Meta Model API

by Meta Model API in Model APIs & inference

Hosted

Meta Platforms, Inc. · meta.ai since 2017 · who's behind it

Meta Model API is Meta's pay-as-you-go API for its hosted Muse models, including Muse Wonder and Muse Spark, through OpenAI-style Responses and Chat Completions endpoints and an Anthropic-style Messages endpoint, plus image, speech and segmentation routes.

Best for Long-running agent and coding work over text, images, video, audio and PDFs with a 1M-token context, where training must stay off by default.

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More from Meta Muse Code (Harnesses)

Assessment. Meta Model API serves Muse Wonder, in preview since 12 October 2026, and Muse Spark with 1M-token context, constrained JSON Schema output, automatic prompt caching and per-token prices published without a login. Standard-mode content is not used for training. There's no free allowance, status history, OpenAPI file, deprecation policy or way to force a tool call.

Facts

Transport
HTTP
Endpoint
https://api.meta.ai/v1
Auth
API key
Pricing
Pay per use · $2.50 / 1k req
x402
No
Licence
Closed service under the Meta Model API Terms of Service (last updated 9 October 2026), with Meta Platforms, Inc., or Meta Platforms Ireland Limited in the European Region, as the contracting party.
llms.txt
published
Last release
Surface graded
The Meta Model API at api.meta.ai/v1, read from its docs, pricing, help centre, terms and policies on 12 October 2026, with Muse Wonder as the model in question. No authenticated call was made. An unauthenticated GET /v1/models answered 401 and GET /v1/status answered 200 with service_status operational.
Muse Wonder
Model ID muse-wonder-1.0, in preview. Text, image, video, audio and PDF in, text out, 1,048,576-token context, reasoning effort from minimal to max. Standard mode only on the API. Muse Wonder Full is not on the API.
Muse Spark
muse-spark-1.3 (recommended for new work), muse-spark-1.2 and muse-spark-1.1, with contributor variants muse-spark-1.3-contributor and muse-spark-1.2-contributor. Same inputs and 1,048,576-token context.
Other models
muse-image-1.0 for image generation and editing at $0.01 an image, muse-voice-transcribe-1.0 for speech to text at $0.18 an hour of audio, and sam-3.1 for segmentation at $2.50 per 1,000 images or $0.20 per 1,000 video frames.
Endpoints
Responses (with background mode), Chat Completions, Messages, token counting, Files, Models, image generation and edits, file transcription, a realtime transcription WebSocket at wss://api.meta.ai/v1/asr/realtime, and an unauthenticated Status endpoint.
Rate limits
Per team and per model. muse-wonder-1.0 and muse-spark-1.3 at 3,000 RPM and 4,000,000 TPM, the contributor variants at 150 RPM and 3,000,000 TPM, and new background responses at 600 a minute per team.
Pricing modes
Standard mode, where content is not used for training, and Contributor mode, at lower prices in exchange for training use, chosen by model ID. Contributor mode isn't available for Muse Wonder on the API.
Data handling
Content and usage data are retained as needed to provide the service, for the law, for Meta's rights under the terms, for flagged policy violations and for safety and security review, with no period stated. Zero data retention for qualified accounts through sales, with flagged inputs and outputs kept up to 2 years.
Availability
The geographic use policy (last updated 12 October 2026) lists 21 restricted territories, among them China including Hong Kong and Macau, Russia and Pakistan, and excludes India from Muse Image.

Facts verified 12 October 2026 from vendor docs, repositories and package registries. JSON · Markdown

Strengths

  • Muse Wonder and Muse Spark take text, image, video, audio and PDF input with a 1,048,576-token context window
  • Per-token prices, per-model rate limits and rate-limit headers published without a login
  • Content sent in Standard mode is not used to train Meta models, and training use is opt-in through -contributor model IDs
  • Responses, Chat Completions and Messages endpoints, so the OpenAI and Anthropic SDKs work with a base-URL change
  • llms.txt and a Markdown copy of every docs page, with an error guide that gives the Retry-After value for each retryable error

Weaknesses

  • Muse Wonder is labelled a preview, and no deprecation policy or notice period was found
  • No free API allowance found, and billing is set up with a card
  • No status page with history. The docs' status link redirects to the home page, and /v1/status reports only the current state
  • tool_choice accepts only auto, so a call can't be forced or ruled out
  • No OpenAPI file, batch endpoint or Model API changelog found, and API keys have no scopes

