Image Studio

What the source does

• FilesystemDeclared5 observations
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

assistant/CLAUDE.md

assistant/src/approvals/CLAUDE.md

assistant/src/notifications/CLAUDE.md

assistant/src/runtime/CLAUDE.md

gateway/CLAUDE.md

} from "../../../../media/image-credentials.js";

import { resolveRequestedImageModel } from "../../../../media/image-models.js";

} from "../../../../media/image-service.js";

import { getFilePathBySourcePath } from "../../../../persistence/attachments-store.js";

import type { ImageContent } from "../../../../providers/types.js";

Audit 0.4.1 · source sha 19bc86343b63 · 14 Oct 2026Report an issue or request a re-scan

• Publishervellum-ai GitHub organizationOwner of the repository this skill is read from
• Source foldervellum-ai/vellum-assistant/assistant/src/config/bundled-skills/image-studioThe exact folder we audited
• LicenceMITAs the repository states it
• Commit pinned for this verdict19bc86343b63A new audit runs when the source changes
• Repository statusNot archivedLast push 1 day ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Create images from a text description, or edit photos and graphics the user provides (remove backgrounds or watermarks, retouch, restyle, in-paint). Can produce multiple variants when the user wants options to choose…

---
name: image-studio
description: Create images from a text description, or edit photos and graphics the user provides (remove backgrounds or watermarks, retouch, restyle, in-paint). Can produce multiple variants when the user wants options to choose from.
compatibility: "Designed for Vellum personal assistants"
metadata:
  emoji: "🎨"
  vellum:
    display-name: "Image Studio"
    category: "content"
    activation-hints:
      - "User asks to generate, draw, or create an image from a text prompt"
      - "User wants to edit an existing image: background removal, watermark removal, in-painting, style change, retouching"
      - "User wants multiple variations of a visual (logo concepts, mood boards, illustration options)"
---

Use the `media_generate_image` tool via `skill_execute` to create or edit images.

## Modes

- **generate** (default): Create a new image from a text prompt.
- **edit**: Modify an existing image. Requires one or more source images via `source_paths`.

## Models

Do not pass the `model` parameter unless you need a specific tier. Omitting it uses the configured default, which is correct for most requests.

When you do need to choose, use an alias, not a concrete model ID. Aliases always resolve to the current model for that tier:

- `fast`: quickest, good quality (default tier)
- `quality`: higher fidelity, slower
- `openai`: OpenAI's model; most permissive on photo edits

Pass a concrete model ID only if the user names one explicitly. If the tool rejects an unknown model ID, the error lists the currently available models and aliases.

## Example calls

Generate (no model parameter, default is correct):

```json
{
  "tool": "media_generate_image",
  "input": {
    "prompt": "A sunset over the ocean, golden hour, soft haze, 35mm photo style",
    "variants": 2
  }
}
```

Edit:

```json
{
  "tool": "media_generate_image",
  "input": {
    "prompt": "Remove the watermark text from the background. Keep the subject, framing, lighting, and colors exactly identical. Change nothing else.",
    "mode": "edit",
    "source_paths": ["conversations/<conv-id>/attachments/photo.jpeg"],
    "model": "openai"
  }
}
```

`source_paths` is a flat array of file path strings. Do NOT pass objects:

- Wrong: `"source_paths": [{ "path": "img.jpeg" }]` → schema validation error
- Right: `"source_paths": ["img.jpeg"]`

## Source images for edit mode

- Paths resolve inside the workspace. Conversation attachments live under `conversations/<conversation-id>/attachments/`; prefer that path for images the user attached.
- Host paths (e.g. `~/Desktop/photo.jpg`) only work if the file arrived as an attachment; the tool falls back to the stored workspace copy. If the user references a host file that was never attached, pull it into the workspace first, then pass the workspace path.

## Prompting

- Generate: describe style, composition, lighting, and mood, not just the subject.
- Edit: name the change AND what must stay the same. Models re-render the whole image, so without preservation language ("keep subject, framing, and lighting identical; only change X") they drift on crop and color.
- Aspect ratio and size have no parameter today. State them in the prompt ("16:9 widescreen banner") and verify the output.
- Use `variants` (1 to 4) when the user wants options. In **edit mode always use `variants: 1`**: edits run 60-90 seconds per variant, and two variants can exceed the tool execution timeout (`timeouts.toolExecutionTimeoutSec`, default 120s). If the user wants multiple edit options, make separate sequential calls.

## Timing

Edits on large photos are slow (1 to 2 minutes). If the tool reports a timeout ("timed out after Ns"), the result is lost; do not wait for it to appear. Retry with `variants: 1`, or if it already was 1, fall back to the CLI which writes files to disk: `assistant image-generation generate --prompt "..." --mode edit --source <path> --model openai --output-dir <dir>`.

## Output handling

Each generated image is saved into the workspace under `media/generated/` and the tool result lists the saved paths. The images also come back as inline content blocks so you can judge the result before presenting it.

- Present an image to the user by embedding its saved path in your reply: `![short description](vellum://workspace/media/generated/<file>.png)`. The app renders it inline where your text refers to it, and chat channels (Slack, Telegram, WhatsApp) deliver it as a native image upload.
- Label a plain image link "View image", for example `[View image](vellum://workspace/media/generated/<file>.png)`. The link opens a preview; do not call it "Download" or promise a download in the surrounding text. To save the image, the user can choose Download in the preview.
- If you do not embed it, the image is still auto-attached to your reply as a file, so it is never lost. Prefer embedding: an attachment chip at the end of the message is a worse presentation than the image inline.
- To iterate on a result, pass its saved path via `source_paths` with `mode: "edit"`.

## Error handling

Two kinds of failure. Treat them differently:

1. **Configuration errors** (missing API key, provider not set up): report the error to the user as-is. Do NOT change service configuration (managed vs your-own mode, default provider, or default model in Settings). Configuration changes happen only at the user's explicit request.
2. **Generation failures** (any other error: "invalid", content policy, safety rejection, provider error). Do not diagnose the cause; switch providers. The error message names the model that failed:
   - If the error names a `gemini-*` model (or no model) → retry ONCE with `model: "openai"`.
   - If the error names `gpt-image-2` or another `gpt-*` model → retry ONCE with `model: "quality"`.
   - If the retry also fails → stop and report both errors to the user.

Do NOT rephrase the prompt and retry on the same model, even if the error suggests checking the prompt. One provider switch,

Excerpt, first 6,001 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/vellum-ai/vellum-assistant
git -C vellum-assistant checkout 19bc86343b63

Works in

1. 2026-10-14
   ✓SAFE B 89 / 100

   first audit · source 19bc86343b63

Questions about Image Studio

• github.com/vellum-ai/vellum-assistant/tree/main/assistant/src/co — the audited source at commit 19bc86343b63 and every finding aboveObserved · 14 Oct 2026

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