Changelog

This page documents all notable changes to the Blocklens platform and API.

Snapshot API

SVG output is now a first-class citizen alongside PNG. The POST /v1/chart/snapshot format field accepts "png", "svg", or "json"; both GET and POST also honor Accept: image/svg+xml.
New route: GET /v1/chart/renders/{render_id}.svg — rendered SVGs are persisted for 1 hour and re-fetchable by URL, mirroring the existing .png behavior.
SVG responses now include X-Render-Id so the persistent URL can be reconstructed from a single render call.
PNG and SVG variants of the same chart are cached independently.
Cycle performance overlays (x_axis: "day_offset") now render X-axis tick labels as calendar dates from the latest cycle of the chosen family (e.g. Oct '25, Jan '26, … for ATH overlays anchored at cycle_ath_5 → 2025-10-06) instead of Day 0, Day 90, … . Earlier cycles remain aligned on the same axis positions.

MCP Server

render_chart: the format parameter enum is now "png" | "svg" | "json" (was "png" | "json"). When format: "svg" is passed, the tool returns an image/svg+xml content block and a /chart/renders/{id}.svg URL in the summary.

Metrics & API

Metric count expanded from 127 to 210+ active metrics (exchanges, derivatives, DAT, and more).
New endpoint: GET /v1/cycle-boundaries — Bitcoin halving cycle start/end dates and durations.
Metrics API now uses a registry-driven query builder for consistent response formatting.

Snapshot API

Heatmap rendering: render distribution-based charts (e.g., Cost Basis Distribution) with configurable color scales (viridis, plasma, etc.) and Y-axis scales. Includes color scale legend.
Cycle performance overlay charts: x_axis: "day_offset" aligns all halving cycles to Day 0 for comparison.
New per-metric parameter: show_in_legend — control whether individual metrics appear in the chart legend.

MCP Server

New tool: get_cycle_boundaries — query halving cycle dates directly from AI agents.
render_chart now supports heatmap rendering and cycle performance overlays.
Unified TypeScript codebase (tools.ts) for all MCP tools.
Tool count: 18 → 19.