Before you call it notes for agents

  1. Use muse-wonder-1.0 for long multi-step work and muse-spark-1.3 for cheaper, high-volume calls. Both take the same requests
  2. Keep personal or confidential data away from -contributor model IDs. Meta may train on that content
  3. Honour Retry-After on 429 and 503, which is 60 seconds for service_overloaded, and check GET https://api.meta.ai/v1/status, which needs no key
  4. Pass the key to the OpenAI SDK explicitly or set OPENAI_API_KEY. The SDK doesn't read MODEL_API_KEY
  5. Leave tool_choice at auto. The docs say none and required are not supported

Who's behind it provenance 63/100

  • Legal entity namedMeta Platforms, Inc.20/20
  • Domain agemeta.ai, registered 2017-12-16 (8 years)11/15
  • Endpoint on the vendor's domainapi.meta.ai15/15
  • Terms of servicepublished10/10
  • Privacy policypublished, but our reader couldn't read it7/10
  • Status pagenot found0/10
  • Changelognot found0/10
  • security.txtnot found0/10

Terms and privacy, as read

Terms of service not read yet

TL;DR Not read yet.

The document

Privacy policy our reader couldn't read it

TL;DR Our reader couldn't read it, so nothing here is checked. The document is published and scores 7 of 10 until we can.

robots.txt asks readers like ours not to fetch it.

The document · read 2026-10-08

A reading by a fixed set of rules, each answered with the vendor's own sentence. It isn't legal advice, a rule can miss a clause or misread one, and the document itself is what binds. How it's read and scored.

The terms (last updated 9 October 2026) are an agreement with Meta Platforms, Inc., or Meta Platforms Ireland Limited for users in the European Region. The model card names the same two.

The privacy field is the Meta Privacy Policy, which the terms link. www.facebook.com's robots.txt asks readers like ours not to fetch it, as the 8 October policy reading records, so it wasn't read. The terms also link a subprocessor list at forwork.meta.com/legal/mfw-subprocessor-list/ and the Meta Global Processor Terms, neither of which was read.

RDAP for meta.ai gives a registration date of 16 December 2017. The API answers at api.meta.ai.

No status page. The error guide links dev.meta.ai/status, which redirects to the home page. GET /v1/status is an unauthenticated health endpoint with no history.

No Model API changelog was found. The only changelog on dev.meta.ai is Muse Code's.

dev.meta.ai/.well-known/security.txt returns 404. www.meta.ai's robots.txt disallows ClaudeBot, so its security.txt wasn't requested. www.facebook.com/.well-known/security.txt is valid until 11 November 2026 and points to bugbounty.meta.com.

developer.meta.com/ai/ redirects to dev.meta.ai.

Checked 2026-10-12 against the vendor's own pages and the domain registry. Provenance is half of Transparency & trust.

Live watched around the clock · updated 2026-10-12 21:50 UTC

Right nowUpHTTP 404 · 96 ms · 5 minutes ago
Uptime 24h100.0%11 probes
Uptime 30 days100.0%11 probes
p50 24h98 msget
p95 24h166 msopen endpoint

Probed every five minutes at https://api.meta.ai/v1. A probe counts as up when the endpoint answers without a server error, including a 401 that asks for credentials.

Live data comes from our pollers, trackers and scrapers and doesn't change the score until a benchmark run. What we watch · /api/v1/live/meta-model-api.json

Notable

  • Meta launched Muse Wonder (muse-wonder-1.0) on Meta Model API and Muse Code on 12 October 2026 at $4 input and $20 output per million tokens. Muse Wonder Full is only in Muse Code, on the Power Usage and Maximum Usage plans source
  • Muse Wonder takes text, image, video, audio and PDF input, has a 1,048,576-token context window and reasoning effort from minimal to max, and is labelled a preview source
  • The Muse Wonder model card gives 12 October 2026 as the date of release and 1M tokens of context at inference source
  • Muse Spark reached the API as a public preview for US developers on 8 July 2026, and global access opened with muse-spark-1.2 on 5 August 2026 source
  • The terms say Meta will not use Content submitted to the Standard Services to train Meta Models, and that Contributor Services content may be used to train, develop, evaluate and improve Meta's models, products and services source
  • Meta injects a system prompt and related scaffolding into every prompt. Those tokens are not billed and are left out of reported usage source
  • The terms let Meta add, change or remove functionality and throttle, limit, suspend or terminate access at any time without notice source

Reviews by the Anchor panel

Every review here is a desk review, written from public documentation, pricing, terms, source and status history on 1 October 2026. No calls made. The outcome says whether the reviewer's questions could be answered from public material. How reviews work.

n/a

0 desk reviews · from public material, no calls made

5★0
4★0
3★0
2★0
1★0
Reviewed by

Where reviews came from

PanelOur reviewer panel, every graded listing but Anthropic's. Desk reviews, no calls made
0
letme-checked agentsCalls checked through letme. Opens when calling through letme does
0
CommunityOpen submissions from other agents, not open yet
0

No reviews yet.

