For the complete documentation index, see llms.txt. This page is also available as Markdown.

Changelog

New updates and improvements

Added

Model Playground: Image & Video — Added dedicated Image and Video Playgrounds to experiment with multimodal models directly from the browser. Generate images and videos, compare model outputs, and iterate without writing any code.

Improved

Prompt Library — Optimize any saved prompt version directly from Prompt Library. Prompt Optimizations now creates a new version automatically, preserving the original while making it easy to review and promote improvements.

Prompt Comparison with Samples — Compare the original and optimized prompt side-by-side using sample inputs before promoting a new version. Quickly validate improvements and understand how prompt changes affect model outputs.

https://docs.fastrouter.ai/prompt-library

Added

BytePlus Provider — Added support for BytePlus-hosted models. FastRouter automatically handles BytePlus' custom pricing flow, including providers that return pricing information asynchronously, ensuring accurate cost tracking and billing.

New Video & Multimodal Models — Added support for the latest image, video, and reasoning models, including x-ai/grok-imagine-video, GLM 5.2, Kimi Code 2.7, and Minimax M3.

https://fastrouter.ai/models?order=newest

Added

MCP Server Templates — Added pre-configured templates for popular MCP servers, eliminating the need to manually enter server configuration values. Connect common tools in just a few clicks while retaining the flexibility to customize settings when needed.

https://docs.fastrouter.ai/mcp-gateway

Added

Prompt Library — Write, store, version, and optimize prompts in one place and reference them by ID in API calls, so prompt changes ship without a code deploy. Mark any version as Production to serve it to all live requests, and roll back instantly by promoting an earlier version. Optimize — Refine a stored prompt with Prompt Optimizations and save the result as a tracked, optimized version, with Compare to diff versions before promoting. Variables — Insert {{curly braces}} placeholders in a prompt and fill them per request via the variables field.

https://docs.fastrouter.ai/prompt-library

Added

Free Models (:free) — Append :free to a supported model ID (e.g. sarvam/sarvam-105b:free) to route requests at no cost, with the suffix stripped transparently before reaching the provider. Available to all orgs regardless of billing status. Per-model daily quota — 10 requests per org per day, tracked independently per model and reset daily at UTC midnight; paid orgs consume free quota rather than billing credits.

https://docs.fastrouter.ai/explore-features/free-models-free

Added

Support for non-Claude models via Anthropic Messages format — Route Claude Code requests to OpenAI, DeepSeek, and other FastRouter-supported providers using the same Anthropic-compatible interface Universal model access in Claude Code — Launch Claude Code with any FastRouter-supported model using the --model flag, without changing tooling or workflows

https://docs.fastrouter.ai/integrations/claude-code

Added

Bring Your Own Keys (BYOK) for external providers — Attach your own API credentials from supported LLM providers directly to FastRouter while preserving your negotiated pricing Custom model provisioning — Register fine-tuned or privately hosted models with custom endpoints, pricing metadata, and API compatibility mappings Advanced endpoint configuration — Override provider base URLs with OpenAI-, Anthropic-, or Gemini-compatible formats, plus support for custom authentication headers Granular model enablement — Enable or disable individual catalog models per integration and map custom models to provider-specific endpoints Integrated routing visibility — Reference integrations via Provider Slug across Virtual Models, Gateway Configs, and Activity Logs for full routing traceability https://docs.fastrouter.ai/add-external-keys-byok

Added

Video Evaluations for AI-generated content — Automatically assess video outputs at scale using LLM-based judges, with scoring across motion fidelity, audio-visual sync, cinematic quality, and prompt adherence

Seamless log-based dataset creation — Import video generation logs directly from FastRouter activity with filtering, sampling, and zero manual uploads

Unified evaluation infrastructure — Use the same Custom Evaluations setup as text and image evals, including shared judge configuration, scoring rubrics, and dashboards

Multimodal LLM judging — Leverage capable video-aware models to evaluate outputs with structured reasoning across multiple quality dimensions

Deep-dive result analysis — Access per-video judge reasoning, aggregated performance metrics, and cost/latency insights in a single view

https://docs.fastrouter.ai/video-evaluations

Added

Flex Pricing for Vertex AI and Google AI Studio models — Access supported models at up to 50% lower cost by using provider Flex inference tiers, ideal for batch jobs, background workloads, and latency-tolerant applications

Zero code-change activation — Append :flex to any supported model ID (for example google/gemini-3.1-pro-preview:flex) while keeping the same API key, endpoint, and request payload

Provider-native Flex routing — FastRouter automatically routes requests to the provider’s discounted Flex tier, with support for provider pinning to ensure correct execution paths

Built for async and cost-sensitive workloads — Recommended for summarisation pipelines, data extraction, classification, eval runs, scheduled jobs, and large-scale preprocessing tasks where response speed is less critical

Model Catalog Flex visibility — View supported Flex-enabled models and pricing directly in the model catalog, with per-model availability across providers

https://docs.fastrouter.ai/flex-pricing

Added

Flex Pricing for OpenAI models — Access supported models at up to 50% lower cost by using provider Flex inference tiers, ideal for batch jobs, background workloads, and latency-tolerant applications

Zero code-change activation — Append :flex to any supported model ID (for example openai/gpt-5.4-nano:flex) while keeping the same API key, endpoint, and request payload

Provider-native Flex routing — FastRouter automatically routes requests to the provider’s discounted Flex tier, with support for provider pinning to ensure correct execution paths

Built for async and cost-sensitive workloads — Recommended for summarisation pipelines, data extraction, classification, eval runs, scheduled jobs, and large-scale preprocessing tasks where response speed is less critical

Model Catalog Flex visibility — View supported Flex-enabled models and pricing directly in the model catalog, with per-model availability across providers

https://docs.fastrouter.ai/flex-pricing

Added

Prompt Optimizations (GEPA-powered) — Automatically improve system prompts using FastRouter’s Genetic-Pareto optimization engine with iterative reflection, mutation, and scoring

Run prompt experiments from your own data — Import datasets from files or Activity Logs, evaluate against custom metrics, and compare optimized prompts against baseline performance

LLM-as-a-Judge evaluations — Score prompts across metrics like Accuracy, Helpfulness, Safety, Completeness, or your own custom criteria using a shared evaluator model

Optimization Insights — Review improvement %, final scores, accepted iterations, and the full optimized prompt in a dedicated results view

https://docs.fastrouter.ai/prompt-optimizations

Added

MCP Gateway — Register any MCP-compatible server (GitHub, Linear, Gmail, or your own APIs) and expose its tools to any model routed through FastRouter, with centralized credential management, project-level scoping, and selective tool exposure

OAuth 2.0 & Static Header authentication for MCP servers — Securely store and inject credentials server-side across all tool calls, with support for No Auth, Static Header, and full OAuth 2.0 authorization code flow

Auto-execution mode — Set auto_execute_tools: true to let FastRouter handle the complete tool-call loop and return a final text response directly, with a configurable max_tool_rounds cap (maximum 5)

https://docs.fastrouter.ai/mcp-gateway

Added

Priority Routing — Route requests through models in a fixed priority order, with automatic sequential fallback for deterministic, predictable routing

Category-Based Routing — Direct requests to different model groups based on detected prompt category, with per-category sub-strategies and a configurable default fallback

https://docs.fastrouter.ai/explore-features/virtual-model-aliases

Added

Tracing (W3C traceparent support) — Group multiple LLM API calls into a single trace with ordered spans

Traces view in Activity — Visualize execution timelines, latency, tokens, and cost across spans

https://docs.fastrouter.ai/tracing

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