structured-diff-4cf495c1/llms.txt): $0.01/call via x402. Computes a structured semantic diff between two arbitrary JSON values, returning added, changed, and removed fields with a summary.
- [SignalHarness ABI Function Decode](https://www.zero.xyz/c/signalharness-abi-function-decode-205edee9/llms.txt): $0.01/call via x402. Decodes a raw ABI-encoded Ethereum function call into a human-readable representation, including warnings about the decoded data.
- [SignalHarness Schema.org Extractor](https://www.zero.xyz/c/signalharness-schema-org-extractor-ec55b7c1/llms.txt): $0.01/call via x402. Extracts structured Schema.org entities, relationships, and type metadata from a webpage URL or raw HTML content
- [SignalHarness CSV Normalize & Validate](https://www.zero.xyz/c/signalharness-csv-normalize-validate-16ea9145/llms.txt): $0.01/call via x402. Parses, normalizes, and validates CSV/TSV text data, returning structured rows, headers, rejected rows, and validation issues
- [SignalHarness Web Extract](https://www.zero.xyz/c/signalharness-web-extract-b423d9d8/llms.txt): $0.02/call via x402. Fetches and extracts structured content from a given HTTPS URL, returning visible text, links, images, headings, metadata, Open Graph tags, and JSON-LD data.
- [Base EIP-1559 Transaction Decode](https://www.zero.xyz/c/base-eip-1559-transaction-decode-41401069/llms.txt): $0.01/call via x402. Decodes and analyzes a Base network EIP-1559 (type 0x2) transaction, extracting fields like chain ID, gas parameters, calldata, and network context.
- [SignalHarness Bitcoin PSBT Inspector](https://www.zero.xyz/c/signalharness-bitcoin-psbt-inspector-685237a6/llms.txt): $0.015/call via x402. Inspects and analyzes a Bitcoin Partially Signed Bitcoin Transaction (PSBT), returning decoded details, warnings, and evidence scope about the transaction structure.
- [Polygon Transaction Forensic Report](https://www.zero.xyz/c/polygon-transaction-forensic-report-8d05042e/llms.txt): $0.03/call via x402. Performs a forensic analysis of a Polygon network transaction, cross-checking identity fields, execution details, fees, complexity, and evidence gaps between the transaction and its receipt.
- [Base Transaction Forensic Report](https://www.zero.xyz/c/base-transaction-forensic-report-bf2f75b9/llms.txt): $0.03/call via x402. Analyzes a Base blockchain transaction by cross-checking transaction and receipt fields, computing complexity scores, and surfacing execution, fee, and identity consistency data.
- [SignalHarness Robots Policy Parse](https://www.zero.xyz/c/signalharness-robots-policy-parse-adf843ab/llms.txt): $0.005/call via x402. Fetches and parses a website's robots.txt file to determine whether a given user agent is allowed to crawl a specific URL path
- [Solana Token Authority Risk Analyzer](https://www.zero.xyz/c/solana-token-authority-risk-analyzer-b5126d8a/llms.txt): $0.015/call via x402. Analyzes Solana token authority fields (mint, freeze, delegate, close) from caller-supplied data and returns structured risk flags
- [Polygon Transaction Complexity Analyzer](https://www.zero.xyz/c/polygon-transaction-complexity-analyzer-6c7a120e/llms.txt): $0.02/call via x402. Analyzes the structural complexity of a Polygon PoS transaction by scoring its call depth, inner transactions, instructions, keys, and logs into a complexity band and score.
- [SignalHarness ABI Function Encoder](https://www.zero.xyz/c/signalharness-abi-function-encoder-c5974f41/llms.txt): $0.01/call via x402. Encodes an Ethereum ABI function call into its hex-encoded calldata representation, ready for on-chain transaction submission.
- [Solana SOL Transfer Instruction Decoder](https://www.zero.xyz/c/solana-sol-transfer-instruction-decoder-5f79000e/llms.txt): $0.01/call via x402. Decodes and analyzes a Solana SOL transfer instruction from a raw transaction JSON, extracting source, destination, amount, program ID, and structural validity.
- [Polygon Bridge Withdrawal Inspector](https://www.zero.xyz/c/polygon-bridge-withdrawal-inspector-4523ff74/llms.txt): $0.02/call via x402. Analyzes caller-supplied evidence for a Polygon PoS bridge withdrawal to determine its observed stage, amount consistency, and whether completion can be claimed — without inferring finality beyond what evidence supports.
- [SignalHarness HTTP Header Audit](https://www.zero.xyz/c/signalharness-http-header-audit-8ca35107/llms.txt): $0.01/call via x402. Analyzes HTTP response headers from a URL for security, caching, and discovery best practices, returning categorized findings and pass/fail results.
- [SignalHarness Artifact Verify](https://www.zero.xyz/c/signalharness-artifact-verify-d1155cbd/llms.txt): $0.005/call via x402. Verifies the integrity of a remote artifact by fetching it and comparing its SHA-256 hash, byte size, and MIME type against expected values.
- [SignalHarness HTML Table Extractor](https://www.zero.xyz/c/signalharness-html-table-extractor-d34861ac/llms.txt): $0.01/call via x402. Extracts all HTML tables from a given URL or raw HTML string and returns structured table data.
- [Solana Legacy Transaction Decode](https://www.zero.xyz/c/solana-legacy-transaction-decode-0fe40a26/llms.txt): $0.01/call via x402. Decodes and analyzes a Solana legacy transaction from its serialized bytes, returning structured fields like account keys, instructions, blockhash, and version.
- [Solana Associated Token Account (ATA) Address Deriver](https://www.zero.xyz/c/solana-associated-token-account-ata-address-deriver-4344ab8e/llms.txt): $0.01/call via x402. Derives the canonical Associated Token Account (ATA) address for a given Solana wallet owner and SPL token mint, returning the PDA, bump seed, and program IDs.
- [SignalHarness Solana SPL Approval Analyzer](https://www.zero.xyz/c/signalharness-solana-spl-approval-analyzer-25251092/llms.txt): $0.015/call via x402. Analyzes Solana SPL token approval and transfer instructions in a transaction to ident

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