Moss Image Text To Image API Documentation

Moss Image Text To Image API Documentation

Playground

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MOSS Image Text-to-Image generates images from long text prompts, with sharp Chinese and English text rendering, 1K or 2K output and flexible aspect ratios. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

MOSS Image Text-to-Image generates images from detailed text prompts with strong support for Chinese and English text rendering. Describe the subject, composition, environment, lighting, and any text you want to appear, then choose the resolution and aspect ratio for the final image.


Why Choose This?

  • Detailed prompt understanding — Use rich scene descriptions to control composition, subject, background, lighting, and visual style.
  • Chinese and English text rendering — Create posters, signs, packaging, infographics, and other text-heavy visuals.
  • 1K and 2K output — Choose 1k or 2k depending on your quality requirements.
  • 15 aspect ratios — Generate images for a wide range of layouts and placements.
  • Multiple output formats — Export as jpeg, png, or webp.

Parameters

ParameterRequiredDescription
promptYesText description of the image to generate. Detailed prompts are recommended.
resolutionNoOutput resolution: 1k or 2k. Default: 1k.
aspect_ratioNoOutput aspect ratio. Default: 1:1.
output_formatNoOutput format: jpeg, png, or webp. Default: jpeg.
seedNoRandom seed. Use -1 for automatic random selection.

How to Use

  1. Write a prompt — Describe the subject, composition, background, lighting, and visual style. Put any text you want rendered in quotation marks.
  2. Choose a resolution — Select 1k or 2k.
  3. Choose an aspect ratio optional — Select the framing that fits your target layout.
  4. Choose an output format optional — Use jpeg, png, or webp.
  5. Set a seed optional — Use a fixed seed for repeatable results or -1 for random generation.
  6. Submit — Generate and retrieve the finished image.

Pricing

ResolutionPrice per Image
1K$0.020
2K$0.080

Aspect ratio, output format, and seed do not add separate charges.


Best Use Cases

  • Posters and promotional graphics — Generate visuals with Chinese or English text.
  • Packaging concepts — Create product packaging and label designs.
  • Infographics — Combine visual elements with readable text.
  • Advertising creatives — Produce campaign and marketing concepts.
  • Editorial imagery — Generate detailed compositions for publishing and social content.
  • Creative image generation — Explore illustrations, photography, and stylized concepts from long-form prompts.

Pro Tips

  • Describe the subject, composition, environment, lighting, and style clearly.
  • Put text that should appear in the image inside quotation marks.
  • Use detailed prompts when precise scene structure matters.
  • Choose 2k when higher output detail is needed.
  • Use a fixed seed when comparing prompt or parameter changes.

Notes

  • prompt is required.
  • resolution defaults to 1k.
  • aspect_ratio defaults to 1:1.
  • output_format defaults to jpeg.
  • Use seed=-1 for random seed selection.
  • Both Chinese and English text can be included in prompts and rendered in generated images.

Authentication

For authentication details, please refer to the Authentication Guide.

API Endpoints

Submit Task & Query Result

set -euo pipefail

export WAVESPEED_API_KEY="your-api-key"

REQUEST_BODY=$(cat <<'JSON'
{
  "prompt": "A cinematic ocean wave at sunrise, highly detailed",
  "aspect_ratio": "1:1",
  "resolution": "1k",
  "output_format": "jpeg"
}
JSON
)

# 1. Submit the prediction once. Never retry this request automatically:
# a retry after an unclear failure can create a second, billed task.
CHECK='The task may already exist. Check History or the predictions list before submitting again.'
if ! SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  --connect-timeout 10 --max-time 60 \
  -X POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/moss-image/text-to-image" \
  -H "Authorization: Bearer ${WAVESPEED_API_KEY}" \
  -H "Content-Type: application/json" \
  -d "${REQUEST_BODY}"); then
  printf 'Submit failed. %s\n' "${CHECK}" >&2
  exit 1
fi

TASK=$(printf '%s' "${SUBMIT_RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
PREDICTION_ID=$(printf '%s' "${TASK}" | jq -r '.id // empty')
if [ -z "${PREDICTION_ID}" ]; then
  printf 'Submission response did not contain a prediction id. %s\n' "${CHECK}" >&2
  exit 1
fi
RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result"

