# ── Transport ──────────────────────────────────────────────────────────
# MCP_TRANSPORT_TYPE=stdio          # stdio | http (default: stdio)
# MCP_HTTP_PORT=3010                # HTTP port (default: 3010)
# MCP_HTTP_HOST=localhost           # HTTP host (default: localhost)
# MCP_HTTP_ENDPOINT_PATH=/mcp      # HTTP endpoint path (default: /mcp)
# MCP_HTTP_MAX_BODY_BYTES=1048576  # Max request body bytes; 413 over limit, 0 disables (default: 1048576)
# MCP_PUBLIC_URL=                  # Public origin behind a TLS-terminating proxy (e.g. https://mcp.example.com)

# ── Auth ──────────────────────────────────────────────────────────────
# MCP_AUTH_MODE=none                # none | jwt | oauth (default: none)
# MCP_AUTH_SECRET_KEY=              # JWT secret (required for jwt mode)

# ── Storage ───────────────────────────────────────────────────────────
# STORAGE_PROVIDER_TYPE=in-memory   # in-memory | filesystem | supabase | cloudflare-r2 | cloudflare-kv | cloudflare-d1

# ── Session ──────────────────────────────────────────────────────────
# MCP_SESSION_MODE=stateful         # stateful | stateless (default: stateful)

# ── Memory ───────────────────────────────────────────────────────────
# MCP_GC_PRESSURE_INTERVAL_MS=0     # Opt-in forced Bun.gc(true) interval, ms (Bun only). Drains old-gen backlog
                                    # under sustained HTTP load (issue #50). Try 60000 if RSS grows. Default: 0.

# ── Logging ───────────────────────────────────────────────────────────
# MCP_LOG_LEVEL=info                # debug | info | notice | warning | error

# ── Telemetry ─────────────────────────────────────────────────────────
# OTEL_ENABLED=false                          # Enable OpenTelemetry (default: false)
# OTEL_EXPORTER_OTLP_ENDPOINT=               # OTLP endpoint URL (e.g., http://localhost:4318)

# ── Server-specific ──────────────────────────────────────────────────
# OpenAQ v3 API key — REQUIRED. Sent as the X-API-Key header on every request.
# Get a free key from your OpenAQ Explorer account: https://explore.openaq.org/
OPENAQ_API_KEY=

# OPENAQ_API_BASE_URL=https://api.openaq.org/v3   # Base URL override (testing / proxy)

# ── DataCanvas ────────────────────────────────────────────────────────
# Set to 'duckdb' to enable SQL analysis over large measurement series via
# openaq_dataframe_query / openaq_dataframe_describe. Without it, large series
# return a truncated preview and the dataframe tools are inert.
# CANVAS_PROVIDER_TYPE=duckdb