Eversince — Creative Agent API

You are briefing a creative agent. It reasons through your brief, makes creative decisions, selects AI models, generates images, videos, voiceovers, music, sound effects, motion graphics, and delivers either rendered assembled video or standalone assets as requested. Generate from scratch or hand off your own assets — images, video, audio, URLs — and the agent builds around them.

Full documentation: https://docs.eversince.ai

Requirements

• API key required. This skill authenticates with an Eversince account via EVERSINCE_API_KEY. Get one at https://eversince.ai/app/settings.
• Paid usage. Generations consume credits from the user's Eversince account. Use POST /estimate-cost to preview costs and GET /account/credits to check balance before running.
• External calls. All requests go to https://eversince.ai/api/v1. Optional webhook_url sends status updates to a user-specified URL.

Setup

Base URL: https://eversince.ai/api/v1

Authentication: API key in the Authorization header.

Authorization: Bearer YOUR_API_KEY

Get your API key at https://eversince.ai/app/settings. Once you have a key, you can create additional keys via POST /keys, list them via GET /keys, and revoke via DELETE /keys/:id.

Quick Start

1. Create a project

curl -X POST https://eversince.ai/api/v1/projects \
  -H "Authorization: Bearer $EVERSINCE_API_KEY" \
  -H "X-Eversince-Source: plugin" \
  -H "Content-Type: application/json" \
  -d '{
    "brief": "Your creative brief here",
    "mode": "autonomous"
  }'

Response (202):

{
  "id": "abc12345-def6-7890-abcd-ef1234567890",
  "status": "queued",
  "mode": "autonomous",
  "project_url": null,
  "credits_balance": 4200,
  "created_at": "2026-03-30T12:00:00Z"
}

2. Poll for status

curl https://eversince.ai/api/v1/projects/PROJECT_ID \
  -H "Authorization: Bearer $EVERSINCE_API_KEY" \
  -H "X-Eversince-Source: plugin"

Poll until the status reaches idle, failed, or cancelled. The status can be one of:

3. Get the result

When status is idle, the response includes:

• output_type — assembled (rendered video available), assets (individual files, no render), or pending (still processing)
• assembled_url — the rendered video from the active state of the timeline, if the project produced one (expires after 24 hours, re-render to refresh)
• agent_message — the agent's latest message
• project_url — link to the project in the Eversince studio
• variation_id — the active variation ID

To get all generated assets (images, videos, audio): GET /projects/:id/assets To get the full timeline structure of the active variation: GET /projects/:id/timeline To get the conversation history: GET /projects/:id/messages To get all variations: GET /projects/:id/variations To read the agent's working memory: GET /projects/:id/memory If the project has an assembled_url, a permanent shareable link can be created via POST /projects/:id/share

What the Agent Can Do

Production

• Image generation — text-to-image, image-to-image, reference-based (multiple references for character consistency, style matching), multiple variants per call
• Video generation — text-to-video, image-to-video, video-to-video, multi-shot direction (up to 6 segments), audio-synced generation (lip-sync, rhythm), camera motion presets
• Video production — multi-scene timelines, storytelling structure, pacing, scene management, generation selection, fade control
• Voiceover — script writing and speech generation in 60+ languages, voice selection, speed control, voice transformation
• Music — instrumental or with lyrics across three models (ElevenLabs, MiniMax, Google Lyria), each with different strengths
• Sound effects — ambient audio, impacts, transitions, duration and loop control
• Captions — three presets (impact, clean, kinetic), word-level sync
• Text and logo overlays — titles, taglines, CTAs, brand elements, positioned and timed on the timeline
• Motion overlays — animated graphics, kinetic text, data visualizations via Remotion

Post-production

• Variations — parallel creative directions, A/B testing, multi-format delivery from the same project
• Aspect ratio — 16:9, 9:16, 1:1, 21:9 with timeline reframing (creates a new variation)
• Language change — translate voiceover + text overlays to 60+ languages (creates a new variation)
• Upscaling — 4x image upscale, video upscale to 4K
• Background removal — transparent PNGs from any generated or uploaded image
• Image cropping — extract panels from grid images or crop custom regions

Intelligence

• Media analysis — multimodal analysis of generated images, videos, and audio to evaluate results
• Audio transcription — word-level timestamps for caption alignment and lyric sync
• Web research — search the web for trends, competitors, and cultural context
• X/Twitter search — trending topics, cultural moments, brand sentiment, competitor activity
• URL extraction — drop a URL as a reference, the agent extracts content and media
• Cost estimation — estimate credit costs for planned operations before executing

For long-term projects (campaigns, series, catalogs), see references/advanced-patterns.md.

