Scenario
Overview
Scenario (scenario.com) generates AI images, video, 3D, and audio across 500+ models plus custom training, all through the core loop below.
Setup
Endpoint:
https://mcp.scenario.com/mcp
(Streamable HTTP). Prefer OAuth: no credentials pass through the conversation. Client config, API-key setup for headless use, and per-client re-authentication:
references/setup.md. Never ask an agent to collect, encode, or echo a secret. A connection that authenticated once and fails later is re-authenticated per client before anything else is debugged: a server-side authentication fix lands only through a fresh handshake, and
names the failing layer (
,
,
, or
) with trace ids for support.
The default toolset is wider than the core loop below:
,
,
and
are in it too and are called directly, so treat the table as the loop rather than the whole list.
exposes everything. The catalog tools are the ones outside it (collections, tagging, analysis, training, members, keys):
with the tool name or plain keywords as
(it takes only
and
) returns the schema and lane, and the matching
scenario_tool_execute_read
/
/
runs it with
, scope ids inside
when the target's
declares them, which nearly every catalog tool does (
, which takes only
, is the exception), unlike a direct tool's top-level
/
. The lane is the result's own
, not what the verb sounds like:
and
are both write-class.
Scope first
Resolve scope first, then pass
and
on every later call.
returns the teams with their projects;
requires a
, so it cannot come first. Confirm the pair with the user: a guess writes into someone else's project. A non-interactive run takes the pair from its task instructions; when they name none, stop and list the choices.
The server fills scope in only for read-only tools with one candidate remaining; anything else fails rather than guesses, and the error names which half is wrong (see Errors and recovery). Scope errors are the most common failure here, surfacing mid-session on the first call that drops the pair once a second team or project is in play.
Quick reference
| Step | Tool | Notes |
|---|
| Resolve scope | , then | Once per session; pass the ids on every call |
| Find a model | or | Free; for a capability, for a name |
| Get the schema | | Always before ; check and caps |
| Generate | | Schema-conformant ; for cost |
| Wait | | Whenever returns a without assets; never loop |
| View / save | / | Never paste raw asset URLs; converts images only |
| Inspect an asset | | Free; dimensions, duration, / ids |
| Upload inputs | + | Local files become asset_ids |
| Refine a prompt | | Advisory rewrite; needs |
| Quota / debugging | , | CU consumption; MCP prompt |
A multi-step request ("product video with voiceover", "concept to 3D") goes to
(catalog-only, read lane): plain words in
, ordered steps out, each naming a tool and optional model hint; it runs nothing. Single-step:
.
Worked example
Generating a stylized game prop image:
- with the user's own words as when the need is a capability; with , , when you have a name. ranks by keyword and its hold no capability key, so a capability-worded query can rank the wrong output type first. For the user's own trained models, omit on ( has no private flag); on the flag is
include_private_models: true
. Re-discover ids each time: availability differs per team.
- on the pick: exact field names, types, required flags, defaults, and caps such as the prompt's (an overrun is a 400, never a trim). File fields take asset ids even when named , and flags what moves the price.
- If the schema carries ( or ), never send that model's own id to . Its
run_with.required_arguments
holds the real call: there is the base model, and its (the or wiring) merge into inputs from the same schema. Sending alone discards your prompt.
- Optional: rewrites a thin prompt into an on-model one; pass the discovered id (a LoRA's own, not its base) and the draft . Skip deliberate prompts.
- with and schema-conformant . If cost matters (the default assumption unless the user says otherwise), price first with , a top-level argument beside : no job is created and the response's is the exact payload's price; a cost quote assumes defaults, and the schema's fields move the real number. Then run: asset_ids come back, or a for . The beside it is when the server's wait budget ran out; with it is the backend's live word at creation (, , ), a spelling that is not a different state.
- with (up to 32); each completed row carries and , so no follow-up; on timeout re-call with the returned as . Failed jobs are reimbursed, except xAI generations stopped by moderation.
- shows the asset inline; its picks the rendering: (the default) returns an inline image plus links and viewer data; returns a lighter payload for a host that renders the interactive widget; and return metadata and links. does not disable a host's widget. For PNG files, use with , one call per asset. returns a file URL (save with , it may redirect). is an image conversion (, , , and to keep an animated GIF animated: the default flattens it to one frame) and nothing else; omit it for video, 3D, and audio. When reports or
CONNECT tunnel failed, response 403
while MCP calls work, check the host's proxy or sandbox egress policy. A CDN 403 alone does not establish the cause; request a fresh download URL before diagnosing it: Sandbox network access names the setting that lifts it, an organization-level allowlist on some hosts that the user may not be able to change. Meanwhile hand over the that returns, where the user downloads directly and, for a mesh, picks the 3D export format the app offers, none of which converts to. The signed URL also opens in a browser but expires, so it is a last resort, never the deliverable.
