All servers · APIs & integrations · Payments & accounting

FetchSandbox

io.github.fetchsandbox/mcp · v0.7.30

Measured by MCP Station

Description written by the publisher, not verified

A deterministic verification engine for agents. Proves a fix: fails on the old code, passes on new.

Connect

claude mcp add --transport http mcp https://fetchsandbox.com/mcp/v1

{
  "mcpServers": {
    "mcp": {
      "url": "https://fetchsandbox.com/mcp/v1"
    }
  }
}

Tools as reported by the server

• coach
  Conversational integration coach for FetchSandbox. Server-side orchestrator that walks the user through adding an API integration (payments / email / auth / etc.) — intake the goal, elicit domain-aware discovery questions from the spec's brain.yaml, route to the right workflow, prove the contract vi
• get_job
  Retrieve the SAME running find_bugs, fix_bug, prove_fix, verify_behavior or validate_integration job (including requirements planning). Follow next_tool_call until status is done or error. Never restart the original tool to poll. A proposed plan is not execution proof; a running response is not proo
• guide
  ROUTE a symptom to the provider behaviour that explains it. Use this when the user names a provider or a domain (payments, email, auth, SMS, subscriptions) and you need to know what that provider ACTUALLY does — not what its docs say, and not what can be inferred from reading the integration code. R
• quickrun
  Run a curated reference workflow against a KNOWN, bundled spec (stripe, clerk, descope, resend, twilio, and 50+ others) in ONE call — it spins up the sandbox by slug, so you do NOT need import_spec or a sandbox_id first. Use this when exploring the bundled provider contract: call `guide` on their pr
• validate_integration
  Completion rule: a request to verify an app includes its applicable failure checks without another user prompt. When verification_continuation.required is true, continue in this agent: inspect pending_checks, preserve every declared check and its assertions, implement supported actions, and rerun a
• list_workflows
  List the named, runnable workflows for a known provider slug or imported spec. Workflows are realistic multi-step API journeys (e.g. 'create customer → attach payment method → create subscription'). Known provider slugs need no import. Use this for exploration ("what can I do?", "show me the flows")
• run_workflow
  Execute ONE specific workflow by name and return its step-by-step trace PLUS a `share_url` — a public, replayable proof URL that renders the full timeline (every request, response, webhook event) for this run. The share_url is the canonical 'here's what happened' artifact: surface it verbatim in any
• verify_behavior
  Prove a known fix survives a bug — the 'prove' half of reproduce→prove. The backend spawns a buggy AND a fixed reference handler and fires the bug_pattern's probes at both, returning the side-by-side diff (e.g. the buggy handler double-charges on a duplicate webhook, the fixed handler dedupes). Call

Tool changes

• 2026-10-20: coach, get_job, guide, quickrun, validate_integration, list_workflows, run_workflow, verify_behavior
• 2026-10-19: coach, get_job, guide, quickrun, validate_integration, list_workflows, run_workflow, verify_behavior
• 2026-10-16: coach, get_job, guide, quickrun, validate_integration, list_workflows, run_workflow, verify_behavior

Repository · Website · JSON · Text for agents · Registry updated 2026-10-19