# 2. Poll until the prediction reaches a final status.
BODY_FILE=$(mktemp)
trap 'rm -f "${BODY_FILE}"' EXIT
while true; do
  # Transient errors (429, 5xx) are retried, honoring Retry-After.
  HTTP_CODE=$(curl --silent --show-error --fail-with-body \
    --connect-timeout 10 --max-time 60 --retry 5 --retry-delay 2 \
    --output "${BODY_FILE}" --write-out '%{http_code}' \
    "${RESULT_URL}" \
    -H "Authorization: Bearer ${WAVESPEED_API_KEY}" || true)
  case "${HTTP_CODE}" in
    2??) ;;
    000|429|5??)  # dropped connection or temporary error: keep polling
      printf 'Task %s: HTTP %s, polling again in 10s\n' "${PREDICTION_ID}" "${HTTP_CODE}" >&2
      sleep 10; continue ;;
    *) printf 'Task %s: HTTP %s\n' "${PREDICTION_ID}" "${HTTP_CODE}" >&2
      cat "${BODY_FILE}" >&2; exit 1 ;;
  esac
  RESULT=$(jq 'if type == "object" and has("data") then .data else . end' "${BODY_FILE}")
  STATUS=$(printf '%s' "${RESULT}" | jq -r '.status // empty')

  case "${STATUS}" in
    completed) printf '%s\n' "${RESULT}" | jq '.outputs'; break ;;
    failed|cancelled|timeout|deleted)
      printf 'Task %s ended with status %s\n' "${PREDICTION_ID}" "${STATUS}" >&2
      printf '%s\n' "${RESULT}" | jq . >&2; exit 1 ;;
    *) sleep 2 ;;
  esac
done

Retry temporary errors only while polling, never the submit request. Errors, retries and timeouts

Parameters

Task Submission Parameters

Request Parameters

ParameterTypeRequiredDefaultRangeDescription
promptstringYes-The positive prompt for the generation. Supports long, detailed prompts and Chinese and English text rendering inside the image.
aspect_ratiostringNo1:11:1, 1:2, 2:1, 1:3, 3:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 9:21, 21:9The aspect ratio of the generated image.
resolutionstringNo1k1k, 2kTotal output resolution tier: 1k (~1 megapixel) or 2k (~4 megapixels).
output_formatstringNojpegjpeg, png, webpThe format of the output image.
seedintegerNo--The random seed to use for the generation. -1 means a random seed will be used.
enable_sync_modebooleanNofalse-If set to `true`, the request attempts to wait for the generated result and return outputs in the same response. If the result is not ready within the sync wait window, the API can return a timeout body while the task continues processing. This option is only available via the API and is supported only by some models.
enable_base64_outputbooleanNofalse-If set to `true`, the prediction's `output` strings are returned as **naked base64** (no `data:<mime>;base64,` prefix). When `false` (default), outputs are returned as URLs pointing to our CDN.

Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
data.idstringUnique identifier for the prediction, Task Id
data.modelstringModel ID used for the prediction
data.outputsarrayOutput values, usually URL strings; some models return text strings or structured result objects (empty when status is not completed)
data.urlsobjectObject containing related API endpoints
data.statusstringTask status. completed is successful; failed, cancelled, timeout, and deleted are failure terminal statuses.
data.created_atstringISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”)
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds

Result Request Parameters

ParameterTypeRequiredDefaultDescription
idstringYes-Task ID

Result Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
dataobjectThe prediction data object containing all details
data.idstringUnique identifier for the prediction
data.modelstringModel ID used for the prediction
data.outputsarray<string | object>Array of generated outputs (empty when status is not completed). Items are usually URL strings, but may be text strings or structured result objects, depending on the model.
data.urlsobjectObject containing related API endpoints
data.statusstringStatus: completed is successful; failed, cancelled, timeout, and deleted are failure terminal statuses
data.created_atstringISO timestamp of when the request was created
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds
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