Local inputs go up with
: always
,
, and
(
,
,
,
), plus exactly one of
or
, since the call fails without either. Prefer
, the file's exact byte count read from disk, and omit
: the reply carries presigned part URLs and
; PUT each part's raw bytes to its URL with no added headers (a checksum header makes the store answer 403), check every PUT returned 200, then
with the
. Inline base64
only under 100KB (that path returns the asset directly, with no complete step); a larger file is rejected naming the cap. Scope rides on both; they take no other fields: no parts list, no etags. The server decodes the file at completion, so
Upload upl_… failed: Corrupt JPEG data
,
premature end of data segment
,
or
means the uploaded image could not be decoded: check for a corrupt source, a truncated or re-encoded body, a missing part, or a mismatched
. Confirm the local file opens, its content type matches, and its byte count is correct, then start over with a fresh
and raw PUTs; never re-complete the same
.
at upload lists what
accepts: convert locally first. A host with no shell cannot PUT parts at all; the user uploads in the web app at app.scenario.com and the agent continues from the asset id.
Filing is part of delivering, not a tidy-up: run the catalog tools above with arguments under
(never
, which the executor drops silently, surfacing as a scope error that is not one).
takes a name and the scope pair only;
sent there is ignored without an error, so adding is always a second call,
with
and
, and re-adding a filed asset is a hard 400 naming the duplicate: drop it and continue. Confirm membership with
and read each record's
;
filters={"collection_ids": [...]}
lags on a fresh write.
takes at most 49 ids per call (past it, 400
You can not add more than 49 assets at once
), so chunk a larger set.
is additive, one
per call, so a set is one call per asset, and a tag the asset already carries returns 400
: read
off
first and send only the missing ones; skip the write when none are missing.
For reusable templates or reference content, follow the shared asset lifecycle: resolve existing assets, stage new versions, publish only through a supported operation, and verify public access before recording public IDs. Uploading and filing alone are not publication.
Errors and recovery
| Error | Recovery |
|---|
| Nothing resolved: , then |
| Several fit: present the options; the user picks (non-interactive: task instructions name the pair, else stop and list) |
| 403 Forbidden | Usually wrong scope, not missing: re-check the id pair |
| 403 naming a plan | Surface the upgrade or switch models; retrying never clears it. pre-flags these as (never run one) unless its response says plan gating is ; then this row is the backstop |
| 429 with = | Per-team generation concurrency ceiling: keep at most jobs in flight, use for launches and to retire existing jobs before launching more. An immediate retry repeats the error |
| 429 naming a quota, balance, or seat limit | Read the reason and together, including and when present. Generic plan-limit wording alone does not distinguish concurrency from consumption or feature access. A CU limit does not prove the balance is zero; the requested run may exceed what remains. Stop the affected batch, use for consumption, and report the stated remedy. A per-user cap goes to the team admin; a seat-cap error can also block uploads. Do not change billing or membership automatically |
| 429 with an explicit retry delay | Respect the returned delay before retrying; this is not evidence that the user needs an upgrade |
| Other 429, including an unfamiliar | Do not classify every other action as a count quota, or infer a training quota's behavior from its name. Report the error and run in the same scope before choosing recovery |
| timeout () | Not an error: re-call with the returned , never a second or a cancel; it takes no timeout argument |
| Transport error on (no HTTP status) | The request may still have landed: before any re-run, or a lost response becomes a double charge; a call creates no job and always retries safely |
400 Cannot cancel this type of job
| A launched job is committed spend: rejects most generation jobs, so plan batches with no abort path |
| 400 | converts images only: omit it for video, 3D, audio |
Either 'file_size' … or 'data' is required
on | Read the byte count from disk and send it as (omit ); inline is for files under 100KB only |
Upload upl_… failed: Corrupt JPEG data
(or ) | The uploaded image could not be decoded: check the source file, content type, byte count, and part transfers before a fresh upload; re-completing does not repair corrupt bytes |
| 404 on | The id does not exist and no retry makes it appear: re-read off the or row, since a guessed or mistyped id is the usual cause |
400 At least one of query, filter, image, or images must be provided
| never lists bare: a "newest first" asset listing is , filter="createdAt EXISTS"
with sort_by=["createdAt:desc"]
|
| client-side timeout | It ranks on live data and commonly runs 30 seconds, sometimes over a minute: wait or re-call it; do not fall back to for a capability |
Common mistakes
- A bare value where the schema says : silently dropped, the run ignoring your reference or LoRA. on the output echoes what the run consumed (, ), the cheapest proof it was not.
- Taking 's blindly: read first. On , present the options; the user's pick wins (non-interactive: task instructions, else ). On , prefer , else the first entry its own text does not mark deprecated, reading and as well as , since the flag lands in any of them: the ranking is by measured performance, not by lifecycle, so a deprecated member can top it.
- Debugging blind: the MCP prompt (or with the scope pair the failure happened under and any ids seen as ) returns trace ids; answers credit questions.
- Guessing a file field's name: 400 (or , , , , , , each a different model's name for the same idea) means the payload never carried the field the schema's list names, so copy that name verbatim; a URL in a file field reads as missing too, since file fields take asset ids only.
- Feeding an image field a video, audio, or 3D asset: 400 lists the image types it accepts. reports the asset's ; pull a still with the clip's when the model wants an image.
- on with : a 400
"kind" is not a filterable field
, since describes assets. Narrow models with (the architecture) or , or go through for a capability.
- Filtering by without : a 400 says so. A private listing narrows by or , or goes through (private by default).