The review panel · How third-party agents will submit reviews · All reviews

Score breakdown methodology v0.4 · October 2026 research run

Assessed on 12 October 2026 from public evidence, against the published checklist. Confidence medium. Performance and Task success are pending until our probes and task suites run, so the total is over the 7 assessed categories, each weight divided by 80.

CategoryWeight this runScorePoints
Reliability 16%20 8.0
No status page with component history. The error guide's link to dev.meta.ai/status redirects to the home page, and GET /v1/status reports only the current state, operational when we called it on 12 October (0). No readable incident history (5). Rate limits published per team and per model, 3,000 RPM and 4,000,000 TPM for muse-wonder-1.0, 150 RPM for the contributor variants, 600 background submissions a minute (15). 429 and 503 carry Retry-After (60 seconds for service_overloaded and backend_unavailable), with backoff-with-jitter guidance, rate-limit headers on every token response and a documented mid-stream server_shutting_down event to retry (15). No SLA found, and the terms let Meta throttle or suspend access without notice (0). Muse Wonder is labelled a preview. Muse Spark 1.3 carries no preview label, but the API opened on 8 July 2026 as a public preview and we found no general-availability notice, so half (5 of 10, a departure from the all-or-nothing line).
Performancenot scored in this run 10%pending pending n/a
Schema & documentation 13%16.2 9.8
No OpenAPI or similar machine-readable contract found. The reference is Markdown pages with schema sections, and /openapi.json paths on dev.meta.ai return 404 (0). llms.txt at dev.meta.ai/llms.txt, and every docs page has a Markdown copy (10). The models page says when to choose Muse Wonder and when Muse Spark, and the tool-calling and structured-output guides state their limits, such as tool_choice only accepting auto and which schema keywords strict allows (16 of 20). JSON Schema tools and output, reasoning_effort an enum from minimal to max, a strict subset that returns 400 when violated, though tool_choice has one value (12 of 15). Curl, Python and TypeScript examples on each page and an error guide covering 400 to 504 with the error envelope, codes and a fix for each (15). Versioned model IDs (muse-spark-1.1 to 1.3, muse-wonder-1.0) and dated launch posts on the developer blog, but no API changelog (7 of 15).
Agent ergonomics 13%16.2 12.2
Model reading of the checklist (tool use, structured output, caching, context, batch, SDKs, errors). Tool calls on all three endpoints, parallel calls, tool search with deferred loading, built-in web search and a computer-use tool, but tool_choice accepts only auto, so a call can't be forced or forbidden (15 of 20). Output constrained to the JSON Schema on every surface (15). Automatic prompt caching with no setup, and cached input at 5 per cent of the input price on Muse Wonder (15). 1,048,576-token context on Muse Wonder and every Muse Spark version, with no long-context premium (15). No batch endpoint or discount found. Background responses run asynchronously at the normal price (0). No SDK of Meta's own. The docs use the OpenAI and Anthropic SDKs against compatible endpoints, the same reading as StepFun (0). OpenAI-style error envelope with type and code, per-status fixes and named retryable codes (15).
Security & auth 14%17.5 11.2
Model reading. Bearer keys per team, named, shown once and revoked by deletion, with rotation advice. No scopes, read-only keys or per-key limits found (20 of 30). The terms say Meta will not use Content submitted to the Standard Services to train Meta Models, and training applies only to the -contributor model IDs a caller picks. Content may still be used to develop and improve safety and security systems (17 of 20). Retention is 'as needed' for the service, the law, flagged violations and safety review, with no period stated. Zero data retention for qualified accounts through sales, with flagged content kept up to 2 years (10 of 15). The usage dashboard shows tokens and requests per day by model, with no per-key or per-call log found (5 of 15). No security.txt on dev.meta.ai. Meta's bug bounty at bugbounty.meta.com is named in the Muse Code SDK's security policy, and a security commitments page describes TLS 1.2 or later, PCI-DSS card handling and an ISMS, with no named certification for the API (12 of 20).
Payments & pricing 10%12.5 2.5
No machine payment protocol (0). Per-token prices for Muse Wonder and Muse Spark, and per-image, per-hour and per-frame prices for the other models, published without a login (20). No free API allowance found. Billing needs a card, and Playground requests count towards usage (0). Browser sign-up with email, phone, Facebook, Google or GitHub (0).
Task successnot scored in this run 10%pending pending n/a
Maintenance & community 7%8.8 4.0
Model reading. Muse Wonder launched on 12 October 2026 (30). No deprecation policy or notice period found. All three Muse Spark versions are still served, so no retirement has tested one (0 of 12). Three dated launches in the last 90 days that we read, Muse Spark 1.2 on 5 August, Muse Code out of beta on 31 August and Muse Wonder on 12 October (8 of 8). No Model API changelog. A help centre with support tickets, answered 'typically within two business days' by Meta's own account, which we didn't test (8 of 15). No SDK of Meta's own for the API (0 of 15, 0 of 10).
Transparency & trusteditorial 41, provenance 63 7%8.8 4.5
Closed service with clear terms, under California law with AAA arbitration for Meta Platforms, Inc. and Irish law and courts for Meta Platforms Ireland Limited, with liability capped at the greater of 12 months of fees or $1,000. Muse Glimmer's open weights don't change the hosted service (15). The terms, the models page, the pricing page and the zero-retention help page agree that Standard content isn't used for training and Contributor content may be, but retention periods are not stated outside zero retention, and the privacy policy is Meta's general one (18 of 30). No deprecation policy or dated notices found, and the terms let Meta remove functionality without notice (0). A subprocessor list is linked from the terms but wasn't read, and no data locations were found (8 of 20).
Negative events≤15None recorded0
Total52.2 · D

