---
title: "Amazon Bedrock"
description: "Route Fabro models through Amazon Bedrock with SigV4 or API-key auth"
---

[Amazon Bedrock](https://aws.amazon.com/bedrock/) hosts Anthropic, Amazon, Meta, Mistral, DeepSeek, Qwen, Moonshot, Z.AI, MiniMax, NVIDIA, and OpenAI open-weight models behind one AWS endpoint. Fabro ships a disabled `bedrock` provider entry with a curated model catalog over Bedrock's unified Converse API, so you can opt in from `settings.toml` without changing Fabro code.

## Prerequisites

- An AWS account with [Bedrock model access](https://docs.aws.amazon.com/bedrock/latest/userguide/model-access.html) granted for the models you want (see [Model access and approvals](#model-access-and-approvals))
- Either a [Bedrock API key](https://docs.aws.amazon.com/bedrock/latest/userguide/api-keys.html) or working AWS credentials (environment keys, profile, IMDS, IRSA, SSO)

## Model access and approvals

Access is granted per Region and varies by model family — enabling the provider in Fabro is necessary but not sufficient.

- **IAM.** Converse and ConverseStream have no dedicated IAM actions; they're authorized by `bedrock:InvokeModel` and `bedrock:InvokeModelWithResponseStream`. A Bedrock API key additionally needs `bedrock:CallWithBearerToken`.
- **Anthropic (Claude) models** require a one-time use-case submission in the Bedrock console (**Model access**) before first use, and the grant is **per Region** — approval in `us-east-1` does not cover `us-east-2`. An un-approved Region returns `AccessDeniedException`.
- **Third-party models** (OpenAI gpt-oss, DeepSeek, Qwen, Moonshot, Z.AI, MiniMax, NVIDIA) auto-enable on first call, which needs `aws-marketplace:Subscribe` and `aws-marketplace:ViewSubscriptions` on the calling principal. The first call may take a moment while the subscription activates.
- **Claude Fable 5 / Mythos-class** models additionally require opting into data sharing via the [Data Retention API](https://docs.aws.amazon.com/bedrock/latest/userguide/data-retention.html) (`provider_data_share`, 30-day retention) **before** they can be invoked. With the account/project on the `default` retention mode, Converse rejects the request with *"data retention mode 'default' is not available for this model."*

## Enable the provider

Add the provider override to `~/.fabro/settings.toml`:

```toml title="settings.toml"
_version = 1

[llm.providers.bedrock]
base_url = "https://bedrock-runtime.us-east-1.amazonaws.com"
enabled = true
```

The SigV4 signing region is derived from `base_url` — change it to your Region's endpoint (`https://bedrock-runtime.<region>.amazonaws.com`, FIPS and China endpoints included).

## Configure credentials

Two auth modes, tried in order:

**Bedrock API key** (simplest): store the key and Fabro sends it as a bearer token. The key is read from either `AWS_BEARER_TOKEN_BEDROCK` (AWS's canonical name, also honored by the AWS SDKs and CLI) or `BEDROCK_API_KEY` (the `<PROVIDER>_API_KEY` convention) — use whichever you prefer.

```bash
fabro secret set AWS_BEARER_TOKEN_BEDROCK bedrock-api-key-...
# or, equivalently
fabro secret set BEDROCK_API_KEY bedrock-api-key-...
```

Runs read the bearer token from the vault only. Workers start from a cleared environment and the bearer token is not on the inherited allowlist, so exporting it in the server's shell has no effect on runs. `fabro exec` and direct `fabro-llm` SDK usage do read it from process env.

**AWS SigV4** (IAM-scoped): with no API key configured, Fabro signs each request using the AWS default credential chain — environment keys, shared profile, EC2/ECS instance roles, IRSA/web identity, SSO. Expiring session credentials refresh automatically.

The order is fixed by lithos-llm: `AWS_BEARER_TOKEN_BEDROCK`, then `BEDROCK_API_KEY`, then the AWS default chain. Each name is read from the process environment first and the server vault (`fabro secret set`) second — so on a server, prefer `secret set`. To select a non-default AWS profile for SigV4, set `AWS_PROFILE` (it, and the rest of the AWS credential-chain variables, are passed through to workflow workers).

<Warning>
**Bearer-vs-SigV4 precedence.** Because the bearer key is tried before SigV4, setting `AWS_BEARER_TOKEN_BEDROCK` makes the `bedrock` (Converse) provider authenticate with that key too — not just the `bedrock-openai` mantle provider below. If your key is valid only for mantle (it lacks `bedrock:InvokeModel*` on the runtime), every Converse model then fails with *"Authentication failed."* Use a key that covers both surfaces, or keep Converse on SigV4 by leaving both Bedrock secret names unset and enabling only `bedrock`.
</Warning>

