Bug: Session permanent lockup on "Invalid Request" (non-ASCII base64)

[juanpujol]

Description

I'm hitting a loop where a 400 Bad Request from the Anthropic API completely bricks a Crush session.

The Bug: When using the playwriter MCP, it sometimes returns image data with non-ASCII characters in the base64 string. Anthropic rejects this immediately.

The problem is that Crush persists this "bad" message in the context. Since it stays in the history, every single message I send after that (even just saying "continue") triggers the same 400 error. I have to kill the session and start over to fix it.

Error Details

{"type":"error","error":{"type":"invalid_request_error","message":"messages.178.content.0.tool_result.content.0.image.source.base64: string argument should contain only ASCII characters"}}

It would be great if we could have a way to manage the session history—maybe a /undo or /delete command to drop the last message so we can recover from API errors like this without losing the whole session.

Version

v0.30.3

Environment

tmux

[alexanderaeppli]

I have the same issue with Figma MCP when the layout contains an image.

[Cthululz]

Same thing happens to me. Anytime a tool fails for any reason the whole session is no longer usable because every prompt afterward results in immediate errors.

[meowgorithm]

Appreciate you flagging this — it sucks and we'll fix!

[meowgorithm]

For those encountering this issue: a session log would help expedite a fix for this. The last session can be exported with crush session last --json > session.json.

(For more on exporting sessions see crush session --help).

[alexanderaeppli]

Im running MacOS 26.3 on a MacBook Pro M1 and crush version v0.56.0.
I remember this used to work before but i'm not 100% certain.