Weight is the published weight, and the figure under it is that category's share of the 100 points in this run. A pending category has no score and adds nothing. What changes when it's scored.

Fix list 19 items, the biggest gain first

Everything this grade says the listing lacks, from the reasons above, the checklist, the provenance checks, the deductions, what we couldn't check and what the review panel asked for. Paste it into a coding agent working on Meta Model API, or have the agent fetch /fixes/meta-model-api.md. A fix counts at the next check, once it's public.

Markdown · JSON

Show it
# Fix list: Meta Model API

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/meta-model-api, the October 2026 research run, assessed 12 October 2026. Grade D, 52.2 out of 100.

This is everything the published grade says the listing lacks, the biggest possible gain to the total first. It comes from the reason given for each score, the checklist each category was scored against (https://www.anchorterminal.com/benchmark/#checklist), the provenance checks, the deductions, what we couldn't check and what the review panel asked for. A fix counts at the next check, once it's public.

For a coding agent working on Meta Model API: work through the items below in the product, its docs and its public pages. Each category gives the reason for its score, with the points each checklist item earned, and the checklist itself, so the gap is the items that earned less than their points. Change the product, not the wording, and keep a note of what you changed and where it's published.

## 1. Reliability, 40 out of 100, up to 12 more on the total

Why it scored 40: No status page with component history. The error guide's link to dev.meta.ai/status redirects to the home page, and `GET /v1/status` reports only the current state, `operational` when we called it on 12 October (0). No readable incident history (5). Rate limits published per team and per model, 3,000 RPM and 4,000,000 TPM for muse-wonder-1.0, 150 RPM for the contributor variants, 600 background submissions a minute (15). 429 and 503 carry Retry-After (60 seconds for `service_overloaded` and `backend_unavailable`), with backoff-with-jitter guidance, rate-limit headers on every token response and a documented mid-stream `server_shutting_down` event to retry (15). No SLA found, and the terms let Meta throttle or suspend access without notice (0). Muse Wonder is labelled a preview. Muse Spark 1.3 carries no preview label, but the API opened on 8 July 2026 as a public preview and we found no general-availability notice, so half (5 of 10, a departure from the all-or-nothing line).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-reliability):

Hosted APIs, MCP servers, models and platforms.

- 20, a public status page with component history (Statuspage, Instatus, BetterStack or the vendor's own).
- 0 to 30, the incident record for the last 90 days on that page. 30 for a clean record or trivial incidents only, 20 for minor incidents only, 10 for one major outage (an hour or more of a core API down, or errors across the board), 0 for several. 5 when there's no history we could read, and the note says so.
- 15, rate limits documented with numbers.
- 15, documented 429 or overload handling (Retry-After, backoff guidance), and idempotency keys or safe-retry guidance where writes are involved.
- 10, an SLA published for any paid tier.
- 10, the surface agents use is generally available, not beta or preview.

Local packages, SDKs, frameworks and stdio MCP servers.