## Included models

The built-in catalog curates Converse-capable models, using cross-region inference profile ids (`us.`/`global.` prefixes) where on-demand access requires them:

| Fabro model ID | Notes |
| --- | --- |
| `us.anthropic.claude-sonnet-4-6` | Provider default; Anthropic cache billing |
| `us.anthropic.claude-opus-4-8` | Anthropic cache billing |
| `us.anthropic.claude-haiku-4-5` | Provider small default |
| `us.anthropic.claude-fable-5` | Frontier; sampling params pinned by Bedrock (Fabro drops `temperature`/`top_p` automatically); requires the account-level `provider_data_share` data-sharing opt-in (see [Model access](#model-access-and-approvals)) |
| `openai.gpt-oss-120b`, `openai.gpt-oss-20b` | OpenAI open-weights |
| `amazon.nova-2-lite` | Vision |
| `meta.llama4-maverick` | Vision |
| `mistral.mistral-large-3`, `mistral.devstral-2` | |
| `deepseek.v3-2` | |
| `moonshotai.kimi-k2.5`, `zai.glm-5` | |
| `minimax.minimax-m2.5`, `nvidia.nemotron-3-super` | |

Any other Converse-capable Bedrock model can be added under `[llm.providers.bedrock.models."<model-id>"]` with the Bedrock model or inference-profile id as `api_model`.

Not included on this provider: Claude Mythos 5 (Anthropic-Messages-only on `bedrock-mantle`, limited preview). OpenAI's frontier models live on the companion `bedrock-openai` provider below.

## OpenAI frontier models (GPT-5.5 / GPT-5.4)

GPT-5.5 and GPT-5.4 on Bedrock are served only by the `bedrock-mantle` endpoint's OpenAI Responses API — a different surface than Converse. Fabro ships a companion `bedrock-openai` provider for them: the same AWS account and `AWS_BEARER_TOKEN_BEDROCK` key, pointed at the mantle endpoint over the OpenAI dialect.

```toml title="settings.toml"
[llm.providers.bedrock-openai]
enabled = true
# regional: change to https://bedrock-mantle.<region>.api.aws/openai/v1
```

```bash
fabro model test --model openai.gpt-5.5
```

Auth on this provider is Bedrock-API-key only (mantle SigV4 uses a different signing name than the runtime endpoint). Fabro always sends `store: false`, so nothing is retained under mantle's default 30-day response storage.

## Use Bedrock models

```bash
fabro model list --provider bedrock
fabro model test --model us.anthropic.claude-sonnet-4-6
fabro run workflow.fabro --model deepseek.v3-2
```

## Prompt caching

Claude models cache automatically when the catalog row declares `prompt_cache`: Fabro places Converse `cachePoint` blocks after the system prompt, the tool definitions, and the conversation prefix — the same placement as the direct Anthropic provider. Cache reads and writes price at the row's `cached_input_usd_micros_per_million` and `cache_write_usd_micros_per_million` rates.

## Converse extensions

Bedrock-specific request fields pass through verbatim via `provider_options.bedrock` on API/SDK requests — the keys merge into the top level of the Converse envelope:

```json
{
  "model": "us.anthropic.claude-sonnet-4-6",
  "provider_options": {
    "bedrock": {
      "additionalModelRequestFields": { "top_k": 200 },
      "guardrailConfig": { "guardrailIdentifier": "gr-abc", "guardrailVersion": "1" },
      "serviceTier": { "type": "flex" }
    }
  }
}
```

## Troubleshooting

**"no AWS credentials provider found"** — Neither an API key nor any AWS chain source resolved. Set `AWS_BEARER_TOKEN_BEDROCK` (or `BEDROCK_API_KEY`), or configure standard AWS credentials.

**`AccessDeniedException` / 403** — The IAM principal lacks `bedrock:InvokeModel*` for the model, or model access has not been granted in the Bedrock console for your Region (Claude needs the per-Region use-case approval; third-party models need `aws-marketplace:Subscribe`).

**"Authentication failed: Please make sure your API Key is valid."** — A Bedrock API key was sent but rejected by the runtime. Common cause: a mantle-scoped key used against Converse — see the bearer-vs-SigV4 [warning above](#configure-credentials). Verify the key is valid for `bedrock-runtime` in this Region, or pin Converse to `aws_sigv4`.

**"data retention mode 'default' is not available for this model"** — Fable 5 / Mythos-class models require opting into data sharing first; see [Model access and approvals](#model-access-and-approvals).

**"The provided model identifier is invalid"** — The wire id sent to Bedrock isn't a recognized model or inference-profile id. Set an explicit `api_model` (from `aws bedrock list-inference-profiles`) on the model entry.

**`ValidationException` mentioning on-demand throughput** — The model requires an inference-profile id; use the `us.`/`global.`-prefixed id from the catalog rather than the bare model id.

**`ValidationException` mentioning maximum tokens** — The requested `max_tokens` exceeds the model's per-request output cap; lower the model's `max_output` to the documented limit.

**`ThrottlingException`** — Account-level Bedrock quota; consider cross-region inference profiles or a quota increase.

## Further reading

<Columns cols={2}>
  <Card title="Models" icon="microchip" href="/core-concepts/models">
    How Fabro routes model IDs, providers, and fallbacks.
  </Card>
  <Card title="Settings Configuration" icon="gear" href="/reference/user-configuration">
    Full reference for provider settings and provider-scoped model offerings.
  </Card>
</Columns>