Documentation Index

Fetch the complete documentation index at: https://docs.tensorcost.com/llms.txt

Use this file to discover all available pages before exploring further.

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Real-time events

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Why a separate WebSocket endpoint

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Connecting

import { io } from 'socket.io-client';

const socket = io('https://ws.tensorcost.com', {
  path: '/ws',
  auth: {
    token: 'YOUR_JWT',          // Cognito ID token or backend-issued HS256
    activeTenantId: 'tenant-...' // optional: for users with multi-tenant access
  },
  transports: ['websocket', 'polling'],
});

socket.on('event', (event) => {
  console.log(event.type, event.data);
});

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Authentication

• Cognito (RS256) — verified against the user pool’s JWKS. Resolved to a user via cognito_sub; tenant membership joins the socket to the right room.
• Backend-issued (HS256) — verified against the shared secret; tenantId (or tenant_id) embedded directly.

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Event envelope

{
  "type": "ml.training.completed",
  "data": {
    "model_type": "gpu_anomaly",
    "duration_ms": 7512,
    "model_id": 42
  },
  "timestamp": "2026-04-29T16:41:38.412Z",
  "trace_id": "7a0db7e045..."
}

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Event catalog

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Using events in a React app

const PREFIX_TAG_MAP: Record<string, string[]> = {
  'instance.':       ['instance'],
  'metrics.':        ['metric'],
  'cost.':           ['cost'],
  'alert.':          ['alert'],
  'recommendation.': ['recommendation'],
  'runaway_loop.':   ['agent', 'recommendation'],
  'ml.':             ['ml-model'],
};

socket.on('event', (e) => {
  const tags = tagsForEvent(e.type);
  if (tags) queryClient.invalidateQueries({ queryKey: tags });
});

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Reliability guarantees

• In-process priority. Events dispatch to local subscribers synchronously in the publish path with no Redis dependency. A single-instance deployment works end-to-end with no broker.
• Redis for durability (when configured). Events are also LPUSH’d onto per-type queues for cross-instance replay. A bounded LRU of recently-dispatched event IDs prevents double delivery.
• Best-effort on Redis failure. If Redis is unreachable, events still reach all in-process subscribers (and thus the Socket.IO bridge). Only cross-instance replay is lost.
• Per-type ordering. Events within a single type are ordered. Across types, no ordering guarantees.
• Per-tenant rate limits. Socket.IO emit rate is capped per tenant to protect noisy-neighbor scenarios. Default 100 events/sec/tenant; raise on enterprise tier.

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Webhooks

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Debugging connection issues

• Wrong hostname. If the socket points at api.tensorcost.com, the upgrade is rejected. Verify VITE_WS_URL (or your env-equivalent) targets ws.tensorcost.com.
• Certificate SAN mismatch. A new WS subdomain must be in the ALB cert’s SAN list. Reissue ACM if you added one.
• Expired JWT. Sockets don’t auto-refresh tokens. After ~1 hour, reconnect with a fresh token. The dashboard handles this automatically on route navigation.
• CORS origin. The backend’s CORS_ORIGIN must include the frontend origin.

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MCP

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Tool surface

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Scope-guarded by RBAC

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Authenticating

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Use cases

• CFO / finance — point Claude Desktop at TensorCost MCP and ask “what drove last week’s Bedrock bill?” The model uses cost.summary + inference.recommendations to compose the answer.
• Platform engineer — wire your internal agent to MCP to assert budgets and pause runaway agents during incidents.
• Partner integration — build a Datadog / Grafana panel that consumes cost.summary and connections.health for embedded TensorCost views.