fix(MCP): decode resource content by alexhancock · Pull Request #7155 · block/goose

alexhancock · 2026-02-11T16:35:55Z

Decodes resource content when base64 encoded blobs are included so goose can make sense of the content

Copilot

Pull request overview

This PR fixes MCP resource handling by decoding base64-encoded BlobResourceContents into usable text so goose can correctly surface downloaded resource content (e.g., from the GitHub MCP server).

Changes:

Added extract_text_from_resource to decode base64 blobs and fall back to a binary placeholder when content isn’t valid UTF-8.
Updated OpenAI message formatting to use the new extraction helper for RawContent::Resource.
Updated conversation message conversion to use the same helper and added focused unit tests.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
crates/goose/src/providers/utils.rs	Introduces base64-decoding helper for MCP resources and adds unit tests.
crates/goose/src/providers/formats/openai.rs	Uses the helper to convert MCP resource content into text for tool responses.
crates/goose/src/conversation/message.rs	Uses the helper when converting resource content into `MessageContent`.

Copilot · 2026-02-11T16:39:23Z

crates/goose/src/providers/utils.rs

The byte count in the binary placeholder uses blob.len() (base64 string length) rather than the decoded byte length, so the reported size will be misleading; capture bytes.len() before String::from_utf8 and use that instead.

Suggested change

Ok(bytes) => match String::from_utf8(bytes) {

Ok(text) => text,

Err(_) => {

let mime = mime_type

.as_ref()

.map(|m| m.as_str())

.unwrap_or("application/octet-stream");

format!("[Binary content ({}) - {} bytes]", mime, blob.len())

}

},

Ok(bytes) => {

let byte_len = bytes.len();

match String::from_utf8(bytes) {

Ok(text) => text,

Err(_) => {

let mime = mime_type

.as_ref()

.map(|m| m.as_str())

.unwrap_or("application/octet-stream");

format!("[Binary content ({}) - {} bytes]", mime, byte_len)

}

}

}

Copilot · 2026-02-11T16:39:24Z

crates/goose/src/conversation/message.rs

 use crate::conversation::tool_result_serde;
 use crate::mcp_utils::ToolResult;
+use crate::providers::utils::extract_text_from_resource;
 use crate::utils::sanitize_unicode_tags;


conversation/message.rs now imports crate::providers::utils, creating a bidirectional coupling (providers already depend on conversation::message); consider moving extract_text_from_resource to a neutral module (e.g., crate::utils/mcp_utils) to keep the core message model provider-agnostic.

This seems like a good idea to ,e

Copilot

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

Copilot · 2026-02-11T21:05:11Z

crates/goose/src/providers/formats/openai.rs

                                    RawContent::Resource(resource) => {
-                                        let text = match &resource.resource {
-                                            ResourceContents::TextResourceContents {
-                                                text, ..
-                                            } => text.clone(),
-                                            _ => String::new(),
-                                        };
+                                        let text = extract_text_from_resource(&resource.resource);
                                        tool_content.push(Content::text(text));
                                    }


This change alters OpenAI tool-response formatting for RawContent::Resource (now including decoded blob text), but there’s no test covering this path; add a unit test that builds a tool result containing a blob resource and asserts the formatted payload includes the decoded text.

Copilot · 2026-02-11T21:05:11Z

crates/goose/src/conversation/message.rs

            PromptMessageContent::Resource { resource } => {
-                // For resources, convert to text content with the resource text
-                match &resource.resource {
-                    ResourceContents::TextResourceContents { text, .. } => {
-                        MessageContent::text(text.clone())
-                    }
-                    ResourceContents::BlobResourceContents { blob, .. } => {
-                        MessageContent::text(format!("[Binary content: {}]", blob.clone()))
-                    }
-                }
+                MessageContent::text(extract_text_from_resource(&resource.resource))
            }


The previous test coverage for blob resources in From<PromptMessage> was removed, and the new behavior (base64-decoding blob resources into text) isn’t asserted anywhere in this module; add/restore a test that constructs a BlobResourceContents with base64-encoded UTF-8 and verifies the resulting MessageContent::Text is the decoded text.

Copilot · 2026-02-11T21:05:11Z

crates/goose/src/mcp_utils.rs

The byte count in the binary placeholder is computed with blob.len(), which is the base64 string length rather than the decoded byte length; use the decoded bytes.len() (and ideally assert the exact byte count in the unit test) to avoid misleading output.

codefromthecrypt

cool I like centralized code

codefromthecrypt · 2026-02-12T01:44:24Z

crates/goose/src/mcp_utils.rs

since this is predictable and also doesn't include the actual raw bytes, just hte type and length, I think we can assert thew whole result right? this would also allow us to catch any incorrect length

DOsinga · 2026-02-12T10:29:01Z

crates/goose/src/conversation/message.rs

 use crate::conversation::tool_result_serde;
 use crate::mcp_utils::ToolResult;
+use crate::providers::utils::extract_text_from_resource;
 use crate::utils::sanitize_unicode_tags;


This seems like a good idea to ,e

DOsinga · 2026-02-12T13:38:47Z

crates/goose/src/mcp_utils.rs

can we do a #test_case for this? doesn't help much, but easier to read

…provenance * origin/main: (68 commits) Upgraded npm packages for latest security updates (#7183) docs: reasoning effort levels for Codex provider (#6798) Fix speech local (#7181) chore: add .gooseignore to .gitignore (#6826) Improve error message logging from electron (#7130) chore(deps): bump jsonwebtoken from 9.3.1 to 10.3.0 (#6924) docs: standalone mcp apps and apps extension (#6791) workflow: auto-update cli-commands on release (#6755) feat(apps): Integrate AppRenderer from @mcp-ui/client SDK (#7013) fix(MCP): decode resource content (#7155) feat: reasoning_content in API for reasoning models (#6322) Fix/configure add provider custom headers (#7157) fix: handle keyring fallback as success (#7177) Update process-wrap to 9.0.3 (9.0.2 is yanked) (#7176) feat: support extra field in chatcompletion tool_calls for gemini openai compat (#6184) fix: replace panic with proper error handling in get_tokenizer (#7175) Lifei/smoke test for developer (#7174) fix text editor view broken (#7167) docs: White label guide (#6857) Add PATH detection back to developer extension (#7161) ... # Conflicts: # .github/workflows/nightly.yml

* origin/main: (21 commits) nit: show dir in title, and less... jank (#7138) feat(gemini-cli): use stream-json output and re-use session (#7118) chore(deps): bump qs from 6.14.1 to 6.14.2 in /documentation (#7191) Switch jsonwebtoken to use aws-lc-rs (already used by rustls) (#7189) chore(deps): bump qs from 6.14.1 to 6.14.2 in /evals/open-model-gym/mcp-harness (#7184) Add SLSA build provenance attestations to release workflows (#7097) fix save and run recipe not working (#7186) Upgraded npm packages for latest security updates (#7183) docs: reasoning effort levels for Codex provider (#6798) Fix speech local (#7181) chore: add .gooseignore to .gitignore (#6826) Improve error message logging from electron (#7130) chore(deps): bump jsonwebtoken from 9.3.1 to 10.3.0 (#6924) docs: standalone mcp apps and apps extension (#6791) workflow: auto-update cli-commands on release (#6755) feat(apps): Integrate AppRenderer from @mcp-ui/client SDK (#7013) fix(MCP): decode resource content (#7155) feat: reasoning_content in API for reasoning models (#6322) Fix/configure add provider custom headers (#7157) fix: handle keyring fallback as success (#7177) ...

alexhancock requested review from DOsinga, jamadeo and katzdave February 11, 2026 16:35

alexhancock marked this pull request as ready for review February 11, 2026 16:36

Copilot AI review requested due to automatic review settings February 11, 2026 16:36

Copilot started reviewing on behalf of alexhancock February 11, 2026 16:36 View session

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alexhancock force-pushed the alexhancock/decode-resource-content branch from 462c31e to 2ce9841 Compare February 11, 2026 17:16

Copilot AI review requested due to automatic review settings February 11, 2026 21:01

alexhancock force-pushed the alexhancock/decode-resource-content branch from 2ce9841 to 61e7976 Compare February 11, 2026 21:01

Copilot started reviewing on behalf of alexhancock February 11, 2026 21:01 View session

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codefromthecrypt approved these changes Feb 12, 2026

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DOsinga approved these changes Feb 12, 2026

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fix(MCP): decode resource content

5592eee

alexhancock force-pushed the alexhancock/decode-resource-content branch from 61e7976 to 5592eee Compare February 12, 2026 15:03

alexhancock added this pull request to the merge queue Feb 12, 2026

Merged via the queue into main with commit 5d93967 Feb 12, 2026
29 of 32 checks passed

alexhancock deleted the alexhancock/decode-resource-content branch February 12, 2026 16:02

github-actions bot mentioned this pull request Feb 12, 2026

chore(release): release version 1.24.0 (minor) #7102

Closed

BrewTestBot mentioned this pull request Feb 12, 2026

block-goose-cli 1.24.0 Homebrew/homebrew-core#267289

Merged

github-actions bot mentioned this pull request Feb 17, 2026

chore(release): release version 1.25.0 (minor) #7263

Open

-            Ok(bytes) => match String::from_utf8(bytes) {
-                Ok(text) => text,
-                Err(_) => {
-                    let mime = mime_type
-                        .as_ref()
-                        .map(|m| m.as_str())
-                        .unwrap_or("application/octet-stream");
-                    format!("[Binary content ({}) - {} bytes]", mime, blob.len())
-                }
-            },
+            Ok(bytes) => {
+                let byte_len = bytes.len();
+                match String::from_utf8(bytes) {
+                    Ok(text) => text,
+                    Err(_) => {
+                        let mime = mime_type
+                            .as_ref()
+                            .map(|m| m.as_str())
+                            .unwrap_or("application/octet-stream");
+                        format!("[Binary content ({}) - {} bytes]", mime, byte_len)
+                    }
+                }
+            }

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alexhancock commented Feb 11, 2026

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