Ansiclaw

ANSIClaw 🦞🎨

Draw ANSI art via the local Clawbius REST API. Depends on Clawbius (https://github.com/n2tr0n/clawbius) running locally on port 7777. Also depends on python 'requests'. Optimized for Mac OS Sequoia.

⛔ HARD RULES — READ BEFORE ANYTHING ELSE

1. NEVER modify reference files. Files in resources/ are your source material. Do not open them via /api/file/open without immediately calling /api/file/new afterward to switch to a fresh canvas. Opening a file in Clawbius makes it the active canvas — any draw calls will corrupt it. Analyze reference files by reading canvas data ONLY, then immediately create a new canvas before drawing.

2. NEVER save or export over an existing ANS file without operators explicit instruction. Always use a new versioned filename (e.g. flower_v2.ans).

3. NEVER use /api/file/export-png — the correct endpoint is /api/file/export/png (with a slash before png).

1. Session Start Checklist

Every new ANSIClaw session, in order:

1. GET http://127.0.0.1:7777/api/canvas/info — confirm Clawbius is running
   • If not running it can be started from the clawbius folder with: launch_clawbius.sh
2. GET http://127.0.0.1:7777/api/openapi.json — check for API changes
3. Study reference files (see Section 3 below) — mandatory before drawing
4. Read references/api.md for full endpoint details
5. Check that ice colors are set to OFF unless Operator says otherwise (see Section 2 below)

Output dir: the 'outputs' folder in your skill folder — save ANS + PNG here - create the folder if it is not there

2. Color Rules

⚠️ ICE COLORS — DEFAULT IS OFF. THIS IS CRITICAL.

Ice colors are OFF by default. Do not use colors 8–15 as background colors unless Operator explicitly says "ice colors on" or "this is an ice colors ANSI".

• Colors 0–7 are always safe as background
• Colors 8–15 as background only when ICE colors are specified ON by the Operator - this is a special mode not commonly used

When Operator says "ice colors on":

• Call POST /api/ui/ice-colors {"value": true}
• Also pass "ice_colors": true in your POST /api/file/new call
• Now bg colors 8–15 are available and open up new dithering possibilities

16-Color Palette

DARK (safe as bg):
  0=black       1=dark blue   2=dark green  3=dark cyan
  4=dark red    5=magenta     6=brown       7=light gray

BRIGHT (fg only unless ice colors on):
  8=dark gray   9=blue        10=green      11=cyan
  12=red        13=light mag  14=yellow     15=white

Shade Blocks (F1–F4)

F1=176 ░  light shade    F2=177 ▒  medium shade
F3=178 ▓  dark shade     F4=219 █  full block

Dithering is achieved by varying the shade block (F1–F4) with different fg/bg color pairs. This is the primary tool for gradients, texture, and depth — not solid color fills.

Half-Blocks useful for edges and, smoother curves and anti-aliasing techniques

220=▄ lower half   223=▀ upper half
221=▌ left half    222=▐ right half

3. Studying Reference Files (MANDATORY)

Before drawing anything, study the reference files in resources/. Do all three steps:

• load the file in Clawbius - inspect it with the API
• take a screenshot with peekaboo and analyze the image (if peekaboo is there)

Learn style and shading techniques from the provided examples and use them, especially dither, half block, no tocar techniques (disparate objects being separated by a half block of blackspace) and the effective use of black/negative space and falloff shading and gradients.

Step 1 — Read the README

resources/README.md

Get the description of each file and what it demonstrates.

Step 2 — Open and analyze canvas data via API

import requests, json
# Open the reference file
requests.post("http://127.0.0.1:7777/api/file/open",
    json={"path": "/absolute/path/to/resources/file.ans"})

# Get canvas info
info = requests.get("http://127.0.0.1:7777/api/canvas/info").json()

# Get full canvas data and analyze color/code usage
data = requests.get("http://127.0.0.1:7777/api/canvas/data").json()
blocks = data["result"]
cols = info["result"]["columns"]

# Study a region (e.g. rows 10-20):
for y in range(10, 20):
    unique = {}
    for x in range(0, cols):
        b = blocks[y * cols + x]
        key = (b["code"], b["fg"], b["bg"])
        unique[key] = unique.get(key, 0) + 1
    top = sorted(unique.items(), key=lambda x: -x[1])[:6]
    print(f"row {y}: {top}")

Look for:

• What fg/bg color pairs dominate each region?
• Which shade blocks (F1–F4) are used and where?
• How are transitions handled between regions?
• What bg colors are used — are they all 0–7?

Step 3 — Analyze the reference PNG

Each reference file in resources/ should have a matching .png alongside the .ans file. Use the image tool to analyze the PNG directly:

image(image="<absolute_path_to_resources/file.png>", prompt="...")

Study:

• Color regions and how they transition
• Where black separators appear between colored areas
• Half-block usage on edges and curves
• Overall composition and density

4. Core Style Rules

No-Tocars (Colored Areas Must Not Touch)

This is an important stylistic rule of some ANSI art.

Colored areas of different objects can look more appealing when not touching each other directly. They can be separated by black (fg or bg=0) half-blocks or full blocks. This gives the art a clean, distinct look.

Wrong: Red block directly adjacent to yellow block Right: Red block → black half-block separator → yellow block

Use ▌(221), ▐(222), ▀(223), ▄(220) with fg=color, bg=BLACK to create clean color boundaries.

