moeru-ai/airi · error · ActionError

UNKNOWN

UNKNOWN

Error message

Block type mismatch at ${pos}: expected ${expected_block_type}, got ${block.name}

What it means

Thrown by the mineBlockAt action (ActionError code UNKNOWN) when expected_block_type is supplied, the block exists at pos, but matchesBlockAlias(expected_block_type, block.name) returns false. This is a deliberate safety check so the bot does not break the wrong block. Context carries { position, expected, actual }.

Source

Thrown at integrations/minecraft/src/cognitive/action/llm-actions.ts:296

    // NOTICE: detach auto-follow before mining (same reason as collectBlocks) so the follow reflex
    // cannot interrupt bot.dig mid-break.
    followControl: 'detach',
    schema: z.object({
      x: z.number().describe('The x coordinate.'),
      y: z.number().describe('The y coordinate.'),
      z: z.number().describe('The z coordinate.'),
      expected_block_type: z.string().optional().describe('Optional: expected block type at the position (e.g. oak_log). If provided and mismatched, the action fails.'),
    }),
    perform: mineflayer => async (x: number, y: number, z: number, expected_block_type?: string) => {
      const pos = new Vec3(Math.floor(x), Math.floor(y), Math.floor(z))
      if (expected_block_type) {
        const block = mineflayer.bot.blockAt(pos)
        if (!block) {
          throw new ActionError('TARGET_NOT_FOUND', `No block found at ${pos}`, { position: pos })
        }

        if (!matchesBlockAlias(expected_block_type, block.name)) {
          throw new ActionError('UNKNOWN', `Block type mismatch at ${pos}: expected ${expected_block_type}, got ${block.name}`, {
            position: pos,
            expected: expected_block_type,
            actual: block.name,
          })
        }
      }

      await breakBlockAt(mineflayer, pos.x, pos.y, pos.z)
      return `Mined block at (${pos.x}, ${pos.y}, ${pos.z})`
    },
  },
  {
    name: 'craftRecipe',
    description: 'Craft an item. Automatically finds or places a crafting table if needed, and handles intermediate materials for basic items (planks, sticks). Use recipePlan first to check required materials for complex items.',
    execution: 'async',
    schema: z.object({
      recipe_name: z.string().describe('The name of the output item to craft.'),
      num: z.number().int().describe('The number of times to execute the recipe (craft count, NOT output item count). E.g. crafting planks once yields 4 planks, so num=2 yields 8 planks.').min(1),

View on GitHub (pinned to 27111382b4)

Solutions

Re-scan the area to get fresh block names before retrying with corrected coordinates.
Use a broader alias or the exact minecraft block name returned in 'actual' from the context.
If the block was already removed, treat the task as complete rather than retrying.
Omit expected_block_type to skip the check entirely when the position is trusted.

Defensive patterns

Strategy: try-catch

Validate before calling

const block = bot.blockAt(pos)
if (expected_block_type && block && !matchesBlockAlias(expected_block_type, block.name))
  // re-scan or correct expected_block_type before mining

Type guard

function blockMatchesExpectation(bot, pos, expected) {
  const block = bot.blockAt(pos)
  return !expected || !block || matchesBlockAlias(expected, block.name)
}

Try / catch

try {
  await performAction({ tool: 'mineBlockAt', params: { x, y, z, expected_block_type } })
} catch (e) {
  if (e.code === 'UNKNOWN' && e.context?.actual)
    // use e.context.actual as the corrected type or re-scan
  throw e
}

Prevention

Re-scan block names before retrying after a mismatch.
Use the exact block name from the context 'actual' field.
Omit expected_block_type to skip the check on trusted positions.

When it happens

Trigger: The LLM/player expects 'oak_log' at a position but the actual block is 'oak_leaves' or 'air' (already mined); coordinates drifted or were rounded; the alias maps to a different family than the block present.

Common situations: The target was already mined by another player or creeper explosion; the LLM used stale coordinates from an earlier observation; alias normalization maps both directions but the actual block is genuinely different; floor() rounding landed on an adjacent block.

Related errors

AI-assisted analysis of moeru-ai/airi@27111382b4 (2026-08-12). Data as JSON: /api/errors/cdba5c19308e6638. Report an issue: GitHub.