API & MCP

Everything a person can do on usefulweb.site, a program or AI agent can do with the same inputs and get the identical result.

HTTP API

• GET https://usefulweb.site/api/v1/tools – catalog
• GET https://usefulweb.site/api/v1/tools/{id} – inputs, output schema, examples
• POST https://usefulweb.site/api/v1/tools/{id}/calculate – run a tool
• GET https://usefulweb.site/api/v1/workflows · POST https://usefulweb.site/api/v1/workflows/{id}/run
• OpenAPI 3.1: /openapi.json · /openapi.yaml
• Errors: application/problem+json; 422 includes per-field errors.

Every result contains

inputs (normalised, defaults applied), summary, result (validated against the published schema), units, assumptions, sources, warnings, computedAt and links.

MCP (Model Context Protocol)

• Streamable HTTP endpoint: https://usefulweb.site/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
• Tools: headerlens, cancellation_navigator, deadline_decoder, decision_simulator, form_translator, how_long_will_it_last, is_it_worth_it, life_admin_generator, repair_or_replace, true_cost_calculator, bill_detective, break_even_explorer, bulk_buy_brain, hidden_fee_finder, inflation_time_machine, price_per_everything, salary_reality_check, subscription_stack, warranty_value_calculator, food_storage_guide, household_maintenance_calendar, jet_lag_planner, leftover_chef, moving_box_planner, room_layout_optimizer, travel_connection_checker, will_it_fit, ai_answer_verifier, error_message_translator, file_format_doctor, privacy_policy_decoder, prompt_to_tool_router, scam_signal_checker, screenshot_to_steps, website_change_explainer, accessibility_fixer, before_you_sign, digital_estate_organizer, disaster_prep_builder, compatibility_engine, what_changed_in_this_law, a11y_snapshot, citeshape, datafresh, filefit, localekit, ruledate, timefair, unitproof, account_abstraction_explorer, blockchain_incident_replay, bridge_transfer_tracker, cross_chain_transaction_explorer, dao_governance_explorer, defi_liquidation_explorer, gas_fee_intelligence_explorer, mev_explorer, rollup_batch_explorer, smart_contract_relationship_graph, contract_upgrade_explorer, stablecoin_flow_explorer, token_unlock_explorer, transaction_decoder, wallet_permission_explorer, asn_relationship_explorer, bgp_route_explorer, cdn_behavior_explorer, certificate_transparency_explorer, dns_certificate_explorer, domain_history_graph, email_infrastructure_explorer, global_dns_explorer, http_technology_explorer, internet_outage_atlas, ipv6_readiness_explorer, artifact_provenance_explorer, container_image_explorer, cve_relationship_graph, dependency_vulnerability_explorer, oauth_permission_explorer, open_source_trust_explorer, package_ecosystem_graph, sbom_explorer, security_advisory_timeline, security_configuration_scanner, api_explorer_of_explorers, cicd_failure_explorer, cron_job_explorer, data_lineage_explorer, distributed_trace_explorer, kubernetes_event_explorer, openapi_diff_explorer, query_plan_visualizer, serverless_performance_explorer, terraform_drift_explorer, agent_permission_graph, ai_agent_tool_explorer, ai_model_compatibility_explorer, tool_call_trace_explorer, ai_website_readiness_explorer, llm_cost_explorer, mcp_server_explorer, model_behavior_regression_explorer, rag_citation_debugger, structured_output_validator, energy_grid_explorer, internet_archive_change_explorer, public_spending_explorer, satellite_change_explorer, software_adoption_explorer, explore, workflow_moving_home, workflow_suspicious_message, workflow_subscription_cleanup
• Local stdio connector: node src/mcp-stdio.ts

{
  "mcpServers": {
    "usefulweb": { "type": "http", "url": "https://usefulweb.site/mcp" }
  }
}