Session JSON

{
  "meta": {
    "id": "3a00120846e8297e",
    "uuid": "f1285c83-bacf-48d2-876f-2ccb2d902fd4",
    "title": "Figma Design to Twig Template",
    "created": "2026-04-10T09:16:44+02:00",
    "modified": "2026-04-10T09:17:06+02:00",
    "cost": 0.20451875,
    "prompt_tokens": 26107,
    "completion_tokens": 44,
    "total_tokens": 26151
  },
  "messages": [
    {
      "id": "ab753ee7-8eab-475b-8e20-cf60a46256eb",
      "role": "user",
      "created": "2026-04-10T09:16:44+02:00",
      "parts": [
        {
          "type": "text",
          "text": "implement my figma selection as a twig template"
        },
        {
          "type": "finish",
          "reason": "stop"
        }
      ]
    },
    {
      "id": "507b1911-31ab-41ff-8248-e0b78d6fe227",
      "role": "assistant",
      "created": "2026-04-10T09:16:44+02:00",
      "model": "claude-opus-4-6",
      "provider": "anthropic",
      "parts": [
        {
          "type": "reasoning",
          "thinking": "Let me get the Figma design context first.",
          "started_at": 1775805407,
          "finished_at": 1775805408
        },
        {
          "type": "tool_call",
          "tool_call_id": "toolu_01KYHZuVTvFYQHzB6FfhBEmZ",
          "name": "mcp_figma-desktop_get_design_context",
          "input": "{\"clientLanguages\": \"html,css,scss,php\", \"clientFrameworks\": \"twig,timber,wordpress,elementor\", \"artifactType\": \"COMPONENT_WITHIN_A_WEB_PAGE_OR_APP_SCREEN\", \"taskType\": \"CREATE_ARTIFACT\"}"
        },
        {
          "type": "finish",
          "reason": "tool_use",
          "time": 1775805414
        }
      ]
    },
    {
      "id": "bbcced50-ffad-4394-bf34-6d6b4edfb71e",
      "role": "tool",
      "created": "2026-04-10T09:16:54+02:00",
      "parts": [
        {
          "type": "tool_result",
          "tool_call_id": "toolu_01KYHZuVTvFYQHzB6FfhBEmZ",
          "name": "mcp_figma-desktop_get_design_context",
          "content": "Path for asset writes as tool argument is required for write-to-disk option"
        },
        {
          "type": "finish",
          "reason": "stop"
        }
      ]
    },
    {
      "id": "30297415-8b25-4ab1-893c-fa534038ee8f",
      "role": "assistant",
      "created": "2026-04-10T09:16:54+02:00",
      "model": "claude-opus-4-6",
      "provider": "anthropic",
      "parts": [
        {
          "type": "tool_call",
          "tool_call_id": "toolu_01Wuh3tsieK3nwDtRRQRvy6Y",
          "name": "mcp_figma-desktop_get_design_context",
          "input": "{\"artifactType\": \"COMPONENT_WITHIN_A_WEB_PAGE_OR_APP_SCREEN\", \"clientFrameworks\": \"twig,timber,wordpress,elementor\", \"clientLanguages\": \"html,css,scss,php\", \"taskType\": \"CREATE_ARTIFACT\", \"dirForAssetWrites\": \"/Users/alexanderaeppli/PhpstormProjects/dcwi-theme-2025/dcwi-theme/assets/images\"}"
        },
        {
          "type": "finish",
          "reason": "tool_use",
          "time": 1775805420
        }
      ]
    },
    {
      "id": "13bd55c2-ac53-4619-8411-99f68a3fa3d0",
      "role": "tool",
      "created": "2026-04-10T09:17:00+02:00",
      "parts": [
        {
          "type": "tool_result",
          "tool_call_id": "toolu_01Wuh3tsieK3nwDtRRQRvy6Y",
          "name": "mcp_figma-desktop_get_design_context",
          "content": "export default function Frame() {\n  return (\n    <div className=\"content-stretch flex items-center relative size-full\" data-node-id=\"1:8\">\n      <div className=\"bg-[#d9d9d9] h-[112px] shrink-0 w-[693px]\" data-node-id=\"1:3\" />\n      <div className=\"bg-[#ba0808] shrink-0 size-[112px]\" data-node-id=\"1:6\" />\n    </div>\n  );\n}\nSUPER CRITICAL: The generated React+Tailwind code MUST be converted to match the target project's technology stack and styling system.\n1. Analyze the target codebase to identify: technology stack, styling approach, component patterns, and design tokens\n2. Convert React syntax to the target framework/library\n3. Transform all Tailwind classes to the target styling system while preserving exact visual design\n4. Follow the project's existing patterns and conventions\nDO NOT install any Tailwind as a dependency unless the user instructs you to do so.\n\nNode ids have been added to the code as data attributes, e.g. `data-node-id=\"1:2\"`.\nImage assets should be read from disk. Images and SVGs will be stored as constants, e.g. const image = '/Users/alexanderaeppli/PhpstormProjects/dcwi-theme-2025/dcwi-theme/assets/images/10c13ac1a228a365cb98a0064b1d5afbc84887b2.png' These constants will be used in the code as the source for the image, e.g. <img src={image} /> This is true for both images and SVGs, so you can use the same approach for both types of assets.\nIMPORTANT: After you call this tool, you MUST call get_screenshot to get a screenshot of the node for context."
        },
        {
          "type": "finish",
          "reason": "stop"
        }
      ]
    },
    {
      "id": "2a6cb99a-ff79-4dee-a9eb-349bd4f5e89a",
      "role": "assistant",
      "created": "2026-04-10T09:17:00+02:00",
      "model": "claude-opus-4-6",
      "provider": "anthropic",
      "parts": [
        {
          "type": "tool_call",
          "tool_call_id": "toolu_012ZR9XSB4ALiMEv4EHiwkEy",
          "name": "mcp_figma-desktop_get_screenshot",
          "input": "{}"
        },
        {
          "type": "finish",
          "reason": "tool_use",
          "time": 1775805426
        }
      ]
    },
    {
      "id": "12815468-76e6-4019-92d7-a6f6bca7c5f5",
      "role": "tool",
      "created": "2026-04-10T09:17:06+02:00",
      "parts": [
        {
          "type": "tool_result",
          "tool_call_id": "toolu_012ZR9XSB4ALiMEv4EHiwkEy",
          "name": "mcp_figma-desktop_get_screenshot",
          "content": "Loaded image/png content",
          "mime_type": "image/png"
        },
        {
          "type": "finish",
          "reason": "stop"
        }
      ]
    },
    {
      "id": "96cdfaef-b347-4c1b-ad97-3f7585d7766c",
      "role": "assistant",
      "created": "2026-04-10T09:17:06+02:00",
      "model": "claude-opus-4-6",
      "provider": "anthropic",
      "parts": [
        {
          "type": "finish",
          "reason": "error",
          "time": 1775805426
        }
      ]
    }
  ]
}

Crush Log

2026/04/10 09:16:35 INFO Initializing MCP clients source=github.com/charmbracelet/crush/internal/agent/tools/mcp/init.go:167
2026/04/10 09:17:06 ERRO Error reported error="bad request: POST \"https://api.anthropic.com/v1/messages\": 400 Bad Request (Request-ID: req_011CZugU4W8sd3bznMVsfrC7) {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"Could not process image\"},\"request_id\":\"req_011CZugU4W8sd3bznMVsfrC7\"}" source=github.com/charmbracelet/crush/internal/ui/model/ui.go:841

[meowgorithm]

@alexanderaeppli Thank you! Please also try out #2597 which should hopefully fix this.

That said, we'll analyze it against your session. Thank you!

[meowgorithm]

This should be fixed on main and will be available in the next release. That said, please let us know if you still encounter the issue (and let us know the Crush version).

Also note that we were indeed able to verify the behavior from the above session. Thank you!