Project Options

The brief is your primary input. The agent makes all creative decisions from it — concept, visuals, models, pacing, audio, everything. Include production preferences (voiceover, music, captions, duration, style) in the brief text — there are no separate fields for these. You can also attach reference files and URLs.

brief is the only required field. Everything else is optional:

File uploads: To attach files as references, use the three-step presigned upload flow: POST /uploads → PUT the file to the returned upload_url (no auth header, Content-Type must match what you specified) → POST /uploads/confirm → use the returned upload_id in references. URLs can also be passed directly as references without uploading: {"url": "https://...", "type": "url"} (max 3 per request). See references/api-reference.md for accepted file types, size limits, and full request/response shapes.

Voices: GET /voices lists available voiceover voices with name, gender, age, accent, style, and description. Filter by gender with ?gender=male|female|neutral. Include the voice name in your brief to request a specific voice.

Craft values:

• auto — agent selects the best craft for the brief (default)
• general — flexible creative output across any format, style, or use case
• cinema — shot design, camera movement, emotional pacing
• ugc — platform-native for TikTok, Reels, Shorts
• photography — hero shots, detail work, lifestyle compositions
• animation — character-driven storytelling, expressive motion
• music — song generation, music videos, beat-synced visuals
• motion-graphics — animated text, data visualization, graphic storytelling

Two Modes

Autonomous (default)

The agent handles everything from start to finish. For video projects: plans → generates → verifies → renders → done. For asset projects: plans → generates → done.

Collaborative

The agent stops at key decision points, returning idle status with its response in agent_message. Send feedback via POST /projects/:id/messages, and the agent continues.

Switch modes mid-project: PATCH /projects/:id/settings with {"mode": "collaborative"} or {"mode": "autonomous"}.

Working with the Agent Over Time

Supports ongoing collaboration as well as one-off creative work.

• Skills — teach the agent persistent knowledge (brand guidelines, style rules, workflow preferences, etc.) via POST /account/skills. List via GET /account/skills, read via GET /account/skills/:id, toggle on/off via PATCH /account/skills/:id, delete via DELETE /account/skills/:id. Apply across all projects.
• Learned preferences — the agent learns preferences, brand voice, and creative patterns across projects. Read via GET /account/learned-preferences, update via PUT /account/learned-preferences.
• Project history — list all projects via GET /projects with ?status=, ?title=, ?limit=, ?offset= filters.
• Shared content — list all public share links and view counts via GET /account/shares.
• Long-term projects — for campaigns, series, or ongoing creative work, manage the long-term plan externally and hand the agent focused tasks. See references/advanced-patterns.md.
• Project discovery — adopt projects created in the studio for API management via GET /projects/discover and POST /projects/adopt. See references/advanced-patterns.md.

Polling Strategy

Use status-aware intervals:

Webhooks are available as an alternative to polling. Set webhook_url at project creation. Webhooks fire on status transitions (running, generating, idle, failed, rendering) with the full project state including agent_message, timeline, and assets. Note: cancelled does not fire a webhook.

Webhooks include X-Eversince-Signature (HMAC-SHA256) and X-Eversince-Timestamp headers for verification. Contact support@eversince.ai to set up a signing secret. 10-second timeout, no retries — if your endpoint is unavailable, the event is lost.

See references/api-reference.md for webhook event details.