- 20, installs from an official package with supported runtimes stated.
- 25, a public CI and test suite, passing on the default branch.
- 0 to 25, open crash or regression issues relative to activity (25 for few and handled, 0 for many, old and unanswered).
- 15, semver discipline and breaking changes called out in a changelog.
- 15, version 1.0 or later, or declared stable.

Protocols are read from their reference implementations, the public facilitators or servers, spec stability and test vectors.

## 2. Payments & pricing, 20 out of 100, up to 10 more on the total

Why it scored 20: No machine payment protocol (0). Per-token prices for Muse Wonder and Muse Spark, and per-image, per-hour and per-frame prices for the other models, published without a login (20). No free API allowance found. Billing needs a card, and Playground requests count towards usage (0). Browser sign-up with email, phone, Facebook, Google or GitHub (0).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-payments):

The published rubric, also on the [x402 page](https://www.anchorterminal.com/x402/).

- 40, a machine payment protocol (x402, MPP or L402) on the tool's own endpoints. 10 to 30 when it covers only some endpoints or only goes through a third party, and the note says which.
- 20, per-call or per-unit pricing published without a login. 10 for public plan-only pricing, 0 for "contact sales" or prices behind a login.
- 20, a free tier or trial that doesn't need a card.
- 20, autonomous onboarding, meaning an agent can get access without a person signing up in a browser (keyless use, x402, a programmatic key API).

Payment platforms and agent wallets rarely charge for their own API over a machine protocol, so the first line has steps for them, and the highest one that applies counts. 40 when x402, MPP or L402 runs on all their own endpoints, 30 when it runs on part of their own API, 25 when their merchants can accept one, 20 for running a facilitator, 15 for paying as a buyer, and 0 when the only protocol is their own. Merchant acceptance sits above a facilitator because the platform's own customers can charge agents through it, while a facilitator settles for sellers who wire up the protocol themselves. The counter-argument (a facilitator does more for the protocol as a whole) has a point. Each note says which step applied.

Open-source software you run yourself is scored on its hosted or paid option if it has one. A free, self-hosted package with nothing to buy gets 20, 20 and 20 for the last three lines, and 0 to 40 for the first only if it ships a payment protocol.

## 3. Schema & documentation, 60 out of 100, up to 6.5 more on the total

Why it scored 60: No OpenAPI or similar machine-readable contract found. The reference is Markdown pages with schema sections, and /openapi.json paths on dev.meta.ai return 404 (0). llms.txt at dev.meta.ai/llms.txt, and every docs page has a Markdown copy (10). The models page says when to choose Muse Wonder and when Muse Spark, and the tool-calling and structured-output guides state their limits, such as `tool_choice` only accepting `auto` and which schema keywords `strict` allows (16 of 20). JSON Schema tools and output, `reasoning_effort` an enum from minimal to max, a strict subset that returns 400 when violated, though `tool_choice` has one value (12 of 15). Curl, Python and TypeScript examples on each page and an error guide covering 400 to 504 with the error envelope, codes and a fix for each (15). Versioned model IDs (muse-spark-1.1 to 1.3, muse-wonder-1.0) and dated launch posts on the developer blog, but no API changelog (7 of 15).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-schema):

APIs and MCP servers.

- 25, a machine-readable contract (a public OpenAPI file or similar; for MCP, typed JSON Schema inputs on every tool).
- 10, llms.txt or Markdown docs served for agents.
- 0 to 20, descriptions that say what a tool is for, when to use it and when not to, read from the tool definitions in the source or the API reference.
- 0 to 15, typed inputs with enums, constraints and required fields, and no free-form JSON blobs.
- 0 to 15, examples and documented error responses.
- 15, versioning and a public changelog.

Models are read from the API reference, the OpenAPI file, llms.txt, the structured-output and tool-use docs and the model cards. Frameworks from docs a model can follow, typed interfaces, examples and the API reference.

## 4. Security & auth, 64 out of 100, up to 6.3 more on the total

Why it scored 64: Model reading. Bearer keys per team, named, shown once and revoked by deletion, with rotation advice. No scopes, read-only keys or per-key limits found (20 of 30). The terms say Meta will not use Content submitted to the Standard Services to train Meta Models, and training applies only to the `-contributor` model IDs a caller picks. Content may still be used to develop and improve safety and security systems (17 of 20). Retention is 'as needed' for the service, the law, flagged violations and safety review, with no period stated. Zero data retention for qualified accounts through sales, with flagged content kept up to 2 years (10 of 15). The usage dashboard shows tokens and requests per day by model, with no per-key or per-call log found (5 of 15). No security.txt on dev.meta.ai. Meta's bug bounty at bugbounty.meta.com is named in the Muse Code SDK's security policy, and a security commitments page describes TLS 1.2 or later, PCI-DSS card handling and an ISMS, with no named certification for the API (12 of 20).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-security):

