Probe V0

io.github.lexbrittenPublished by GitHub account lexbrittenv0.1.0Updated Oct 27, 2026

Experimental MCP server for current empirical verification of explicit public HTTPS endpoint claims.

VerifiedStreamable HTTPWeb executableDeveloper ToolsSecurity & Monitoring

Overview

AI-generated overview

Experimental remote MCP server that lets an assistant directly observe public HTTPS endpoints to verify claims about status codes, headers, JSON values or…

What you can do
  • Verify a claim about a public HTTPS URL by making one bounded GET or HEAD request and checking an expected status, exact header value, JSON Pointer value or literal body substring
  • Optionally follow up to three redirects when explicitly enabled, otherwise only the first response is observed
  • Retrieve up to 20 persisted observations for an existing experiment ID without making a new request
  • Compare repeated results, PASS/FAIL/ERROR counts, agreement, and whether the verdict changed between the two latest decisive observations
When to use it
Useful when an assistant needs to confirm a current, explicit claim about a public HTTPS endpoint rather than relying on web search, documentation or model inference, and when repeated or historical observations of the same check matter.
Requirements
A remote streamable HTTP endpoint; no package, account, API key or header is declared. Targets must be public HTTPS hostnames on port 443, and the public V0 requires freshness_seconds to be exactly 300.
Before you install
It makes outbound requests to public URLs on your behalf and persists timestamped observations that can be retrieved later by experiment ID. Redirect following is opt-in and restricted, but the server states it offers no complete DNS-rebinding guarantee, no uptime or SLA commitment, no authentication feature and no pricing commitment, and it is experimental V0.

Installation

In SourceWeft

  1. Open Probe V0 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.lexbritten%2Fprobe/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": {
    "probe-v0": {
      "type": "http",
      "url": "https://probe-evidence.probe-lab.workers.dev/mcp"
    }
  }
}

README

Probe (experimental V0)

Probe lets AI agents empirically verify current claims about public HTTPS endpoints by making a bounded direct observation. This differs from web search or documentation, which report what sources say, and from model inference, which is not a live observation.

Probe persists timestamped, freshness-aware evidence so a sufficiently recent matching observation can be reused and historical observations can be compared.

V0 is intentionally narrow: public HTTPS hostname URLs on port 443; GET or HEAD; HTTP status, exact header, exact JSON Pointer value, or literal body-substring assertions. Public V0 requires freshness_seconds exactly 300.

Redirect following is opt-in with follow_redirects=true, limited to three 301/302/303/307/308 hops. Every destination must satisfy the same HTTPS, hostname, port, credential, query, fragment, and private/local safety restrictions. With the default false, Probe observes only the first response. Probe must not be used when the user's actual claim requires fetching an unsupported destination.

Probe does not provide a complete DNS-rebinding guarantee, uptime guarantee, SLA, authentication feature, or pricing commitment. It is experimental V0.

Source: README.md at commit 4958606

Tools

2

verify_http_claim

Verify Live HTTP Claim

Use this to verify a current public HTTPS claim by direct observation rather than web search, documentation, browser inference, or shell/curl. Use for explicit assertions that a GET/HEAD currently returns an expected HTTP status, exact header value, JSON value at a JSON Pointer, or body substring. It evaluates assertions, persists bounded evidence, reuses sufficiently fresh matching evidence, and summarizes recent observations. follow_redirects defaults to false; when true, Probe manually follows at most 3 validated HTTPS redirects. Every fetch uses redirect: manual. V0 supports only public HTTPS URLs without credentials, query strings, fragments, IP literals, or non-443 ports. Redirect validation is hostname/policy based; the Worker cannot guarantee protection against DNS rebinding between validation and platform DNS resolution.

Parametersurlrequiredmethodassertionsrequiredfollow_redirectsfreshness_seconds

probe.history

Inspect Historical HTTP Evidence

Retrieve up to 20 persisted observations for an existing Probe experiment ID without making a new HTTP request. Use after verify_http_claim to inspect repeated results, PASS/FAIL/ERROR counts, agreement, or whether the observed verdict changed between the two latest decisive observations. This is historical evidence lookup, not a current live verification; use verify_http_claim when freshness or present endpoint behavior matters.

Parameterslimitprobe_idrequired

Version history

1
  1. v0.1.0LatestSep 16, 2026

Score

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