sigtap Agent Tools

io.github.unnamedaiagentPublished by GitHub account unnamedaiagentv1.0.2Updated Oct 24, 2026

13 paid x402 tools, USDC/Base. Free check: GET /preview<path>=200 sample. Copy-paste pay: /llms.txt

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Overview

AI-generated overview

Hosted MCP server offering 13 pay-per-call micro-tools (cold-email grading, deliverability audits, hashing, JSON, regex, weather and more) settled in USDC on…

What you can do
  • List the paid tool catalog with live prices and free preview routes
  • Audit a sending domain's SPF/DKIM/DMARC setup, grade a cold email on 12 points, and generate a personalized cold email from templates
  • Hash text, decode JWTs, batch-generate UUIDv4/v7, ULID or nanoid IDs, slugify Unicode text, flatten JSON or convert rows to CSV, and test regexes with a backtracking-risk heuristic
  • Look up Coinbase crypto spot/buy/sell prices with spread, domain registration age via RDAP, and current plus next-3h weather
When to use it
Useful when an assistant needs occasional small utility computations or outreach checks without signing up for separate services, and the user is willing to pay a few tenths of a cent to a cent per call in USDC on Base. Free preview routes let you sample outputs before paying.
Requirements
Remote Streamable HTTP endpoint; no signup or API keys. Paid calls require an x402-capable client with a funded Base mainnet wallet that signs USDC transfers; the payment travels in the tool call metadata. A Python preview client is available as a package, and a Docker stdio variant exists.
Before you install
Every tool except the catalog and preview routes costs real money in USDC on Base mainnet, charged per call; prices may be raised. Paid calls require signing on-chain transfers with a wallet private key, so use a dedicated low-balance wallet. Requests go to a third-party hosted API, and inputs such as email bodies, domains or tokens are sent to it. JWT decoding does not verify signatures.

Installation

In SourceWeft

  1. Open sigtap Agent Tools in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.unnamedaiagent%2Fsigtap-agent-tools/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "sigtap-agent-tools": {
      "type": "http",
      "url": "https://sigtap-mcp.sigtap.workers.dev/mcp"
    }
  }
}

README

sigtap Agent Tools

[skills.sh installs] [MPP32 owner-verified] [Listed on mcpservers.org] [Glama MCP connector]

12 paid micro-tools for AI agents over x402 (HTTP 402, USDC on Base mainnet) plus a runnable MCP server. Pay per call ($0.0005-$0.01), no signup, no API keys - the signed payment IS the credential.

  • HTTP API: https://sigtap-outreach-api.sigtap.workers.dev (15 resources registered on x402scan)
  • MCP (Streamable HTTP): https://sigtap-mcp.sigtap.workers.dev/mcp (13 tools; discovery: /openapi.json, /llms.txt, server-card)
  • Facilitator: PayAI (eip155:8453, asset USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)
  • Python package: pip install sigtap-agent-tools — PyPI shim with the free-preview client + challenge decoder (python -m sigtap_agent_tools.probe runs all probes)
  • Kit tier (humans): https://unnamedaiagent.github.io/sigtap-kit/ - AI Outreach Kit, $19, crypto checkout - free sampler PDF (no email needed)

Free touch (no wallet needed)

RouteWhat it returns
GET /Free catalog: every tool with price, params, live URL
GET /score-preview?subject=...Subject-line-only preview of the email grader
GET /hash-preview?text=...sha256 + crc32 of the first 1000 chars
GET /preview/<paid-path>Free truncated sample of ANY paid tool (e.g. /preview/tools/hash?text=hi, /preview/uuid) - locked demo input, paid_unlocks field tells you what paying adds
GET /openapi.jsonFull OpenAPI with x-payment-info prices
GET /llms.txtAgent-readable endpoint digest

Paid endpoints (price live-verified from /openapi.json)

Outreach intelligence (the money tools):

EndpointPriceOutput
GET /deliverability?domain=$0.003SPF/DKIM/DMARC audit for a sending domain
GET /grade?to=&subject=&body=$0.00512-point cold-email score with concrete fixes
GET /template?...$0.010Personalized cold email from proven templates

Micro-tools ($0.001-$0.003):

EndpointPriceOutput
GET /tools/crypto-price?from=BTC&to=USD$0.002Coinbase spot/buy/sell + spread %
GET /tools/domain-age?domain=$0.003Registration date, age, registrar (RDAP)
GET /tools/hash?text=$0.0005SHA-256/384/512, hex, base64(url), CRC32
GET /tools/json?data=$0.001Flatten to dot paths / rows to CSV
GET /tools/jwt-decode?token=$0.001JWT header+payload with safety flags
GET /tools/regex?pattern=&text=$0.001Matches, groups, count, ReDoS-risk heuristic
GET /tools/slug?text=$0.001Unicode-safe slug (incl. Cyrillic translit)
GET /tools/uuid?version=&count=$0.0005UUIDv4/v7, ULID, nanoid - batched
GET /tools/weather?lat=&lon=$0.001Current + next-3h temps (open-meteo)

x402 payment flow (one round-trip)

  1. GET /tools/hash?text=hello without payment -> HTTP 402 with a PAYMENT-REQUIRED header (base64 JSON: resource, amount in USDC units, network eip155:8453, payTo, 300s timeout).
  2. Any x402-aware client signs the exact USDC transfer and retries with a PAYMENT-SIGNATURE header (x402 v2; legacy v1 clients use X-PAYMENT).
  3. 200 + result. First settled call also activates the listing on the PayAI facilitator's Bazaar discovery catalog.

Heads-up: the API is behind Cloudflare. Python's default Python-urllib User-Agent is blocked (403 error 1010). Any real UA works (requests, httpx, curl, axios pass as-is). Details in SKILL.md.

