claim_file

SERVERMeridian SOURCE@meridianmcp/mcp

Medium RISK CLASS

Category Write

Parameters 52 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-ajc3xc-meridian/claim-file.md

WHAT IT DOES

What claim_file does on Meridian

AI agents use claim_file to create or update resources in Meridian, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Meridian environment.

Parameter	Type	Required	Description
`mode`	string	—	Claim grain (ffa03655). 'write' (default) = EXCLUSIVE: blocks other writers and is blocked by any other session's read claim. 'read' = SHARED: many sessions can
`symbol`	string	—	Optional symbol to claim (class/function/method name, e.g. 'AuthRouter' or 'AuthRouter.login'). Requires `content`.
`content`	string	—	Full source of the file, required when `symbol` is given so the server can resolve the symbol's line range.
`file_path`	string	Yes
`session_id`	string	Yes

Parameters from the server's own tool schema.

RISK

Why claim_file is rated Medium

This tool establishes a lock/ownership record for a file or symbol range, which is a write operation to the coordination/locking state. It does not execute code or delete data, but it modifies session metadata and can block other sessions from editing — a reversible side effect (auto-expires after 2 hours). Misuse could cause edit conflicts or lock out legitimate sessions, giving it medium severity.

From the tool's definition 'Claim edit rights on a file for this session' and 'hard-blocks if another live session already owns an overlapping line range'

Risk signalsAccepts file system path (file_path) · Accepts raw HTML/template content (content)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs claim_file safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Meridian, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For claim_file, this is the rule to start with:

claim_file Rate-limited

claim_file 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "claim_file": {
      "limits": [
        {
          "counter": "claim_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Meridian, apply this rule, and every claim_file call is checked against it from then on.

FAQ

Questions about claim_file

What does the claim_file tool do? +

[SUPPORT] Claim edit rights on a file for this session. Whole-file by default (auto-expires after 2 hours). For symbol-level claims — so two sessions can edit the same file if they own different classes/functions — also pass symbol (e.g. 'AuthRouter' or 'AuthRouter.login') AND content (the file's full source). Meridian parses the source (stdlib ast for Python, tree-sitter for JS/TS/C/C++/Go/Rust/Java/C#), and hard-blocks if another live session already owns an overlapping line range — the block lists which symbols are still safe to claim. Unparseable content falls back to a whole-file lock. The response includes a code_notes list of code-anchored project notes (kind='code') for this file/symbol — read them before editing. Persistent-state disclosure: on hosted Meridian, supplied text and project/session metadata are sent to and stored in Meridian's service; self-hosted deployments keep them in the configured local SQLite/Postgres database. This data is visible in the dashboard/API and later project context or handoffs. Delete individual tasks, notes, or decisions where supported, or delete the project/account using the documented controls. Do not include secrets. It is categorised as a Write tool in the Meridian MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does claim_file accept? +

claim_file accepts 5 parameters: mode, symbol, content, file_path, session_id. Required: file_path, session_id. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on claim_file? +

Register the Meridian MCP server in PolicyLayer and add a rule for claim_file: 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 Meridian. Nothing to install.

What risk level is claim_file? +

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

Can I rate-limit claim_file? +

Yes. Add a rate_limit block to the claim_file 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.

How do I block claim_file completely? +

Set action: deny in the PolicyLayer policy for claim_file. 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 claim_file? +

claim_file is provided by the Meridian MCP server (@meridianmcp/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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