append_post_block
Append one or more blocks to the end of a post. Each block must be a valid block object: { id, version, type, data }. Types: paragraph, heading, image, list, quote, code, divider, spacer, embed, html, youtube, file, faq, callout, gallery, cta, accordion, product.
This record as markdown: /tools/io-favcrm-favcrm/append-post-block.md
What append_post_block does on FavCRM
AI agents use append_post_block to create or update resources in FavCRM, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your FavCRM environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
blocks | array | Yes | Block(s) to append |
postId | string | Yes | The post ID |
Parameters from the server's own tool schema.
Why append_post_block is rated Medium
The tool creates or modifies data (appending blocks to a post) in a reversible manner. The operation adds content without permanently destroying data, making it a Write action rather than Destructive. The severity is medium because while it modifies customer-facing content (posts), the modification is additive and can be undone by removing the appended blocks.
From the tool's definition Append one or more blocks to the end of a post. This modifies existing content by adding data to it.
Attacks that exploit this kind of access
The rule that runs append_post_block safely
PolicyLayer is an MCP gateway: it sits between your AI agents and FavCRM, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For append_post_block, this is the rule to start with:
append_post_block 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.
The button opens the PolicyLayer dashboard: create your workspace, connect FavCRM, apply this rule, and every append_post_block call is checked against it from then on.
Questions about append_post_block
Append one or more blocks to the end of a post. Each block must be a valid block object: { id, version, type, data }. Types: paragraph, heading, image, list, quote, code, divider, spacer, embed, html, youtube, file, faq, callout, gallery, cta, accordion, product. It is categorised as a Write tool in the FavCRM MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
append_post_block accepts 2 parameters: blocks, postId. Required: blocks, postId. The full parameter table on this page comes from the server's own tool schema.
Register the FavCRM MCP server in PolicyLayer and add a rule for append_post_block: 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 FavCRM. Nothing to install.
append_post_block 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 append_post_block 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 append_post_block. 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.
append_post_block is provided by the FavCRM MCP server (https://api.favcrm.io/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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