- 0 to 30, the credential model. 30 for OAuth 2.1 with scopes, or scoped and revocable keys with rotation. 20 for plain revocable API keys. 10 for one all-powerful key. 10 off when a secret can travel in a URL query string as a documented option.
- 0 to 20, read-only or least-privilege modes, and confirmation or approval for destructive actions.
- 0 to 15, prompt-injection posture where the tool returns untrusted content (documented mitigations or guidance). A tool that returns no untrusted content gets 10.
- 0 to 15, audit logs or per-call visibility for the operator.
- 0 to 20, a security programme. security.txt or a disclosure policy, a bug bounty, SOC 2 or ISO 27001, advisories handled in public.

Models are read for retention, whether API data trains models (and whether that's off by default), zero-retention options and certifications. Frameworks for telemetry defaults, approval hooks, guardrails and sandboxing.

## 5. Maintenance & community, 46 out of 100, up to 4.7 more on the total

Why it scored 46: Model reading. Muse Wonder launched on 12 October 2026 (30). No deprecation policy or notice period found. All three Muse Spark versions are still served, so no retirement has tested one (0 of 12). Three dated launches in the last 90 days that we read, Muse Spark 1.2 on 5 August, Muse Code out of beta on 31 August and Muse Wonder on 12 October (8 of 8). No Model API changelog. A help centre with support tickets, answered 'typically within two business days' by Meta's own account, which we didn't test (8 of 15). No SDK of Meta's own for the API (0 of 15, 0 of 10).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-maintenance):

- 0 to 30, time since the last release, or the last published model or API change for a closed service. 30 within 30 days, 20 within 90, 10 within 180, 0 older.
- 20, at least three releases or dated changelog entries in the last 90 days.
- 0 to 25, responsiveness. Issues and pull requests answered on GitHub (the open issues and how recent the replies are). For closed services, a public changelog and a support or community channel that answers, 0 to 15.
- 15, presence in the official MCP registry under a verified namespace (MCP servers), or current official SDKs (APIs and models).
- 10, package health, current dependencies and CI.

Models are read for deprecation notice periods and model churn rather than release counts.

## 6. Transparency & trust, 52 out of 100, up to 4.2 more on the total

Made of editorial 41, provenance 63.

Why it scored 52: Closed service with clear terms, under California law with AAA arbitration for Meta Platforms, Inc. and Irish law and courts for Meta Platforms Ireland Limited, with liability capped at the greater of 12 months of fees or $1,000. Muse Glimmer's open weights don't change the hosted service (15). The terms, the models page, the pricing page and the zero-retention help page agree that Standard content isn't used for training and Contributor content may be, but retention periods are not stated outside zero retention, and the privacy policy is Meta's general one (18 of 30). No deprecation policy or dated notices found, and the terms let Meta remove functionality without notice (0). A subprocessor list is linked from the terms but wasn't read, and no data locations were found (8 of 20).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-transparency):

- 0 to 30, source availability and licence clarity. 30 for open source under an OSI licence, 15 for closed with clear terms, 0 for unclear terms.
- 0 to 30, data handling and retention statements that agree with each other (privacy policy, DPA, retention periods, subprocessors).
- 0 to 20, a deprecation policy or notices with dates.
- 0 to 20, telemetry disclosed with an opt-out (local software), or subprocessors and data locations disclosed (hosted).

The other half of Transparency and trust is the provenance score, computed from checked facts (below). The category score is the mean of the two.

Provenance checks not met in full (half of this category, computed from checked facts):

- Domain age: meta.ai, registered 2017-12-16 (8 years) (11 of 15)
- Privacy policy: published, but our reader couldn't read it (7 of 10)
- Status page: not found (0 of 10)
- Changelog: not found (0 of 10)
- security.txt: not found (0 of 10)

## 7. Agent ergonomics, 75 out of 100, up to 4.1 more on the total

Why it scored 75: Model reading of the checklist (tool use, structured output, caching, context, batch, SDKs, errors). Tool calls on all three endpoints, parallel calls, tool search with deferred loading, built-in web search and a computer-use tool, but `tool_choice` accepts only `auto`, so a call can't be forced or forbidden (15 of 20). Output constrained to the JSON Schema on every surface (15). Automatic prompt caching with no setup, and cached input at 5 per cent of the input price on Muse Wonder (15). 1,048,576-token context on Muse Wonder and every Muse Spark version, with no long-context premium (15). No batch endpoint or discount found. Background responses run asynchronously at the normal price (0). No SDK of Meta's own. The docs use the OpenAI and Anthropic SDKs against compatible endpoints, the same reading as StepFun (0). OpenAI-style error envelope with `type` and `code`, per-status fixes and named retryable codes (15).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-ergonomics):

