truth layer for agents

The canonical data layer for the APIs & tools AI agents call.

LLMs go stale. Schemas drift. Agents don't error — they silently make valid-but-wrong calls. canondb tracks the current schema and classifies every breaking change, so agents call the truth.

Explore the free API Use the MCP server
8 sources tracked 7 MCP servers refreshed every 6h classified by LLM

One feed. Classified.

We pre-track a curated set of the tools agents actually call, normalize every schema, and do the thing raw changelogs don't: say who a change breaks.

Always current

Each source is re-fetched on a schedule. Every response carries fetched_at and a stale flag — we never serve stale data as current.

Breaking for whom?

Each change is classified, not just detected.

breaking_strict breaking_agent safe

API · MCP · feed

Query it over REST, let agents consult it at call-time over MCP, or browse the public Git feed. Same corpus, three surfaces.

Free API

Public, no key required — the current normalized schema and recent classified changes for every tracked source.

# list everything we track
curl https://canondb.dev/sources

# current schema for a source (+ fetched_at, stale)
curl https://canondb.dev/sources/mcp-tools:deepwiki/current

# recent breaking changes
curl "https://canondb.dev/sources/mcp-tools:deepwiki/changes?severity=breaking_strict"

MCP server — call-time, for agents

Point an agent at https://canondb.dev/mcp (Streamable HTTP). Mid-task it can ask "has this tool's schema drifted since I last synced?" before it calls.

# tools
list_sources   get_current   get_changes   check_drift

# connect (bearer-gated)
npx @modelcontextprotocol/inspector  # → https://canondb.dev/mcp

What we track

Curated, not point-it-anywhere. Want one added? Ask below.

llm-pricing:openrouter LLM pricing current · changes
mcp-tools:cloudflare-docs MCP server current · changes
mcp-tools:context7 MCP server current · changes
mcp-tools:deepwiki MCP server current · changes
mcp-tools:gitmcp MCP server current · changes
mcp-tools:grep MCP server current · changes
mcp-tools:huggingface MCP server current · changes
mcp-tools:microsoft-learn MCP server current · changes

Request a source · get breaking-change alerts

Tell us which server or API to add, or that you want a webhook when a schema breaks. This shapes what we build next.