OpenRouter

OpenRouter is an aggregator that fronts hundreds of models behind one OpenAI-compatible API. Fabro ships a disabled openrouter provider entry with a curated model catalog, so you can opt in from settings.toml without changing Fabro code.

Prerequisites

An OpenRouter account with credit for paid models
An API key from openrouter.ai/keys

Enable the provider

Fabro runs execute through a Fabro server. Add the provider override to the settings file used by that server. For a local server, this is usually ~/.fabro/settings.toml; for a remote deployment, update the server host’s Fabro settings.

settings.toml

_version = 1

[llm.providers.openrouter]
enabled = true

Configure credentials

Store the key in the target Fabro server vault:

fabro provider login --provider openrouter

# For a non-default remote server:
fabro provider login --server https://your-fabro.example --provider openrouter

# Or set the vault token directly:
fabro secret set OPENROUTER_API_KEY sk-or-v1-...
fabro secret --server https://your-fabro.example set OPENROUTER_API_KEY sk-or-v1-...

Direct SDK usage outside a Fabro server can use an env-backed credential source explicitly:

export OPENROUTER_API_KEY=sk-or-v1-...

Included models

The built-in catalog curates frontier and open-weights models under vendor-namespaced IDs:

Fabro model ID	Notes
`anthropic/claude-opus-4-7`	Claude via OpenRouter, Anthropic-style cache billing
`anthropic/claude-sonnet-4-6`	Provider default
`anthropic/claude-haiku-4-5`	Provider small default
`openai/gpt-5.4`, `openai/gpt-5.5`
`google/gemini-3.1-pro-preview`, `google/gemini-3.5-flash`
`deepseek/deepseek-v4-pro`, `deepseek/deepseek-v4-flash`
`moonshotai/kimi-k2.6`, `qwen/qwen3-coder`, `qwen/qwen3.6-flash`
`z-ai/glm-4.6`, `minimax/minimax-m2.7`, `xiaomi/mimo-v2.5-pro`
`nvidia/nemotron-3-super-120b-a12b`, `mistralai/devstral-2512`

Any other OpenRouter model can be added as a settings model entry with provider = "openrouter" and the OpenRouter slug as api_id:

settings.toml

[llm.models."meta-llama/llama-4-maverick"]
provider = "openrouter"
api_id = "meta-llama/llama-4-maverick"
display_name = "Llama 4 Maverick"
family = "llama-4"

[llm.models."meta-llama/llama-4-maverick".limits]
context_window = 1000000

[llm.models."meta-llama/llama-4-maverick".features]
tools = true
vision = false
reasoning = false

Use OpenRouter models

fabro model list --provider openrouter
fabro model test --model anthropic/claude-sonnet-4-6
fabro run workflow.fabro --model deepseek/deepseek-v4-flash

When targeting a non-default remote server, pass the same --server value to verification commands:

fabro model list --server https://your-fabro.example --provider openrouter
fabro model test --server https://your-fabro.example --model anthropic/claude-sonnet-4-6

In workflow stylesheets:

workflow.fabro

digraph Example {
    graph [
        model_stylesheet="
            * { model: anthropic/claude-sonnet-4-6; }
        "
    ]

    start [shape=Mdiamond, label="Start"]
    work  [label="Work", prompt="Use the configured OpenRouter model."]
    exit  [shape=Msquare, label="Exit"]

    start -> work -> exit
}

Cost telemetry

Every OpenRouter response includes an inline usage.cost with authoritative USD billing. Fabro surfaces it as cost_usd with cost_source = "authoritative" on completion responses. Other providers populate the same fields from catalog price estimates with cost_source = "estimated". The catalog prices on OpenRouter model rows are best-effort estimates used only before the authoritative figure arrives (for example, mid-stream rollups).

Provider routing

OpenRouter’s provider routing preferences pass through verbatim via provider_options.openrouter on API/SDK requests — the keys merge into the top level of the request body:

{
  "model": "anthropic/claude-sonnet-4-6",
  "provider_options": {
    "openrouter": {
      "provider": { "sort": "throughput", "data_collection": "deny" },
      "models": ["anthropic/claude-sonnet-4.6", "deepseek/deepseek-v4-pro"]
    }
  }
}

Attribution headers

Fabro does not send OpenRouter’s optional attribution headers (HTTP-Referer, X-Title) by default, so self-hosted installations stay anonymous on OpenRouter’s public app leaderboard. To opt in:

settings.toml

[llm.providers.openrouter.extra_headers]
"HTTP-Referer" = { literal = "https://your-site.example" }
"X-Title" = { literal = "Your App" }

Troubleshooting

“No API key configured” — Set the key on the target server with fabro provider login --provider openrouter or fabro secret set OPENROUTER_API_KEY .... For direct SDK usage outside a Fabro server, export OPENROUTER_API_KEY in the invoking shell. “provider ‘openrouter’ is not configured in the server model catalog” — Confirm the server host’s settings.toml has [llm.providers.openrouter] with enabled = true. Fabro live-reloads settings.toml within a few seconds; after that, fabro model list --provider openrouter against the same server should show the enabled catalog. 402 / insufficient credits — Paid OpenRouter models require prepaid credit; check your balance at openrouter.ai/credits. Unknown model — Confirm the model’s api_id matches an OpenRouter slug exactly (including the vendor prefix), then run fabro model test --model <fabro-model-id>.

Models

How Fabro routes model IDs, providers, and fallbacks.

Settings Configuration

Full reference for [llm.providers.<id>] and [llm.models.<id>].

Getting Started

Core Concepts

Defining Workflows

Executing Workflows

Human Tools

Agents

Integrations

Reference

Prerequisites

Enable the provider

Configure credentials

Included models

Use OpenRouter models

Cost telemetry

Provider routing

Attribution headers

Troubleshooting

Further reading

Models

Settings Configuration

​Prerequisites

​Enable the provider

​Configure credentials

​Included models

​Use OpenRouter models

​Cost telemetry

​Provider routing

​Attribution headers

​Troubleshooting

​Further reading

Models

Settings Configuration

Prerequisites

Enable the provider

Configure credentials

Included models

Use OpenRouter models

Cost telemetry

Provider routing

Attribution headers

Troubleshooting

Further reading