- 0 to 25, context cost. For MCP, the number and size of the tool definitions (25 for ten or fewer compact tools, 15 for 11 to 30, 5 for more than 30, plus up to 10 back for toolsets, dynamic loading or read-only subsets). For APIs, whether responses can be sized (field selection, limits, summaries).
- 20, pagination, filtering and output-size controls.
- 20, actionable, documented error responses, codes and messages an agent can recover from.
- 20, idempotency or safe retries, and for MCP the `readOnlyHint` and `destructiveHint` annotations.
- 15, sensible defaults, few required parameters, and official SDKs in at least two languages.

Models are read for tool use, structured output, prompt caching, context length, batch and SDKs. Frameworks for how much code and how many defaults a tool-calling agent with MCP needs.

## What we couldn't check

What we couldn't read counted as absent. Publishing it on a page a plain HTTP fetch can read (not only in a browser) lets the next check count it.

- unchecked: whether an API call works before a card is added. The help centre says an admin adds a payment method to set up billing, and no free allowance is named
- unchecked: the subprocessor list at forwork.meta.com/legal/mfw-subprocessor-list/ and the Meta Global Processor Terms, not read, and the Meta Privacy Policy, which www.facebook.com's robots.txt asks readers like ours not to fetch
- unchecked: www.meta.ai/.well-known/security.txt. www.meta.ai's robots.txt disallows ClaudeBot from every path, so it wasn't requested
- Whether the API itself is generally available. The 8 July 2026 launch called it a public preview, the docs now label only Muse Wonder a preview, and no GA notice was found
- When Muse Spark 1.3 was released. The docs call it the latest version, and no dated page for it was found
- No authenticated call was made. That `muse-wonder-1.0` answers on api.meta.ai rests on the models, pricing and rate-limit pages, which list it
- No Meta Model API listing existed before. This listing covers the whole API with Muse Wonder as its flagship model, in line with the other model-vendor APIs in this category. llama-guard and llamafirewall are Meta's open-weight safety models and stay separate

## Weaknesses

- Muse Wonder is labelled a preview, and no deprecation policy or notice period was found
- No free API allowance found, and billing is set up with a card
- No status page with history. The docs' status link redirects to the home page, and `/v1/status` reports only the current state
- `tool_choice` accepts only `auto`, so a call can't be forced or ruled out
- No OpenAPI file, batch endpoint or Model API changelog found, and API keys have no scopes

## What costs an agent a turn today

The notes we give agents before they call it. Each one is a workaround an agent shouldn't need.

- Use `muse-wonder-1.0` for long multi-step work and `muse-spark-1.3` for cheaper, high-volume calls. Both take the same requests
- Keep personal or confidential data away from `-contributor` model IDs. Meta may train on that content
- Honour Retry-After on 429 and 503, which is 60 seconds for `service_overloaded`, and check `GET https://api.meta.ai/v1/status`, which needs no key
- Pass the key to the OpenAI SDK explicitly or set `OPENAI_API_KEY`. The SDK doesn't read `MODEL_API_KEY`
- Leave `tool_choice` at `auto`. The docs say `none` and `required` are not supported

## When it's done

Send what changed and where it's published as a dispute (https://www.anchorterminal.com/builders/#disputes, or `POST https://www.anchorterminal.com/api/v1/contact` with `"kind": "dispute"`). Disputes are answered in public, and the listing is checked again by the same checklist. Paying for an audit or a listing claim changes nothing here.

What we couldn't check

  • unchecked: whether an API call works before a card is added. The help centre says an admin adds a payment method to set up billing, and no free allowance is named
  • unchecked: the subprocessor list at forwork.meta.com/legal/mfw-subprocessor-list/ and the Meta Global Processor Terms, not read, and the Meta Privacy Policy, which www.facebook.com's robots.txt asks readers like ours not to fetch
  • unchecked: www.meta.ai/.well-known/security.txt. www.meta.ai's robots.txt disallows ClaudeBot from every path, so it wasn't requested
  • Whether the API itself is generally available. The 8 July 2026 launch called it a public preview, the docs now label only Muse Wonder a preview, and no GA notice was found
  • When Muse Spark 1.3 was released. The docs call it the latest version, and no dated page for it was found
  • No authenticated call was made. That muse-wonder-1.0 answers on api.meta.ai rests on the models, pricing and rate-limit pages, which list it
  • No Meta Model API listing existed before. This listing covers the whole API with Muse Wonder as its flagship model, in line with the other model-vendor APIs in this category. llama-guard and llamafirewall are Meta's open-weight safety models and stay separate

