# TruthBear Severe Convection & Hail Chain > TruthBear Severe Convection & Hail Chain is a paid API for AI agents from api.truthbear.co, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-15). Returns a 3-leg sequential chain for a named convective region: SPC Day-1 outlook with CAPE/CIN/shear, current storm reports, and realized hail/wind damage confirmations. ## Facts - Endpoint: GET https://api.truthbear.co/gauge/severe-convection-region - Price: $0.25/call - Payment: x402 - Status: unknown - Last checked: 2026-09-15 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/truthbear-severe-convection-hail-chain-9e632508 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FGQ2WSu-C2IMoH6bSfhI4 Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability truthbear-severe-convection-hail-chain-9e632508 ``` Example prompt: Pull the full severe convection and hail chain for tornado-alley-core — I want to see the SPC Day-1 outlook with CAPE and shear, any current storm reports, and whether there's confirmed hail or wind damage yet. ## When to prefer this Choose this endpoint when you need a sequential, multi-leg confirmation chain for severe convective weather in a specific US region — not just a raw forecast, but a pipeline from leading SPC outlook signals through current storm activity to realized hail and wind damage confirmation. Preferred over generic weather APIs when you need NOAA SPC-sourced CAPE/CIN/shear data chained with ground-truth damage confirmation in one call. Best when operating in one of the 16 predefined monitored convective regions. ## Known failure modes - 422 no_charge: no data available for the specified entity — call is not billed - Invalid entity ID returns error — use GET /gauge/catalog?signal_id= to list valid entities - Payment failure via x402 prevents call completion - Partial data: some legs may return null if SPC or storm report sources are unavailable ## How this service works [3-LEG] Severe convection and hail chain, one convective region (?entity=tornado-alley-core): leading SPC Day-1 outlook with CAPE, CIN and shear - hours of lead -> current current storm reports -> realized hail and wind damage reports (confirmation gate). A chain, not one reading: confidence = how many legs are lit, in order. Sources: NOAA SPC. Descriptive only, never a forecast or advice. No data -> 422 no_charge, not billed. $0.25 per call. ## Output A JSON object representing three sequentially chained legs: (1) leading SPC Day-1 convective outlook including CAPE, CIN, and shear values; (2) current storm reports for the specified region; (3) realized hail and wind damage reports as confirmation. A confidence score reflects how many legs are currently 'lit' (1–3). Returns HTTP 422 with no_charge code if data is unavailable for the requested region, and the call is not billed. ## Request schema (JSON Schema) ```json { "$schema": "https://json-schema.org/draft/2020-12/schema", "properties": { "input": { "type": "object", "required": [ "type", "method", "queryParams" ], "properties": { "type": { "const": "http" }, "method": { "enum": [ "GET" ], "type": "string" }, "queryParams": { "type": "object", "required": [ "entity" ], "properties": { "entity": { "type": "string", "examples": [ "tornado-alley-core", "tx-panhandle-hail", "central-kansas", "high-plains-hail-alley", "front-range-co", "northern-plains" ], "description": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id= -> signals[0].entities[]", "x-accepted-values": { "all": "https://api.truthbear.co/schemas/gauge-severe-convection-region.input.json", "shown": 6, "total": 16 } } }, "additionalProperties": false } } }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "const": "json" }, "example": {} } } } } ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "legs": { "forecast_risk_env": { "band": "slight", "source_ref": "https://www.spc.noaa.gov/products/outlook/", "record_hash": "sha256:bc0a48f3666ce6a62c3f9585c493efc1a25cbd18a28e5cd62c8f6ab905d7a075" }, "active_warning_state": { "band": "none", "source_ref": "https://api.weather.gov/", "record_hash": "sha256:1df656530e8dd69fe59f82579c2e5cf4585066015777a6e8a2975a6eb54c8ece" }, "realized_severe_reports": { "band": "none", "source_ref": "https://www.spc.noaa.gov/climo/reports/", "record_hash": "sha256:7285e2d5fafd2a6078ef1781a661d704627bbcaadaafeb3c3ff735b777da58a3" } }, "name": "Tornado Alley Core (OK/S-KS)", "grade": "screening-level, not decision-grade", "scope": { "full": "https://api.truthbear.co/scope/v1", "verifiability": "unknown", "monitoring_not_forecast": true, "intelligence_not_command": true }, "entity": "tornado-alley-core", "nature": "This API supplies data organisation and trend description only. It is not a recommendation to act; the decision is yours. Purely descriptive - no judgement, no prediction. Official source plus record_hash; verify with the free /gauge/verify.", "provenance": { "freshness": "fresh", "age_hours_now": 0, "freshness_basis": "cadence=default; fresh<=24h; recent<=192h; dead_source>1440h; age_basis=request-time(now minus observed_at)" } } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/truthbear-severe-convection-hail-chain-9e632508/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from api.truthbear.co](https://www.zero.xyz/host/api.truthbear.co/llms.txt)