Example — transitioning from red to yellow area:

[RED F4][▐ fg=RED bg=BLACK][▌ fg=YELLOW bg=BLACK][YELLOW F4]

Shading & Depth

• Use F1–F4 shade blocks to build gradients — never just solid color fills for large areas
• Light source: decide where the light is coming from and be consistent
• Lit faces: use lighter shade blocks (F1/F2) or higher-contrast fg color
• Shadow faces: use F3/F4 or black fg
• Edges catch light: use UH(223) or LH(220) with bright fg on dark bg for edge highlights

Typical Shading Patterns

Sky gradient (top to bottom, dark to light):
  F4 fg=DBLUE bg=BLACK → F3 fg=BLUE bg=BLACK → F2 fg=BLUE bg=BLACK → F1 fg=CYAN bg=BLACK

Ground (dark):
  F4 fg=BLACK bg=BLACK → F3 fg=BROWN bg=BLACK → F2 fg=BROWN bg=BLACK

Metal object (gray, lit from top-left):
  top edge:  UH fg=LGRAY bg=DGRAY  ← highlight
  upper:     F2 fg=LGRAY bg=DGRAY
  mid:       F3 fg=DGRAY bg=BLACK
  lower:     F4 fg=BLACK bg=BLACK  ← deep shadow

Fire/explosion background:
  F3 fg=RED bg=BLACK → F2 fg=BROWN bg=BLACK → F1 fg=YELLOW bg=BLACK
  Vary randomly across rows/columns — avoid horizontal banding

General style tip: Once the gradient is established, add complexity - patterns can be mixed up to create interesting textures.

Half-Block Edge Technique

At the boundary between a filled area and black space, use half-blocks to smooth the edge and add depth:

• UH(223) fg=color bg=BLACK — object color on top, black below (bottom edge of object)
• LH(220) fg=color bg=BLACK — black on top, object color below (top edge of object)
• These also double as separators (no-tocars) between two color regions
• Also use half blocks for round, circular edges and diagonal lines and organic shapes like hair or body curves

5. Drawing Approach

Write Python scripts using requests. Never curl individual cells — always batch with scripts.

Script template:

import requests, os
BASE = "http://127.0.0.1:7777"

def post(path, data):
    r = requests.post(f"{BASE}{path}", json=data)
    resp = r.json()
    if not resp.get("ok"): print(f"WARN {path}: {resp}")
    return resp

def rect(x, y, w, h, code=219, fg=7, bg=0):
    if w > 0 and h > 0:
        post("/api/draw/rect/filled", {"x":x,"y":y,"width":w,"height":h,"code":code,"fg":fg,"bg":bg})

def at(x, y, code=219, fg=7, bg=0):
    post("/api/draw/at", {"x":x,"y":y,"code":code,"fg":fg,"bg":bg})

def line(x1, y1, x2, y2, code=219, fg=7, bg=0):
    post("/api/draw/line", {"x1":x1,"y1":y1,"x2":x2,"y2":y2,"code":code,"fg":fg,"bg":bg})

# Canvas setup — ice_colors=False unless Operator says otherwise
post("/api/file/new", {
    "columns": 80, "rows": 25,
    "title": "Title", "author": "Clawd", "group": "ANSIClaw",
    "ice_colors": False
})

Save scripts to skill folder scripts/ Save output to skill folder output/ — always export both ANS and PNG.

6. Input Files (Image-to-ANSI Renditions)

Operator may drop a source image into inputs/ and ask for an ANSI rendition of it. Do not check this folder unless explicitly asked.

When asked to render an input file:

1. Read the image with the image tool — study shapes, dominant colors, light source, and composition
2. Map the image's colors to the 16-color ANSI palette (find the closest match for each major region)
3. Plan the canvas layout — decide which regions become which shade/color blocks
4. Simplify aggressively — ANSI art is abstraction, not photorealism. Pick 3-5 dominant colors max
5. Sketch the composition in comments before coding: major regions, where half-blocks go, light direction
6. Draw it — apply all the usual style rules (no-tocars, shade gradients, half-block edges)
7. Save output to the usual place

7. Full API Reference

See references/api.md — full endpoint details, parameter lists, CP437 extended codes.

8. Lessons Learned (from real sessions)

Sky / Background Gradients

• Don't use random noise for texture — even at 15-18% density it creates "rain" or "static" artifacts that look terrible.
• Don't use per-column checkerboard dithering on every row — ANSI cells are tall and narrow, so alternating x%2 columns creates visible vertical stripes, not smooth blending.
• Do use clean solid bands — banding is natural and expected in ANSI art sky gradients. 4-5 rows per band (F4→F3→F2→F1, DBLUE on BLACK) reads cleanly.
• If you want a subtle transition between bands, a single dither row between solid blocks is the maximum — and even that can stripe visually, so test it.

Petals / Organic Shapes

• Start wider than you think you need. Horizontal spread reads better at ANSI cell aspect ratio than height.
• Use the full shade gradient within each petal (F1 at tip → F4 at base where it meets the center) to imply curvature.
• Each petal's outermost edge should be RFH/LFH (half-block) with bg=BLACK to keep the no-tocars boundary clean.
• Diagonal petals need extra width (4+ cols) to be visible — don't short-change them.

Centers / Small Color Areas

• A 2x2 center block can convey light/shadow convincingly:
  • top-left: F1 bright-color on dark-bg (lit)
  • top-right: F2
  • bottom-left: F3
  • bottom-right: F4 (deepest shadow)
• bg=BROWN (6) is always safe (it's <8), good for warm center tones.

API Gotchas

• Export PNG endpoint is /api/file/export/png (not /api/file/export-png).
• Always check openapi.json at session start — endpoints may have changed.
• post() should print warnings but not crash on bad responses — wrap defensively.