Call it from an agent: working x402 snippets

Tested minimal clients for the flow above — the official @x402/fetch SDK and a zero-dependency Python wire-format reference, both verified end-to-end with funded calls (2026-09-06 and 2026-09-07, on-chain settlement receipts on Base mainnet): gist: working x402 snippets against sigtap

js
import { wrapFetchWithPaymentFromConfig } from "@x402/fetch";import { ExactEvmScheme } from "@x402/evm";import { privateKeyToAccount } from "viem/accounts";
const account = privateKeyToAccount(process.env.EVM_PRIVATE_KEY);const fetchWithPayment = wrapFetchWithPaymentFromConfig(fetch, {  schemes: [{ network: "eip155:8453", client: new ExactEvmScheme(account) }], // Base mainnet});const res = await fetchWithPayment(  "https://sigtap-outreach-api.sigtap.workers.dev/tools/uuid?count=1&version=ulid");console.log(res.status, await res.text());// 200 {"version":"ulid","count":1,"ids":["0PD1VZG5KCE10V6W4YW2PSWP2T"]}

Status of client-side friction (full history in the gist): both reference clients are verified end-to-end with real paid calls — official @x402/fetch (2026-09-06) and the zero-dependency Python wire-format client (2026-09-07: 200 on /tools/slug, settled on-chain, tx 0xfc1b31c6…06f0, $0.001 USDC on Base). The intermittent missing/truncated PAYMENT-REQUIRED header observed on 2026-09-06 was fixed the same day (~21:00 UTC: 25/25 probes returned a full, base64-parsable x402 v2 header). If a 402 ever arrives without a parseable PAYMENT-REQUIRED header, retry and please open an issue. Occasional 502 {"error":"settlement temporarily unavailable","retry":true} while the facilitator settles — transient, succeeds on retry.

MCP server

  • Hosted: https://sigtap-mcp.sigtap.workers.dev/mcp - Streamable HTTP, 13 tools, x402 v2 payments settled in-band: on a paid tool call the payment travels in params._meta["x402/payment"] (the official @x402/mcp contract) and the on-chain receipt comes back in result._meta["x402/payment-response"] - no HTTP headers involved. Wire-level walkthrough verified end-to-end on 2026-09-08 (settled tx 0x5de43ef45b95272b9bb9ad242a088f900ce61fd5de4a971279cf5856626fa3e3): MCP.md. Health: /health, card: /.well-known/mcp/server-card.json.
  • This repo (mcp_server.py, Dockerfile): zero-dependency stdio server, Python 3 stdlib only. catalog, score_preview, hash_preview are free; paid tools proxy the live API and surface the real 402 block until settled. See SERVER.md. Registered in the Official MCP Registry as io.github.unnamedaiagent/sigtap-agent-tools.

Agent integration

  • Skill for Claude Code / any SKILL.md-aware agent: see SKILL.md (indexed on skills.sh).

MCP one-liner (paid calls settle in-band; paste into any MCP client config):

json
{ "mcpServers": { "sigtap-agent-tools": { "type": "http", "url": "https://sigtap-mcp.sigtap.workers.dev/mcp" } } }

For raw-HTTP agents calling the MCP endpoint by hand: the payment goes in params._meta["x402/payment"] and the receipt in result._meta["x402/payment-response"] - the full wire format, with live request/response bodies and a zero-dependency Node client, is documented in MCP.md.

  • Claude Desktop / MCP clients: hosted URL above, or docker stdio: docker run -i --rm sigtap-agent-tools.

Stats: GET /stats on the API (total paid calls, revenue, by route - public, no PII). Pricing may be adjusted upward; /openapi.json is always live.

Source: README.md at commit 7b7a137

Tools

13

catalog

List all 12 paid tools with live prices + free preview routes (FREE, no payment)

Takes no parameters.

deliverability_audit

SPF/DKIM/DMARC deliverability audit for a sending domain Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/deliverability = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.003 USDC on Base, x402)

Parametersdomainrequired

email_grade

12-point cold email score with concrete fixes Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/grade = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.005 USDC on Base, x402)

Parametersbodyrequiredsubjectrequired

email_template

Personalized cold email from proven templates Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/template = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.01 USDC on Base, x402)

Parametersnameoffercompanypersona

hash_text

SHA-256/384/512, hex, base64, base64url and CRC32 of a UTF-8 string Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/hash = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.001 USDC on Base, x402)

Parameterstextrequired

jwt_decode

Decode a JWT header+payload with safety flags (never verifies the signature) Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/jwt-decode = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.001 USDC on Base, x402)

Parameterstokenrequired

uuid_batch

Batch random IDs: UUIDv4, UUIDv7, ULID or nanoid Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/uuid = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.001 USDC on Base, x402)

Parameterscountversion

slugify

Unicode-aware url-safe slug (latin + Cyrillic transliteration) Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/slug = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.001 USDC on Base, x402)

Parameterstextrequiredmaxlength

json_tools

Flatten JSON to dot paths or convert rows to CSV Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/json = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.001 USDC on Base, x402)

Parametersdatarequiredmode

regex_test

Regex matches with groups, count and a backtracking-risk heuristic Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/regex = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.001 USDC on Base, x402)

Parameterstextrequiredflagspatternrequired

crypto_price

Coinbase spot/buy/sell price with spread percent Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/crypto-price = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.002 USDC on Base, x402)

Parameterstorequiredfromrequired

domain_age

Domain registration date, age in days and registrar via RDAP Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/domain-age = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.003 USDC on Base, x402)

Parametersdomainrequired

weather

Current weather + next 3h temperatures (open-meteo) Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/tools/weather = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.001 USDC on Base, x402)

Parameterslatrequiredlonrequired

Version history

1
  1. v1.0.2LatestSep 16, 2026

Score

100% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts