astrid-runtime/astrid · error

unsupported provider protocol

Error message

unsupported provider protocol {}

What it means

After decoding the stdin JSON into a StorageProviderRequestV1, run() checks protocol_version against STORAGE_PROVIDER_PROTOCOL_V1. A request stamped with any other version is rejected, since the v1 wire semantics are the only ones this provider implements.

Solutions

1. Set protocol_version to STORAGE_PROVIDER_PROTOCOL_V1 in the request.
2. Upgrade the provider binary to match the host's protocol version (or vice versa) so both agree on v1.
3. Read the actual version printed in the error message and compare against the host SDK's constant.
4. Update launch scripts/tests that hardcode the protocol version number.

Example fix

// before
let request = StorageProviderRequestV1 { protocol_version: 2, .. };
// after
let request = StorageProviderRequestV1 { protocol_version: STORAGE_PROVIDER_PROTOCOL_V1, .. };

// Before sending:
if request.protocol_version != STORAGE_PROVIDER_PROTOCOL_V1 {
    return Err(anyhow!("host speaks protocol {}, provider requires v1", request.protocol_version));
}

// Rust
fn is_provider_v1(r: &StorageProviderRequestV1) -> bool {
    r.protocol_version == STORAGE_PROVIDER_PROTOCOL_V1
}

// Host side
match run_provider(request).await {
    Err(e) if e.to_string().starts_with("unsupported provider protocol") => {
        // upgrade the provider binary or downgrade the request version, then retry
    }
    other => other?,
}

When it happens

Trigger: A host sends a StorageProviderRequestV1 whose protocol_version field is not STORAGE_PROVIDER_PROTOCOL_V1 — a newer host against an older provider, an old host against a provider that dropped legacy versions, or a handcrafted test request with the wrong constant.

Common situations: Partial upgrade: host package updated to a v2 protocol while the provider binary on the machine is still v1; vendored providers built from different branches; scripts with a hardcoded wrong version number.

Related errors

• FUSE callback probe protocol mismatch
• provider request exceeds limit
• this executable is an Astrid WinFsp provider, not an…
• WinFsp callback probe protocol mismatch
• build WinFsp callback filesystem

AI-assisted analysis of astrid-runtime/astrid@affd8760f4 (2026-09-09). Data as JSON: /api/errors/337b8a8fb81c9b3e. Report an issue: GitHub.

Appendix: source

Thrown at crates/astrid-storage-provider-winfsp/src/main.rs:102

async fn run() -> Result<StorageProviderResponseV1> {
    let arguments = std::env::args_os().skip(1).collect::<Vec<_>>();
    if arguments.as_slice() != [std::ffi::OsStr::new("--astrid-provider-stdio-v1")] {
        bail!("this executable is an Astrid WinFsp provider, not an interactive command");
    }
    let mut bytes = Vec::new();
    std::io::stdin()
        .lock()
        .take(MAX_REQUEST_BYTES + 1)
        .read_to_end(&mut bytes)
        .context("read provider request")?;
    if bytes.len() as u64 > MAX_REQUEST_BYTES {
        bail!("provider request exceeds limit");
    }
    let request: StorageProviderRequestV1 =
        serde_json::from_slice(&bytes).context("decode provider request")?;
    if request.protocol_version != STORAGE_PROVIDER_PROTOCOL_V1 {
        bail!("unsupported provider protocol {}", request.protocol_version);
    }
    let request_id = request.request_id;
    let outcome = match execute(request).await {
        Ok(success) => StorageProviderOutcomeV1::Success(success),
        Err(error) => StorageProviderOutcomeV1::Failure(StorageProviderFailureV1 {
            code: "provider-operation".to_owned(),
            message: error.to_string().chars().take(4096).collect(),
        }),
    };
    Ok(StorageProviderResponseV1 {
        protocol_version: STORAGE_PROVIDER_PROTOCOL_V1,
        request_id,
        provider: StorageProviderIdentityV1 {
            name: PROVIDER_NAME.to_owned(),
            version: env!("CARGO_PKG_VERSION").to_owned(),
            capabilities: vec![
                StorageProviderCapabilityV1::PrincipalView,
                StorageProviderCapabilityV1::FleetView,

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