Credits and Costs

• Check balance: GET /account/credits — returns credits_balance. Check before starting work.
• Estimate costs before executing:

curl -X POST https://eversince.ai/api/v1/estimate-cost \
  -H "Authorization: Bearer $EVERSINCE_API_KEY" \
  -H "X-Eversince-Source: plugin" \
  -H "Content-Type: application/json" \
  -d '{"operations": [
    {"tool": "generate_image", "model": "nano-banana-pro", "count": 2},
    {"tool": "generate_video", "model": "seedance-2.0", "duration": 5, "count": 1}
  ]}'

Returns total_credits and per-item breakdown. Tools: generate_image, generate_video, generate_audio, upscale_media, analyze_media, remove_background, motion_overlay. See references/api-reference.md for the full operation schema.

• Low balance warning: when balance drops to 100 or below, GET /projects/:id responses include a credits_warning field. When you see it, proactively fetch purchase options and present a link to the user before the balance hits zero.
• When credits run out: on insufficient_credits (402), fetch purchase options and present the link to the user:

curl https://eversince.ai/api/v1/account/credit-packages \
  -H "Authorization: Bearer $EVERSINCE_API_KEY" \
  -H "X-Eversince-Source: plugin"

Returns packages[] with credits, price, and purchase_url for each option.

Error Handling

Errors return {"error": {"code": "string", "message": "string", "status": 400}}. Key codes: validation_error (400), insufficient_credits (402), project_limit (429), rate_limited (429/503). When status is failed, the response includes error_message.

When a project fails: Create a new project. Failed projects cannot be resumed or retried — start fresh with the same or adjusted brief. Check error_message for what went wrong.

When POST /messages returns 400: The agent isn't idle yet. Poll GET /projects/:id until status reaches idle, failed, or cancelled before sending another message.

See references/api-reference.md for the full error format, response headers, and rate limits.

Feedback

Report bugs, suggestions, or questions directly via POST /feedback with {"type": "bug | suggestion | question", "message": "string"}.

Settings: API vs Agent Messages

Some settings are changed via the API, others must go through the agent because they affect the timeline:

Via PATCH /projects/:id/settings (project-level config):

• mode, video_model, image_model, agent_model, craft, craft_auto, webhook_url, title, expected_output

Via POST /projects/:id/messages (timeline operations the agent performs — PATCH /settings will reject these with a validation error):

• Aspect ratio — "Change aspect ratio to 9:16"
• Language — "Change language to Spanish"
• Captions — "Enable kinetic captions" / "Turn off captions"
• Variations — "Duplicate the current variation" / "Switch to variation [id]"

Limits

• Minimum credits: 50 to create a project, 10 to send a message, 10 to render.
• Concurrent projects: up to 5 projects in queued, running, generating, or rendering at the same time. Daily limit: 500 projects.
• Agent runs in cycles — the agent works, dispatches generations, waits for results, then continues automatically (up to 25 cycles per run). Monitor progress via status polling or webhooks. Cancel at any time via POST /projects/:id/cancel.
• assembled_url expires after 24 hours. Re-render via POST /projects/:id/render (50 renders/day). Create a permanent link via POST /projects/:id/share.
• 4K rendering requires a Pro subscription. 1080p is the default.
• Cancel stops the agent, not in-progress generations. Already-dispatched generations will complete, but the agent won't continue after them.
• No project deletion. Projects cannot be deleted via the API. Cancel active ones with POST /projects/:id/cancel.
• Idempotency: if you send an idempotency_key and a non-failed project exists for that key, the API returns 200 with the existing project instead of creating a new one.
• JSON payload limit: 1 MB max per request. File uploads have separate limits (see POST /uploads).

Studio Handoff

When iteration is complete and the user wants to continue working in the Eversince studio, clear the API context:

curl -X PATCH https://eversince.ai/api/v1/projects/PROJECT_ID/settings \
  -H "Authorization: Bearer $EVERSINCE_API_KEY" \
  -H "X-Eversince-Source: plugin" \
  -H "Content-Type: application/json" \
  -d '{"mode": "none"}'

Reference Files

For the full endpoint catalog and request/response shapes: references/api-reference.md.

For long-term projects, parallel projects, variation workflows, and teaching the agent: references/advanced-patterns.md.