Fill a nonce gap by sending a minimal STX transfer at the specified nonce. LAST-RESORT recovery action. Each gap-fill is a real on-chain transaction with a real fee (~0.001-0.01 STX). Most gaps self-resolve within seconds as Stacks blocks are 3-5s. Only use this after confirming the gap persists...
Part of the Aibtc MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents use nonce_fill_gap to create or modify resources in Aibtc. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call nonce_fill_gap repeatedly, creating or modifying resources faster than any human could review. Intercept's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Aibtc.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
tools:
nonce_fill_gap:
rules:
- action: allow
rate_limit:
max: 30
window: 60See the full Aibtc policy for all 308 tools.
Agents calling write-class tools like nonce_fill_gap have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Write risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.
Fill a nonce gap by sending a minimal STX transfer at the specified nonce. LAST-RESORT recovery action. Each gap-fill is a real on-chain transaction with a real fee (~0.001-0.01 STX). Most gaps self-resolve within seconds as Stacks blocks are 3-5s. Only use this after confirming the gap persists via nonce_health. When transactions are pending but a gap exists in the nonce sequence (e.g., nonces 5 and 7 are pending but 6 is missing), the Stacks mempool will not process nonces 7+ until 6 is filled. This tool fills the gap with a 1 micro-STX transfer to the PoX burn address. Use nonce_health first to identify gaps, then call this tool for each missing nonce. Requires the wallet to be unlocked. The fee is auto-estimated.. It is categorised as a Write tool in the Aibtc MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Add a rule in your Intercept YAML policy under the tools section for nonce_fill_gap. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Aibtc MCP server.
nonce_fill_gap 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 nonce_fill_gap rule in your Intercept 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 Intercept policy for nonce_fill_gap. 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.
nonce_fill_gap is provided by the Aibtc MCP server (@aibtc/mcp-server). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic policy on every MCP tool call. Per-identity grants. Full audit log.