Capture the current graph shape (file/symbol counts, edges by type, top in-degree files, communities, exported symbols) under a named label. Use as a checkpoint before/after a refactor; later compare with diff_graph_snapshots. Mutates a single graph_snapshots row; idempotent (re-stamps if name ex...
AI agents use snapshot_graph to create or update resources in Trace — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Trace environment.
The tool writes/updates a snapshot record in persistent storage (graph_snapshots table). It is reversible and idempotent — re-running it just updates a timestamp — making it a Write rather than Destructive action. The blast radius is low since it only captures metadata about the graph rather than modifying source code or critical data.
From the tool's definition Mutates a single graph_snapshots row; idempotent (re-stamps if name exists). Returns JSON: { id, name, captured_at, summary }.
Documented attack patterns abuse exactly the kind of access snapshot_graph gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Trace, and nothing reaches the server without passing your rules. This is the rule we recommend for snapshot_graph:
{
"version": "1",
"default": "deny",
"tools": {
"snapshot_graph": {
"limits": [
{
"counter": "snapshot_graph_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}snapshot_graph stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Capture the current graph shape (file/symbol counts, edges by type, top in-degree files, communities, exported symbols) under a named label. Use as a checkpoint before/after a refactor; later compare with diff_graph_snapshots. Mutates a single graph_snapshots row; idempotent (re-stamps if name exists). Returns JSON: { id, name, captured_at, summary }. It is categorised as a Write tool in the Trace MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Trace MCP server in PolicyLayer and add a rule for snapshot_graph: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Trace. Nothing to install.
snapshot_graph is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the snapshot_graph rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for snapshot_graph. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
snapshot_graph is provided by the Trace MCP server (nikolai-vysotskyi/trace-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 178 Trace tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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178 Trace tools catalogued and risk-classified — across an index of 42,500+ MCP servers.