Medium Risk

nonce_fill_gap

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.

@aibtc/mcp-server Write Risk 2/5

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.

io-github-aibtcdev-mcp-server.yaml
tools:
  nonce_fill_gap:
    rules:
      - action: allow
        rate_limit:
          max: 30
          window: 60

See the full Aibtc policy for all 288 tools.

Tool Name nonce_fill_gap
Category Write
MCP Server Aibtc MCP Server
Risk Level Medium

View all 288 tools →

What does the nonce_fill_gap tool do? +

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.

How do I enforce a policy on nonce_fill_gap? +

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.

What risk level is nonce_fill_gap? +

nonce_fill_gap is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit nonce_fill_gap? +

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.

How do I block nonce_fill_gap completely? +

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.

What MCP server provides nonce_fill_gap? +

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.

Enforce policies on Aibtc

Open source. One binary. Zero dependencies.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.