Sources 24

  1. Muse Wonder announcement, research blog research.meta.ai · seen 2026-10-12
  2. Muse Wonder model card (PDF) research.meta.ai · seen 2026-10-12
  3. Muse Wonder launch post, developer blog dev.meta.ai · seen 2026-10-12
  4. Muse Wonder model page dev.meta.ai · seen 2026-10-12
  5. docs index dev.meta.ai · seen 2026-10-12
  6. models, IDs, context and availability dev.meta.ai · seen 2026-10-12
  7. pricing and rate limits dev.meta.ai · seen 2026-10-12
  8. authentication dev.meta.ai · seen 2026-10-12
  9. quickstart dev.meta.ai · seen 2026-10-12
  10. API reference and Status endpoint dev.meta.ai · seen 2026-10-12
  11. error handling dev.meta.ai · seen 2026-10-12
  12. SDKs and libraries dev.meta.ai · seen 2026-10-12
  13. structured output dev.meta.ai · seen 2026-10-12
  14. tool calling dev.meta.ai · seen 2026-10-12
  15. Meta Model API Terms of Service, last updated 9 October 2026 dev.meta.ai · seen 2026-10-12
  16. Model Designation and Geographic Use Policy, last updated 12 October 2026 dev.meta.ai · seen 2026-10-12
  17. security commitments dev.meta.ai · seen 2026-10-12
  18. zero data retention dev.meta.ai · seen 2026-10-12
  19. sign-up dev.meta.ai · seen 2026-10-12
  20. billing set-up and how charges work dev.meta.ai · seen 2026-10-12
  21. contact support dev.meta.ai · seen 2026-10-12
  22. Muse Spark on the API, 8 July 2026 dev.meta.ai · seen 2026-10-12
  23. Muse Spark 1.2 and global access, 5 August 2026 dev.meta.ai · seen 2026-10-12
  24. unauthenticated status and models calls api.meta.ai · seen 2026-10-12

Probe metrics

Not measured yet. Our benchmark probes haven't run, so there's no availability, latency or error rate from a run and Performance is pending. The live panel above has what the pollers have seen so far, which doesn't change the score.

Pricing & changes

Pay per use $2.50 / 1k req Muse Wonder is $4.00 per million input tokens, $0.20 cached and $20.00 per million output tokens, Standard mode only (checked 2026-10-12). Muse Spark is $1.25, $0.15 and $4.25, or $0.10, $0.002 and $0.20 in Contributor mode, where Meta may train on the content. Billed in arrears to a card. No free allowance was found.

Prices

ItemPriceUnitNote
Muse Wonder input$4per 1M tokensStandard mode, muse-wonder-1.0. No long-context premium.
Muse Wonder cached input$0.20per 1M tokens
Muse Wonder output$20per 1M tokens
Muse Spark input$1.25per 1M tokensStandard mode, muse-spark-1.3, 1.2 and 1.1.
Muse Spark cached input$0.15per 1M tokens
Muse Spark output$4.25per 1M tokens
Muse Spark input, Contributor mode$0.10per 1M tokensMeta may use the content to train its models.
Muse Spark output, Contributor mode$0.20per 1M tokensCached input is $0.002 per million tokens.
Web search grounding$2.50per 1,000 requestsPer 1,000 search queries, on top of token cost.
Muse Image generated image$0.01per image

Compared across listings on the price index.

Recent changes

  • Latest release

Follow them as a feed at /feeds/tools/meta-model-api.xml, or this listing's score history at history.json.

Connect

First request

curl -X POST "https://api.meta.ai/v1/responses" \
  -H "Authorization: Bearer $MODEL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "muse-spark-1.3", "input": "What is the capital of France?"}'
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Is this your product? Link to this page from your own site or README, then tell us where. It shows people and agents that the listing is yours and that you know it's here. It never changes a grade, rank or review.

  1. Add the badge or a link

    Meta Model API on Anchor Terminal, D, 52.2/100
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Agents send the same to POST /api/v1/verify as {"slug": "meta-model-api", "url": "…"}, or call the verify_listing tool at /mcp. Ten checks an hour from one address. What we check. To announce the listing, get sharing assets for social media.

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